II. Risk of End-Stage Renal Disease Following Live Kidney Donation
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- Please summarise this article in your own words
- What is the level of evidence provided by this article?
- Why the conclusion of this study is different from the article above (article 1)?
Dear All
I’m impressed with colleagues who noticed the difference between the results of this article and that one in Journal club 1. Of course mainly due to a significant difference in the control group.
What is the duration of follow-up in both articles?
What is the sample size presented in both articles?
The duration of article 1 ; Long term consequences of kidney donation was from 1963 to 2007, about 44 years, and the sample size was 3698 kidney donors.(long duration, but smaller sample size than second article).
While the duration of article 2 ; Risk of ESKD following kidney donation, was from 1999 to 2011 about 12 years, and the sample size was 96 217 kidney donors ( shorter duration time than the 1st article, while the sample size was larger).
ARTICLE 1: Study population of 3698 but GFR was estimated in only 255 with 4 years follow up
ARTICLE 2: study population of 96217 with 15 years follow up (median 7.6 years)
In first article the follow up was for 4 years and the sample was small ( not include all donors)
Second article follow up 2 decades and include all donors
Article 1: duration of follow-up: 4 years, sample size: 3698.
Article 2: duration of follow-up: 7.6 years for kidney donors and 15 years for non-donors, sample size 96 217 kidney donors, 20 024 non-donors.
What is the duration of follow-up in both articles?
What is the sample size presented in both articles?
Article1: 44 years duration and the number of kidney donors included in the sample was 3698.
Article 2: Donation lasted for about 15 years, with a total sample size of 96 217 kidney donors.
Previous study-From November 1963 through December 2007, a total of 3698 nephrectomies in living donors were performed at the University of Minnesota. 4 years follow up.
In this study- From April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked, A total of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD, 15 years follow up.
Duration of follow up
Sample size
What is the duration of follow-up in both articles?
Article 1 4years.
Article 2 15years
What is the sample size presented in both articles?
article 1 – 3698
article 2 – 96217
Duration of follow up
the first one >>>> 4years
the second >>>> 15years
the sample size
the first article >>>> 3698
the second >>>> 96217
In the first article, the total number enrolled is 3698, but the number evaluated for GFR is 255. In the second article, a cohort of 96217 donors was matched to a similar number of nondonors from the U.S) in addition to a cohort of 20024 from the NHANESIII
The duration of post-donation follow-up in the first paper was >20 years. In the second paper maximum duration was 15 (mean 7.6) years.
Article one study population 3698 and duration follow up 4 yes
Article 2
study population 96217 with median follow up 7.6 years
What is the duration of follow-up in both articles?
Article 1: follow-up 12.2 + 9.2 years
Article 2: follow-up 7.6 years for donors and 15 years for the control group
What is the sample size presented in both articles?
Article 1: 3698 donors (255 were analysed)
Article 2: 96217rs
The duration of follow-up in both articles are as follows:
1) Article one had a follow-up of about 12.2 years while article two with a follow-up of about 7.6 years and a period of 15 years for the control group.
The sample size found in the two studies are:
1) The first study or article had about 3698 donors and about 225 were analyzed while the second article had 96127
What is the duration of follow-up in both articles?
What is the sample size presented in both articles?
Article-1; The duration from 1963 to 2007, about 44 years.
The sample size was 3698 kidney donors.
Article-2: the duration is from 1999 to 2011 about 12 years.
The sample size was 96 217 kidney donors (shorter duration time but larger sample size).
Article 1:
Population evaluated: 3698 donors from 1963 to 2007, so some donors had follow-up of 44 years (Longer duration follow-up of smaller sample size donors)
Article 2:
Population evaluated: 96217 donors with 15 years follow-up (shorter duration follow-up of a large sample size, an additional benefit of comparison with matched healthy nondonors)
Duration of Follow-up:
Article 1:
12.2 ± 9.2(Mean ± SD) years for Donors(cases)
Rate of ESRD in General population from 2007 annual data report of US Renal Data System as controls
Article 2:
Median follow up of 7.6 years for Donors(cases) versus 15 years for matched non donors (Controls)
Sample Size:
Article 1:
3698 Donors from 1963-2007.
From 2003 -2007, 255 non donors(controls) were matched 1:1 (using measured GFR, Urine Albumin excretion, HTN, general health status and QoL) with donors (Cases) from National Health and Nutrition Examination Survey (NHANES).
Article 2:
96217 Kidney donors from 1994-2011.
20024 matched controls (from NHANES III study) from 1988 to 1994
4 years follow up in article 1, 15 years follow up in article 2
3698 in article1, 96217 in article 2
What is the duration of follow-up in both articles?
Article 1: 44years for risk of ESKD in 3698 kidney donors
4 years 255 donors for GFR, urine Alb excretion, HTN, general health status
Article 2: median follow-up of 7.6 years (maximum, 15.0)
What is the sample size presented in both articles?
Article 1: 3698 kidney donors in 1963-2007 and 255 donors from 2003-2007
Article 2: 96 217 kidney donors, 20 024 participants of NHANES III
the sample size is 3698 in article 1 and 96217 in article 2
follow up peroid is 4 years in article1 and 15 years in article 2
What is the duration of follow-up in both articles?
First article was 12.2 ± 9.2 years and 15 years for second article .
What is the sample size presented in both articles?
The sample size is 3698 in the first article compared to 96,217 in the second article
This is a prospective case control study with level 3 evidence to study the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease. ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.The estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in kidney donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in the matched healthy nondonor counterparts (P < .001).
Larger sample size with longer duration of study.
Aim of the study:To compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics.
Conclusion:
-Compared with matched healthy nondonors, kidney donors
had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
article 2 has more candidates in study population and longer follow up period
Ø Study to compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics
Ø A cohort of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD.
Ø Maximum follow-up was 15.0 years; median follow-up was 7.6 years (interquartile range [IQR], 3.9-11.5 years) for kidney donors and 15.0 years (IQR, 13.7-15.0 years) for matched healthy nondonors.
Ø Main Outcomes and Measures: Cumulative incidence and lifetime risk of ESRD.
Ø Results:
Among live donors, with median follow-up of 7.6 years (maximum, 15.0), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation. Among matched healthy nondonors, with median follow-up of 15.0 years (maximum, 15.0), ESRD developed in 36 nondonors in 10.7 (3.2) years, drawn from 17 ESRD events in the unmatched healthy nondonor pool of 9364. Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in kidney donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in their matched healthy nondonor counterparts (P < .001). This difference was observed in both black and white individuals, with an estimated risk of 74.7 per 10000 black donors (95% CI, 47.8-105.8) vs 23.9 per 10000 black nondonors (95% CI, 1.6-62.4; P < .001) and an estimated risk of 22.7 per 10 000 white donors (95% CI, 15.6-30.1) vs 0.0 white nondonors (P < .001). Estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened nondonors (general population), and 14 per 10 000 healthy nondonors.
Ø Compared with matched healthy nondonors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase was small.
What is the level of evidence provided by this article?
Level 3
Why the conclusion of this study is different from the article above (article 1)?
Ø Matched control group of nondonor
1. Please summarise this article in your own words
The study compared the risk of developing ESRD in 96 217 live kidney donors between april1994-nov 2011 with healthy cohort of 20 024 non donors who are low risk of renal failure and free of contraindications to live donation. These were participant of the 3rd national health and nutrition examination survey (NHANES111).
The study follow up was 15 yrs , median follow up was 7.6 yrs for kidney donors and 15 yrs for matched healthy non donors.
The study showed that 23 white, 33 hispanic and 75 black donors per 10 000 developed ESRD after donation. As compared to the control where 23 white, 26 hispanic and 51 black had ESRD.
Importantly they also found out that kidney donors carries higher risk of developing ESRD throughout their life time (90 per 10 000) than healthy individuals who did not donate but still lower than general population (326 per 10 000).
The study has its strength including large sample size and duration of follow up , but it also has its limitations including donors are carfully screened and they may be healthier than the donors. More over follow up period may not have permitted to fully understand the long term risk of donation . also the difference in the years of data collection between the donors and the control might has some influence of the results obtained as in the recents yrs more of hypertension and obesity and diabetes appeared as compared to the previous decade .
2. What is the level of evidence provided by this article?
Level 3 , case controlled study ,retrospective controlled
3. Why the conclusion of this study is different from the article above (article 1)?
Population of the study is larger and duration of the study is longer. Also the control is different ,
Absolute Risk Increase
Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors
Absolute risk of ESRD was highest among both black donors at 74.7 per 10 000 (95% CI, 47.8-105.8) and black nondonors at 23.9 per 10 000
Cumulative Incidence by Subgroup
Estimated Lifetime Risk
Live donors had a higher estimated risk of ESRD than healthy nondonors across all ages (Figure 3). Those who had donated at some point before the age of 30 years had an estimated risk of 5 per 10 000 compared with healthy nondonors who had estimated risk of 0 per 10 000. Similarly, by age 50 years, estimated risk in donors was 28 per 10 000 vs 1 per 10 000 in nondonors
Discussion
Compared to comparably healthy persons who did not donate (14 per 10,000), kidney donors were assessed to have a slightly increased lifetime risk of getting end-stage renal disease (ESRD) (90 per 10,000), but still far lower risk than the overall population (326 per 10 000).
lifetime risk of ESRD in live donors is no higher than in the general demographics-matched US population
Strength points of the study :
The inclusion of every kidney donor in the United States over almost two decades
the comparison with a healthy nondonor cohort matched on a wide variety of demographic and clinical factors
the large sample size of study populations
draw conclusions specific to race/ethnicity subgroups, providing crucial information for both those thinking about donation and the nearly 100 000 Americans still alive after a donor nephrectomy
Limitations of the study :
First off, our conclusions may only be loosely generalizable to donors in other nations because they were based on two cohorts of healthy Americans
Second, donors are thoroughly screened, and it is plausible that even after screening by NHANES history, physical, and laboratory tests, the donors were healthier than the healthy nondonors
Third :15 years in investigation, which may have prevented the study from completely understanding the long-term danger of donation
Conclusion:
kidney donors had a higher chance of developing ESRD, however the increase in absolute risk was rather slight
Level of evidence II
Risk of End-Stage Renal Disease Following Live Kidney Donation
The study recruited 96 217 kidney donors from April 1994 to November 2011 compared to 20 024 participants, taken as control from NHANES III and compared development of ESRD. They were followed up for a median of 7.6 years, maximum follow up was for 15years.
The study showed:
Limitations:
The study concluded that when comparing with a matched cohort of healthy nondonors, kidney donors had an increased risk of ESRD; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
2. What is the level of evidence provided by this article?
Level 3 case control study.
3. Why the conclusion of this study is different from the article above (article 1)?
Living kidney donation is considered the very important pillar of the common kidney donor pool besides deceased kidney organs, living kidney donations comprising around 40% of all transplants performed worldwide. The main concern when proceeding to living kidney donation is to avoid doing harm to the living donor. The expected risks to the living kidney donor are minimal when compared with the benefits for the recipient who will live a near normal life.
There is expected reduction in GFR of around 40% from the baseline GFR, although it was thought that the risk of ESRD will be lower or no different compared to the general population, but we have to put in mind that the living donors are selected candidates who are eligible for organ donation unlike the general populations. So, comparison must be with the same category of people.
There were two studies have compared living donors with healthy non donors. The first study concluded that the long-term risk with median follow up time of 15.1 years for ESRD was about 11-fold higher in potential living donors compared to healthy nondonors and this conclusion can be explained with a hereditary cause since all studied donors were living related and the suggested causes were predominantly immunological diseases. In the second study, the they found that the long-term risk of ESRD after nearly 7 years follow up was around 8-fold higher in living donors in comparison to healthy nondonors. Both studies concluded that, the absolute increase in risk of ESRD after 15 years from donation was below 0.5% .
Study design: 96217 kidney donors from 1994 to 2011 in USA; compared to healthy general population
Aim of study: comparison the risk of ESRD in potential donors with general population.
Follow up was done over 15 years; median of 7 years.
Results:
The risk of ESRD in donors’ group was 90/10,000 compared with lower risk in healthy control group that was 14/10,000.The risk of ESRD in general population is 326/10,000. The risk was higher in donors aged more than 50 years and in male donors than female donors. There was no racial difference.
This study had included all donors from 1994 to 2011, their number was more than 96,000, using control group with healthy matched donors and in comparison with general population. The aforementioned points give strength to the study.
Kidney donation increases risk of ESRD in comparison with healthy controls.
It is a case control study with level III evidence.
The conclusion of this study is different from that in article 1 because of different control group which included all ethnicity with bigger sample size compared with article 1.
This study aim to calculate the risk of developing ESRD after kidney donation.
STUDY DESIGN :
96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD, which was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant, whichever was identified first. Maximum follow-up was 15.0 years; median follow-up was 7.6 years (interquartile range [IQR], 3.9-11.5 years) for kidney donors and 15.0 years (IQR, 13.7-15.0 years) for matched healthy nondonors.
Result :
The study shows that there is a small risk for developing ESRD espessially in African-American donors .
Level 2
Because this study design a better and more acurrate controll groub
Increase the number of study .
increase the duration of followup .
Q1- Please summarise this article in your own words.
Abstract :
Importance —Risk of end-stage renal disease (ESRD) in kidney donors has been compared to similarly screened healthy nondonors.
Objectives
—To compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics.
Design, Settings, and Participants:
—A cohort of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey had been involved in this study. Maximum follow-up was 15.0 years; median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy nondonors.
Main Outcomes and Measures—Cumulative incidence and lifetime risk of ESRD.
Results:
Among live donors, , ESRD developed in 99 individuals in a mean of 8.6 years after donation.
Among matched healthy nondonors, ESRD developed in 36 nondonors in 10.7 years.
Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 in kidney donors and 3.9 per 10 000 in their matched healthy non donor counterparts . This difference was observed in both black and white individuals.
Conclusions and Relevance:
—Compared with matched healthy non donors, kidney donors had an increased risk of ESRD over a median of 7.6 years; but the absolute risk increase was small.
Methods
Live Kidney Donors: all adult live donors between April 1, 1994, and November 30, 2011, were included in this study.
Matched Non donors: The matched non donor population was drawn from the Third National Health and Nutrition Examination Survey (NHANES III).
Matching s based on age, sex, self-identified race, educational background, body mass index (BMI), smoking history, and systolic blood pressure.
Cumulative Incidence of ESRD: Kaplan-Meier methods were used to estimate cumulative incidence of ESRD.
Estimated Lifetime Risk of ESRD: Kaplan-Meier methods were used to estimate lifetime risk of ESRD,
Absolute Risk Increase:
The difference in cumulative incidence between the live donors and the non donors reported as the absolute risk increase.
Frequency and Timing of ESRD:
Among live donors, , ESRD developed in 99 individuals in a mean of 8.6 years after donation.
Among matched healthy nondonors, ESRD developed in 36 nondonors in 10.7 years.
Absolute Risk Increase
Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 in donors and 3.9 per 10 000 in healthy nondonors .
Absolute risk of ESRD was highest among both black donors at 74.7 per 10 000 and black nondonors at 23.9 per 10 000, and the absolute risk increase was also highest in black .
estimated lifetime absolute risk increase of 76 per 10 000.
Discussion:
This study report that , ESRD occurred in 23 white, 26 Hispanic, and 51 black individuals because they donated a kidney.
This study also noted that donors had at higher estimated risk of developing ESRD throughout their lifetimes (90 per 10 000) than similarly healthy individuals who did not donate (14 per 10 000), but still a much lower risk than the general population (326 per 10 000).
The association between donor nephrectomy and risk of ESRD association in this study was strong and was statistically significant within each race/ethnicity stratum.
Ibrahim et al also noted development of ESRD in 30 per 10 000 of these donors 22.5 (10.4) years after donation.
Study strength:
1- the inclusion of every kidney donor in theUnited States over nearly 2 decades, the highly reliable linkage-based ESRD ascertainment,
2- the comparison with a healthy nondonor cohort matched on a wide range of demographic and clinical variables.
3- the large sample size of the study .
4- the inclusion of an unscreened nondonor population demographically matched to the donor population
limitations of this study are :
1) ourinferences were based on 2 cohorts of healthy individuals from the US and may generalize imperfectly to donors in other countries.
2) donors are meticulously screened, and it is possible that the donors were healthier than the healthy nondonors, even after screening by NHANES history, physical, and laboratory testing.
3) the follow-up in this study, was limited to 15 years and may not have permitted us to fully understand the long-term risk of donation.
4) It is also worth noting that the donors in this study donated between 1994-2011, whereas the non donors to whom they were matched entered NHANES III between 1988-1994.
Conclusion:
Compared with a matched cohort of healthy nondonors, kidney donors had an increased risk
of ESRD; however, the magnitude of the absolute risk increase was small.
Q2- What is the level of evidence provided by this article?
Level of evidence is 2
Q3- Why the conclusion of this study is different from the article above (article 1)?
Because this study is powered by
– Very well designed study.
– Large sample size.
– Care full patient and control group selection.
– Long term follow up period.
Please summarize this article in your own words
Study group: 96217 kidney donors in the USA from 1994 to 2011.
Control group: healthy general population.
Aim: compare the risk of ESRD in potential donors compared to general population.
Follow up: over 15 years with median of 7 years.
Definition of ESRD: starting dialysis or receiving a transplant or on the waiting list of transplants.
Results:
The risk of ESRD in donors’ group was 90/10,000 compared to lower risk in healthy control group that was 14/10,000. However, the risk of ESRD in general population is 326/10,000. The risk was higher in donors aged above 50 years and in male donors than female donors. There was no racial difference.
This study had included all donors in the USA from 1994 to 2011, their number was more than 96 thousand, using control group with healthy matched donors and in comparison, to general population as well. All the above-mentioned points give strength to the study.
Kidney donation increases the risk of developing ESRD in comparison to healthy controls.
What is the level of evidence provided by this article?
Case control study with level III evidence.
Why the conclusion of this study is different from the article above (article 1)?
Because of different control group which included all ethnicity, and bigger sample size compared to article 1.
Please summarize this article in your own words
Study design:
· This study compared 96217 kidney donors to healthy matched donors.
· The risk of ESRD was compared in donor with matched healthy non donors
· The follow- up period was 15 years(mean was 7 years)
Results:
· The risk of ESRD was higher in kidney donors as compared to non-donors.
· There were no difference between ethnic groups.
· 83 donors who developed ESRD were biologically related to recipient
Conclusion:
· There is higher risk of ESRD in kidney donors for ESRD when compared to healthy non donors. however, the absolute risk increase was trivial compared to matched non-donor control population .
· If donors are related to recipient these donor have higher risk of ESRD.
What is the level of evidence provided by this article?
Level 2 evidence
Prospective Observational cohort study with controls. Subjects are exposed to a risk (kidney donation ) case) and we observe for outcome (ESRD)
Why the conclusion of this study is different from the article above (article 1)
· larger donor pool(larger sample size)
· multiple ethnicities(black and white)
· potential healthy donors as control group rather than general population- as the general population
· longer duration of follow-up
This is a cohort study of 96 217 kidney donors and a cohort of 20 024 participants who were followed-up to 15.0 years .it proved that kidney donors had an high risk of ESRD with small absolute risk.
The control group was drawn from the Third National Health and Nutrition Examination Survey (NHANES III). Then those who had contraindications to kidney transplantation were excluded and identified as healthy, screened non-donor population. Then they were individually matched with replacement to live donors based on age, sex, race, educational background, body mass index smoking history, and systolic blood pressure.
Though ESRD developed more in donors compared with matched healthy non-donors, it is still less not higher than the general population risk
Strengths of the study:
· included of every kidney donor in the United States over nearly 2 decades
· the highly reliable linkage-based ESRD ascertainment
· the comparison with a healthy nondonor cohort matched on a wide range of demographic and clinical variables
· the large sample size of our study populations
· race/ethnicity subgroups,
· inclusion of an unscreened nondonor population
Limitations
· based on 2 cohorts of healthy individuals from the United States and may generalize imperfectly to donors in other countries.
· donors are meticulously screened, and it is possible that the donors were healthier than the healthy nondonors, even after screening by NHANES history, physical, and laboratory testing.
· the follow-up , although long enough to identify a risk of ESRD in donors, was limited to 15 years and may not have permitted full understanding of the long-term risk of donation;
· donors in this study donated between 1994-2011, whereas the nondonors to whom they were matched entered NHANES III between 1988-1994.
· With increasing incidence of ESRD over the last 2 decades, it is possible that recent cohort of donors may had developed a higher risk of ESRD
· This study screened for more than 30 medical conditions, thereby attenuating the possibility that the increased rates of ESRD in donors were attributable to secular trends rather than to donation
The level of evidence is 2
Summary of Risk of End-Stage Renal Disease Following Live Kidney Donation
Introduction:
Physiological sequalae resulting from kidney donation remains less well characterized.
This study comparing donors with other donors can not account for the fact that race and sex are associated with ESRD in non-donor as well.
The aim of this study of this study was to know the risk of ESRD following live donation comparing the incidence of ESRD in live donors with their healthy non-donor counterparts.
Results:
Among 20024 unscreened adult NHANES111 participants 9364(47%) had no contraindication to kidney donation
Frequency and timing of ESRD:
ESRD developed in 99 individuals, 50 were white 83 biological related to the recipient.
Absolute risk increase:
Absolute risk of ESRD was highest among both black donors and black non-donors.
Estimated life time risk:
Live donors had a higher estimated risk of ESRD than healthy non-donors across all ages.
Discussion:
No association between donor nephrectomy and risk of ESRD has been reported before.
This association in this study was strong and was statistically significance with each race/ethnicity stratum.
Strength of this study:
1. Long donation of the study are 2 decades
2. Matched unscreened non-donor population
Limitation of the study:
· Study interference based on 2 cohort of healthy individual from the united states and imperfect to donors in other donors.
· Study short duration 15 years
· ESRD rate in donors did not change over time
· In this study donor success for more than 30 medical condition
Conclusion:
Compared with a matched cohort of healthy non-donors, kidney donors has an increase risk of ESRD, however the absolute risk was small.
This finding can be induced in donors counselling.
evidence level 3
this study the control group are screening living donors but in the previous study from the general population , the sample size is larger in this study and duration of the follow up.
1. Please summarise this article in your own words
The study compared the risk of developing ESRD in 96 217 live kidney donors between april1994-nov 2011 with healthy cohort of 20 024 non donors who are low risk of renal failure and free of contraindications to live donation. These were participant of the 3rd national health and nutrition examination survey (NHANES111).
The study follow up was 15 yrs , median follow up was 7.6 yrs for kidney donors and 15 yrs for matched healthy non donors.
The study showed that 23 white, 33 hispanic and 75 black donors per 10 000 developed ESRD after donation. As compared to the control where 23 white, 26 hispanic and 51 black had ESRD.
Importantly they also found out that kidney donors carries higher risk of developing ESRD throughout their life time (90 per 10 000) than healthy individuals who did not donate but still lower than general population (326 per 10 000).
The study has its strength including large sample size and duration of follow up , but it also has its limitations including donors are carfully screened and they may be healthier than the donors. More over follow up period may not have permitted to fully understand the long term risk of donation . also the difference in the years of data collection between the donors and the control might has some influence of the results obtained as in the recents yrs more of hypertension and obesity and diabetes appeared as compared to the previous decade .
2. What is the level of evidence provided by this article?
Level 3 , case controlled study ,retrospective controlled
3. Why the conclusion of this study is different from the article above (article 1)?
Population of the study is larger and duration of the study is longer. Also the control is different ,
The aim and objective of this article was to compare the risk association of donation and ESRD with control group.
It was done in live donors with median follow-up 7.6 years to 15 years(absolute risk 30.8 per 10000 donors and 3.9 per 10000 of control group). ESRD develop in 99 donors in 8,6 years post-donation.
The article sample was small (3698), duration 1963 to 2007, and control group was general population, while in article 2 the sample size is large (96217) duration 1994 to 2011.
Conclusion;
The life risk of ESRD is higher then control group, although, the magnitude of absolute risk increase was small.
cohort study, level II
This is a retrospective cohort study with an established control group, which gives it a level II of evidence.
Data were collected from April 1994 to November 2011 with 96,217 (up from 255 in the first study) living donors who underwent nephrectomy throughout the US (unlike the first study which was restricted to a single center).
The control group in a 1:1 ratio using the NHANES III database considering only individuals with the same characteristics as potential donors (unlike the general population in the first study) from 1988 to 1994.
The aim of the study is to assess the risk of end-stage renal disease in those donors who underwent nephrectomy.
Almost 80% of the donors were under 50 years old, mostly women and whites. 67.6% were related to each other, with a quarter obese (BMI above 30), less than 10% hypertensive, and 24.2% smokers.
Donors had a higher risk of ESRD compared to the control group, regardless of age, being higher in blacks and Hispanics. Compared with the general population, without differentiating the risk factors, donors who underwent nephrectomy are still at lower risk.
Even with high risk compared to populations with similar risk factors, the magnitude of this risk is small, but the potential donor must be aware of the risks involved.
Level of evidence is III
The risk of ESRD among kidney donor is about 7.6%
About 6000 of donor accepted nepherctomy risk to help his family for survival
The amplitude of increasing risk is small
About 6000 healthy adults in US accept the risk of kidney donation to help their family members or friends to improve survival . This study was done to compare the risk of ESRD in living donor with their healthy non donors.
_All kidney donors in US between April 1, 1994 and November 30,2011 about 96217 live donors was included in this study.
A healthy screened matched non donors was drawn from NHANES between 1988 and 1994 about 20024 individuals
This matching was based on age, sex, race , education, BMI, smoking history, Systolic blood pressure.
Compare the risk of ESRD in two groups after a follow-up for 15 years, median follow-up was 7.6 years .
Results
Among 96217 live donors, 78.3% were younger than 50 years , 59% were women, 74.6%were white, 67.6% were related to recipients, 25.2% were obese , 9% were HTN.
The study showed that kidney donors had a higher estimated risk of developing ESRD their lifetimes ( 90 per 10.000) than matched healthy non donors ( 14 per 10.000) , but still a much lower risk than general population ( 326 per 10.000)
In conclusion : compared with matched healthy non donors, kidney donation had an increased risk of ESRD, however the magnitude of the absolute risk increase was small
Level of evidence III
Why the conclusion of this study is different from the article above ?
Because difference in the sample size
In article one . About 3698 live donors , only 255 were analyzed
In article 2 . About 96217 live donors were included in this study
Difference in duration of follow-up.
In article 1 . mean +/- SD of 12.2+/- 9.2 years after donation
In article 2 . Follow up for 15 years for matched healthy non donors and median follow-up was 7.6 years for kidney donors.
Difference in control group in the second article , the control group concluded matched non donors population and this matching based on age , sex, race , education, BMI, Smoking history, Systolic blood pressure.
This study was done to estimate the risk of developing ESRD after kidney donation so comparison was done between donor and healthy non donor rather than general population
3- Why the conclusion of this study is different from the article above (article 1)?
thanks
Summary:
Objectives: compare the risk of ESRD in kidney donor with that of a healthy cohort of non-donors who are at equally low risk of renal disease and free of contraindications to live donation.
Design, settings, and participants:
A cohort of 96217 donors in US between April 1994 and November 2011. And cohort of 20024 participants of the third national health and nutrition examination survey (NHANES III) were linked to centers for medicare and Medicaid services data
End point: development of ESRD which was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant.
Follow-up period was 15 years. Median follow-up period was 7.6 years for kidney donors and 15 years for matched healthy non-donors.
Main outcomes and measures: cumulative incidence and lifetime risk of ESRD.
Results:
Estimated risk of ESRD events at 15 years after donation was 30.8 per 10000 in kidney donors and 3.9 per 10000 in their matched healthy non-donor counterparts (p < 0.001). ESRD develop after median period of 7.6 years in kidney donor and over period of 15 years of healthy non-donors.
Estimated Lifetime Risk
Live donors had a higher estimated risk of ESRD than healthy non-donors across all ages.
Discussion:
23 white, 33 Hispanic, and 75 black donors per 10 000 developed ESRD after kidney donation. Most of the ESRD occurred because they donated a kidney, while some cases resulted from the inherent risk of ESRD. The study also, determined that kidney donors had a somewhat higher estimated risk of developing ESRD throughout their lifetime than similarly healthy individuals who did not donate. (90 per 10 000 vs 14 per 10 000), but still a much lower risk than general population 326 per 10 000).
The study revealed strong and significant association between donor nephrectomy and risk of ESRD within each race/ethnicity stratum, and this association was not reported before.
This result was extension to Ibrahim et al who observed decline in renal reserve, (decline of greater than 24 mL/min/1.73 m2 in 12.2 years after donation, and he further noted development of ESRD in 30 per 10 000 donors 22.5 years after donation.
Strengths of the study:
1- Inclusion of every kidney donor in the US over nearly 2 decades.
2- Highly reliable linkage-based ESRD ascertainment.
3- The comparison with a healthy non-donor cohort matched on a wide range of demographic and clinical variables.
4- Large sample size.
5- Inclusion of an unscreened non-donor population demographically matched to the donor population.
Limitations:
1- The deductions in the study were based on 2 cohorts of healthy individuals from the US and may not be generalized to donors in other countries.
2- Donors are meticulously screened, and it is possible that the donors were healthier than the healthy non-donors.
3- The follow-up period limited to 15 years although long enough to identify a risk of ESRD in donors.
4- The donors donated between 1994- 2011, whereas the non-donors to whom they were matched entered NHANES III between 1988 – 1994. With increasing incidence of ESRD over the last 2 decades. This may raise wonder that higher risk of ESRD was just by the influence of these secular trends. This secular trends in the general population were attributed to conditions such as morbid obesity, DM, and hypertension. These conditions are screened for carefully and some of them are contraindication to donation. Also, the study screened for more than 30 medical conditions, thereby attenuating the possibility that the increased rates of ESRD in donors were attributed to secular trends rather than to donation.
Conclusion:
Kidney donors had an increased risk of ESRD when compared to matched cohort of healthy non-donors. Although the magnitude of the risk was small. But it is important to consider in discussion with persons welling to live kidney donation.
Level of evidence III
Why the conclusion of this study is different from the article above?
Because:
1- The control group was matched healthy general population, while in this study was matched healthy non-donors that screened as the donors.
2- Sample size,
3- In the first article was 3698 donors (255 donors analysed), while in the second article was 96217 donors
4- Follow-up period
In the first article was 12.2 +_ 9.2 years, while in the second was 7.6 yrs for the donors and 15 yrs for the control group
· This study compares the incidence of ESKD between donors and similar healthy non-donors, who have no contraindication for donation
· Participants: 96 217 kidney donors in the United States (between April 1994 and November 2011) and 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III)
· Median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy nondonors.
· More than half of donors were: < 50years, females, white, higher educated, and biologically related to their recipients.
· A quarter of donors were obese, or smokers, and less than 10% had Systolic Bp>140
· Live donors have more risk than healthy nondonors to develop ESKD across all ages
· Strength of the study due to:
-Large sample size
-wide range of demographic and clinical variables were matched in the comparison between donors and nondonors
– Inclusion of an unscreened nondonor population demographically matched to the donor population
· Limitations of the study:
-Restricted to people in US
-As donors were screened well, they could be healthier than nondonors
-Follow up was maximum 15 years, and risk may increase after that
– Donors in this study donated between 1994-2011, whereas the nondonors to whom they were matched entered NHANES III between 1988-1994
What is the level of evidence provided by this article?
This is a case control study, evidence 3.
I think it is not 2, because nephrectomy not done during the study, we are only observing the outcome of old nephrectomy.
Why the conclusion of this study is different from the article above (article 1)?
Larger sample, longer follow up, more variables, data collection more reliable
summary of the article:
· kidney donors had slightly higher risk to develop ESKD, compared to healthy non donors who did not have any risk factor for CKD development.
· Healthy non donors were matched to donors regarding age, gender, BMI, blood pressure and smoking history (non-modifiable risk factors)
· Previous comparative studies had 2 limitations: small sample size and absence of matched healthy controls (screened for common health problems as done in donors, and not having the common risk as in general population. In addition, the higher risk of ESKD among black races and male gender. Comparing to general population, sure will have similar rate as it is wide base with many risk factors to develop CKD as diabetes and hypertension, unlike healthy screened donors with exclusion of many health problems.
· ESKD was defined when started dialysis, listed on waiting list for kidney transplantation (whether living or deceased).
· The mean follow-up duration was 7.5 for donors and 15 years for healthy controls.
· the point of weakness here is non simultaneous cohorts of controls and studied donors, with different incidence of CKD as increased pandemic of obesity, DM and HTN.
· Prospective cohort study, level of evidence: III
· different conclusion: due to different control group (healthy non donors without risk to develop CKD. In addition, larger donor pool (96,217 in comparison to 3698 donor in the previous article in club 1) , included both white and black, and longer duration of follow up 15 years compared to 12.2 ± 9.2 years (for lifetime ) and 4 years (for assessment of GFR, urinary ACR, hypertension, and QOL in the previous article.
Please summarise this article in your own words
Abstract:
The transplant community, in due diligence to donors, should understands the risk of
donation to the fullest extent possible and communicates known risks to those
considering donation.
Compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors
who are at equally low risk of renal disease and free of contraindications to live donation
and to stratify these comparisons by patient demographics.
Results
Frequency and Timing of ESRD
Among live donors, with median follow-up of 7.6 years (maximum, 15.0 years), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.
Absolute Risk Increase
Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors
Estimated Lifetime Risk
Live donors had a higher estimated risk of ESRD than healthy nondonors across all ages
Conclusion:
Compared with matched healthy non-donors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk was small.
What is the level of evidence provided by this article?
Level 3 (case-control study).
Why the conclusion of this study is different from the article above (article 1)?
This study found that live donors are at increased risk of ESRD, although the risk is small, while the previous study showed that live kidney donors are not at increased risk of ESRD; the main difference is in the control group, the previous study used the general population as a control group while this study selected healthy people who have no contraindications for donation.
Importance of this study is to estimate the risk of ESRD in living kidney donors in comparison to similarly screened healthy nondonors.
Methods
A cohort of 96 217 kidney donors between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD
Among 20 024 unscreened adult NHANES III participants, 9364 (47%) had no identified contraindication to kidney donation and were matched 1:1 to donors to create a healthy nondonor cohort of 96 217.
Results
-in live donors, with median follow-up of 7.6 years (maximum, 15.0), and in healthy nondonors, with median follow-up of 15.0 years (maximum, 15.0).
-ESRD in donors developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.
-ESRD developed in control group in 36 case in 10.7 (3.2) years.
– Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 in kidney donors and 3.9 per 10 000 in their matched healthy nondonor counterparts (P < .001).
– risk of ESRD was higher in black donors.
-Estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened nondonors (general population), and 14 per 10 000 healthy nondonors.
-findings are an extension of those by Ibrahim et al who observed a decline in renal reserve in as many as 1400 per 10 000 carefully selected white donors, from a mean (SD) predonation glomerular filtration rate (GFR) of 84mL/min/1.73 m2 to a post-donation GFR of less than 60 mL/min/1.73 m2 (a decline of greater than 24 mL/min/1.73 m2) in 12.2 years after donation,and development of ESRD in 30 per 10 000 of these donors 22.5 years after donation.
cumulative incidence of ESKD per 15 years increased wigh age to be 54.6 among those aged 50-59 years And 70.2 among those aged more than 60 years.
cumulative incidence of ESKD per 15 years was also different with sex
,more in black men than women and more in white men than women .
Conclusions
Compared with matched healthy nondonors, kidney donors had an increased risk of ESRD over a median of 7.6 years; but risk increase was small.
Strength points over article 1
-selection of control group to be fully screened as donors not general population which might have different risk factors for ESRD.
– large sample size.
-long follow up period sufficient to reach the end point (ESRD).
– results were different in this article than article 1, and risk of ESRD was found to be high in donors than matched control group.
Level of evidence ;III case control study
Please summarize this article in your own words
Aim of study: To estimate risk of ESRD in donors compared to well matched healthy non donors
Study Design:
Cases: 96217 kidney Donor from 1994 to 2011 in US
Controls: 20024 healthy non donors from NHANES III group from 1988 to 1994 in US
Definition of ESRD: Initiation of Maintenance HD, placement on waiting list or receipt of kidney transplant (Living or Deceased)
Duration of follow up: Median follow up is 7.6 years and 15 years in Donor and non-donors respectively
Results:
Absolute risk:
30.8/10000 in donors versus 3.9/10000 in healthy non donors.
Highest risk 74.7/10000 in Black Donors versus 23.9/10000 in non-black donors
Risk in Black donors>Hispanic>white donors
Estimated Lifetime Risk: 90/10000 in Donors versus 14/10000 healthy non donors
Strengths:
Large Sample size
Well matched control group
Inclusion of all donors in 2 decades in US
Limitations:
Not applicable to other country than US
Follow up limited to 15 years
What is the level of evidence provided by this article?
Case Control Study, Level of evidence 3
Why the conclusion of this study is different from the article above (article 1)?
This study included large number of cases and well-matched controls rather than general population, over a considerable long period and hence conclusion is different
1- Article summary:
Aim of the study:
To compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics.
Design, and Participants—A cohort of 96,217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20,024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centres for Medicare & Medicaid Services data to ascertain the development of ESRD. ESRD: defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant. In this cohort, medical information was obtained from patient self-report, physical examination, and radiologic and laboratory test results at NHANES III enrolment between 1988 and 1994. A healthy, screened nondonor population was derived from adult NHANES III participants by excluding those with identified contraindications to kidney transplantation
Maximum follow-up was 15.0 years; median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy nondonors.
Primary Outcomes and Measures—to measure incidence and risk of ESRD.
Results—Among live donors, with a median follow-up of 7.6 years (maximum, 15.0), ESRD developed in 99 individuals with a mean (SD) of 8.6 (3.6) years after donation.
Among matched healthy nondonors, with a median follow-up of 15.0 years (maximum, 15.0), ESRD developed in 36 nondonors in 10.7 (3.2) years, drawn from 17 ESRD events in the unmatched healthy nondonor pool of 9364.
The estimated risk of ESRD 15 years after the donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in kidney donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in their matched healthy nondonor counterparts (P < .001). This difference was observed in both black and white individuals.
The estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened nondonors (general population), and 14 per 10 000 healthy nondonors.
Conclusions and Relevance—Compared with matched healthy nondonors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
2- Evidence level 2
3- Why the conclusion of this study is different from the article above (article 1)?
· Article-1; The duration from 1963 to 2007, about 44 years. While the Sample size was 3698 kidney donors.
· This article: the duration is from 1999 to 2011 about 12-15 years. But the Sample size was 96 217 kidney donors (shorter duration time but larger sample size).
Abstract:
The transplant community, in due diligence to donors, should understands the risk of
donation to the fullest extent possible and communicates known risks to those
considering donation.
Compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors
who are at equally low risk of renal disease and free of contraindications to live donation
and to stratify these comparisons by patient demographics.
Design, Settings, and Participants:
A cohort of 96 217-kidney donors in the United State.
and a cohort of 20 024 participants of the NHANES III were linked to Centers for
Medicare & Medicaid Services data to ascertain development of ESRD
Period:
Between April 1994 and November 2011.
Main Outcomes and Measures:
Cumulative incidence and lifetime risk of ESRD.
Results:
In both black and white patient among live donors, with median follow-up of 7.6 years
(maximum, 15.0), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years
after donation.
Among matched healthy nondonors, with median follow-up of 15.0 years (maximum,
15.0), ESRD developed in 36 nondonors in 10.7 (3.2) years, drawn from 17 ESRD
events in the unmatched healthy nondonor pool of 9364.
Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-
38.5) in kidney donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in their matched healthy
nondonor counterparts (P < .001).
Conclusions and Relevance:
Compared with matched healthy nondonors, kidney donors had an increased risk of
ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase
was small.
Strengths of the study:
The inclusion of every kidney donor in the United States over nearly 2 decades.
The highly reliable linkage-based ESRD ascertainment.
The comparison with a healthy nondonor cohort matched on a wide range of
demographic and clinical variables.
The large sample size of our study populations.
The inclusion of an unscreened nondonor population demographically matched to the
donor population.
Limitation:
First, our inferences were based on two cohorts of healthy individuals from the United
States and may generalize imperfectly to donors in other countries.
Second, donors are meticulously screened, and it is possible that the donors were
healthier than the healthy nondonors.
Third follow up was limited to 15 years and may not have permitted us to fully
understand the long-term risk of donation.
Level of evidence 11.
Better or matched control and longer follow up time.
Introduction
Every year in the United States, approximately 6000 healthy adults accept the risks of donor nephrectomy to help family members, friends, or even strangers improve survival and quality of life.
It is imperative that the transplant community the donor should understands the risk of donation to the fullest extent possible and communicates known risks to those considering donation.
To date, studies have shown that perioperative death is extremely rare and subsequent survival rates are comparable with healthy nondonors.
Study Design
A cohort of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD, which was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant, whichever was identified first.
Maximum follow-up was 15.0 years; median follow-up was 7.6 years (interquartile range [IQR], 3.9-11.5 years) for kidney donors and 15.0 years (IQR, 13.7-15.0 years) for matched healthy nondonors.
Results
In this national study of 96 217 live kidney donors linked to CMS data for reliable progress of ESRD, we estimated that approximately 23 white, 33 Hispanic, and 75 black donors per 10 000 developed ESRD after kidney donation
however, ESRD occurred in 23 white, 26 Hispanic, and 51 black individuals because they donated a kidney, whereas the remaining cases resulted from the inherent risk of ESRD.
We also determined that kidney donors had a somewhat higher estimated risk of developing ESRD throughout their lifetimes (90 per 10 000) than similarly healthy individuals who did not donate (14 per 10 000), but still a much lower risk than the general population (326 per 10 000).
Frequency and Timing of ESRD
Among live donors, with median follow-up of 7.6 years (maximum, 15.0 years), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.
Of donors who subsequently developed ESRD, 50 were 18 to 39 years old at the time of donation, 57 were men, 50 were white, and 83 were biologically related to the recipient
By contrast, among matched healthy nondonors, with median follow-up of 15.0 years (maximum, 15.0 years), ESRD developed in 17 individuals among the 9364 individuals in the nondonor pool, resulting in 36 ESRD events in matched nondonors in a mean (SD) of 10.7 (3.2) years after enrollment.
Estimated Lifetime Risk
Live donors had a higher estimated risk of ESRD than healthy nondonors across all ages
Those who had donated at some point before the age of 30 years had an estimated risk of 5 per 10 000 compared with healthy nondonors who had estimated risk of 0 per 10 000. Similarly, by age 50 years, estimated risk in donors was 28 per 10 000 vs 1 per 10 000 in nondonors, and by age 80 years, the estimated risk was 90 per 10 000 in donors vs 14 per 10 000 in nondonors, representing an estimated lifetime absolute risk increase of 76 per 10 000.
Nevertheless, live donors had much lower estimated lifetime risk of ESRD than did the general population by age 80 years, 90 per 10 000 in donors vs 326 per 10 000 in the general population.
The strengths of this study
1-the inclusion of every kidney donor in the United States over nearly 2 decades
2-the highly reliable linkage-based ESRD ascertainment
3-the comparison with a healthy nondonor cohort matched on a wide range of demographic and clinical variables.
1- Because of the large sample size of our study populations, we were able to estimate the incidence of a relatively rare event and to make inferences specific to race/ethnicity subgroups, providing critical information not only for those considering donation but also for the nearly 100 000 individuals in the United States living after a donor nephrectomy.
6-inclusion of an unscreened nondonor population demographically matched to the donor population.
limitations of this study
1-The inferences were based on 2 cohorts of healthy individuals from the United States and may generalize imperfectly to donors in other countries.
2-The donors are meticulously screened, and it is possible that the donors were healthier than the healthy nondonors, even after screening by NHANES history, physical, and laboratory testing.
1- the follow-up in this study, although long enough to identify a risk of ESRD in donors, was limited to 15 years and may not have permitted us to fully understand the long-term risk of donation
Conclusion
Compared with a matched cohort of healthy nondonors, kidney donors had an increased risk of ESRD; however, the magnitude of the absolute risk increase was small.
These findings may help inform discussions with persons considering live kidney donation.
Level 2
In this study the healthy non-donors used as control but the previous article use the general population as controls
This study done on long period of follow up
Big sample size studied in this article
Risk of End-Stage Renal Disease Following Live Kidney Donation
1. Please summarise this article in your own words.
Importance:
In previous studies, donors were compared with general population which was not the ideal control groups. This because are healthier than general population.
Design, Settings, and Participants
A total of 96 217 kidney donors from April 1994 to November 2011 compared to 20 024 participants, taken as control from Third National Health and Nutrition Examination Survey (NHANES III) were compared looking for development of ESRD. They were followed up for a mean of 7.6years, maximum follow up was for 15years.
Results
Among live donors, with median follow-up of 7.6 years (maximum, 15.0):
1. ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation. Among matched healthy nondonors, with median follow-up of 15.0 years (maximum, 15.0)
2. ESRD developed in 36 nondonors in 10.7 (3.2) years, drawn from 17 ESRD events in the unmatched healthy nondonor pool of 9364
3. Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in kidney donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in their matched healthy nondonor counterparts (P < .001).
4. Estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened nondonors (general population), and 14 per 10 000 healthy nondonors.
Discussion
In this national study we estimated that approximately 23 white, 33 Hispanic, and 75 black donors per 10 000 developed ESRD after kidney donation; however, ESRD occurred in 23 white, 26 Hispanic, and 51 black individuals because they donated a kidney, whereas the remaining cases resulted from the inherent risk of ESRD.
Our findings reaffirm the prevailing belief that lifetime risk of ESRD in live donors is no higher than in the general demographics-matched US population.
Strength &Limitations
The primary strengths of our approach were:
· The inclusion of every kidney donor in the United States over nearly 2 decades
· The highly reliable linkage-based ESRD ascertainment,
· Comparison with a healthy nondonor cohort matched on a wide range of demographic and clinical variable,
· Large sample size
· Inclusion of an unscreened nondonor population demographically matched to the donor population
Limitations:
· All population are from USA.
· Donors were meticulously followed.
· Length of follow up was limited to 15years.
Conclusion
Compared with a matched cohort of healthy nondonors, kidney donors had an increased risk of ESRD; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
2. What is the level of evidence provided by this article?
Level 111 case control study.
3. Why the conclusion of this study is different from the article above (article 1)?
There main reasons are:
1-The control group in this study is healthy non donors, not general population in whom undiagnosed renal disease or its risk factor may be there.
2-The larger number of this study allowed finding significant difference despite low incidence.
3-Follow up duration was longer allowing the cumulative incident to accumulate for some time.
Please summarise this article in your own words :
Title :
Risk of End-Stage Renal Disease Following Live Kidney Donation
Method:
retrospective cohort study
Sample size :
96217
Time :
April 1994 and November 2011 ( 17 years )
ESRD definition :
ESRD, which was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant, whichever was identified first
Follow up :
7.6 years for donors and 15 years for matched non-donors.
Results :
ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation. Among matched
healthy nondonors, ESRD developed in 36 in 10.7 (3.2) years
ESRD was also higher in black donor and white donors compared to matched non donors
What is the level of evidence provided by this article?
level III
Why the conclusion of this study is different from the article above (article 1)?
better control group
Bigger sample size
Longer f/u time
Please summarise this article in your own words :
1- ESRD was developed in 99 of all donors versus 36 of all matched non-donors ( 30.8 versus 3.9/10,000)
2- in black donors, ESRD was also higher than matched non-donors (74.7 versus 23.9/10,000)
3- in white donors, ESRD was also higher than matched non-donors (22.7 versus 0/10,000)
4- the estimated life time risk of ESRD was 90/10,000 in donors and 14/10,000 in healthy matched non-donors. while it was 326/10,000 in unscreened non-donors.
What is the level of evidence provided by this article?
Why the conclusion of this study is different from the article above (article 1)?
Summery:
The objectives of this study are to compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation.
Through this reporting ,all adult live donors between April 1,1994,and November 30,2011,were included in this study. Matched non donor population was drawn from the Third National Health and Nutrition Examination Survey(NHANES111).
Among live donors, with median follow-up of 7.6 years (maximum, 15.0 years), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation. Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors.
Compared with a matched cohort of healthy nondonors, kidney donors had an increased risk of ESRD
Level of evidence: level 3
Difference from the article above:
Control, non donor population matched to the case, donor population.
Large sample size of living donor and control group.
Prolonged duration of follow up for both groups.
1. Duration of follow-up: 4 years, sample size: 3698.
2. Duration of follow-up: Maximum follow-up was 15.0 years; median follow-up was 7.6 years, sample size 96 217 kidney donors, 20 024 non-donors.
The risk of ESRD in kidney donors has been compared with that in general population, but needs to be assessed with respect to healthy non-donors.
The study included 96,217 kidney donors from 1994 to 2011 and incidence of ESRD in them was compared with 9364 subjects from 20024 participants of NHANES III study (conducted between 1988 and 1994) after matching 1:1 with the donors and creating a healthy cohort of 96217 subjects.
The donors were followed up for a median period of 7.6 years while the controls were followed-up for 15 years. ESRD risk at 15 years in donors was 30.8 per 10000 as compared to 3.9 per 10000 in the control group. The risk was 74.7 per 10000 in black donors as compared to 23.9 per 10000 in block non-donors. The risk in whites was lowest at 22.7 per 10000 amongst the donors while it was 0 in the white non-donors. The risk of ESRD was highest in those with age more than 60 years (70.2 per 10000)
The lifetime risk of ESRD was 90 per 10000 in the donors as compared to 14 per 10000 in the non-donors and 326 per 10000 in general population.
So, as compared to matched healthy non-donors, a kidney donor has increased risk of developing ESRD, although of small magnitude, over a median of 7.6 years
The strengths of the study were inclusion of all donors in last 2 decades, comparison with non-donor healthy cohort, large sample size, and inclusion of a cohort involving general population for comparison purpose. The limitations were that the study involves US population, hence could not be extrapolated to other countries; meticulously screened donors could be healthier that the healthy non-donor population; follow-up was not long enough at 15 years and the donors and non-donors are from different era (donors: 1994-2011, non-donors: 1988-1994)
Level of evidence: Level 2: includes prospective comparative studies. Subjects have been exposed to a risk (kidney donation in this case) and we observe for outcome of interest (ESRD).
The conclusions are different because:
a) The controls are different. This study takes healthy non-donors as control while the first article took general population as controls
b) Follow-up: Longer in this study
c) Sample size: Bigger in this study, representing multi-ethnicities.
Kidney transplantation has been the main or best treatment for kidney failure. There has studies that have shown that living donors are at risk of kidney failure while others do not confirm the same point. This article objective is to compare the incidence of ESRD in living donors with those healthy non-donors.
The group of study involved a population of 96217 donors in the US between a period of 1994 to November 2011. Based on the article kidney failure was defined as placement on the waiting list, initiation of maintenance of dialysis and recipient of living of deceased donor kidney transplant.
From the study it was found that incidence of ESRD after 15 years of donation was about 30.8 per 10000 in living donors and about 3-9 per 10000 in healthy non-donors. It was found that the highest risk was among the black population and the Hispanic groups.
So, it was also found that ESRD was found in donors in all age group was higher when compared with healthy non-donors. With age, the risk also increases.
The article has good results as it relates to a period of over 2 decades, there was highly reliable linkage based ESRD ascertainment, there was a good compare with healthy non-donor cohort matched on a wide range of demographic and clinical variables, it used a large population and wide racial groups, and a large amount of medication conditions were screened.
The study was also limited when it comes to the possibility that donors being healthier than healthy non-donors, the study was limited to the US and may not be a true reflection to other countries and the study was limited to 15 years that may not have substantial time to access risks.
So based on the study it was found that when comparing healthy non-donor kidney living donors had an increased risk of having ESRD.
The level of evidence in this article is level 3
This study was different from the previous one when it relates to population size, there was different ethnic group involved, the duration of the study was different.
The goal of this study of this study was to better understand the risk of ESRD following live donation by comparing the incidence of ESRD in the live donor with their healthy nondonor counterparts.
Methods
Through this reporting ,all adult live donors between April 1,1994,and November 30,2011,were included in this study.
Matched non donors, the medical non donor population was drawn from the Third National Health and Nutrition Examination Survey(NHANES111).
Result
Among live donors ,with median follow -up of 7.6 years , ESRD develop in 99 individual in a median 8.6 years after donation.
Absolute risk of ESRD was highest among both black donors at74.7 per10000 and black nondonors at 23.9 per 10000.
The difference in ESRD per10000 at 15 years between biological related and unrelated donors .
There was no observed temporal trend in increase of ESRD between 1994 and 2011.
Live donors had a higher estimated risk of ESRD than healthy non donors across all ages.
Discussion
Life risk of ESRD in live donors is no higher than in the general demographics-matched US population. And our estimate of population -based risk of ESRD
(derived from unscreened NHANES 111 participants) was comparable with a recent estimate of 360 per 10 000 in general US population.
Strength of the study :
1- Large sample size.
2- The inclusion of an unscreened non donors population matched to the donors population.
Limitation of this study
1- 2 cohort of healthy individuals from united states and may generalize imperfectly to donors in other countries.
2- Donors are screened and it is possible that donor were healthier than the healthy nondonors ,even after screening by NHANES history, physical and laboratory.
Conclusion
Compared with a matched cohort of healthy nondonors ,kidney donors had an increased risk of ESRD : however ,the magnitude of the absolute risk increase was small .these finding may help inform discussion with person considering live kidney donation.
level3
this study has large sample size ,long duration of follow up and ideal control group.
The objectives of this study are to compare the risk of ESRD in kidney donors with that of a healthy cohort of nondonors who are at equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics
Results
Frequency and Timing of ESRD
Among live donors, with median follow-up of 7.6 years (maximum, 15.0 years), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.
Absolute Risk Increase
Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors
Estimated Lifetime Risk
Live donors had a higher estimated risk of ESRD than healthy nondonors across all ages
Discussion
determined that kidney donors had a somewhat higher estimated risk of developing ESRD throughout their lifetimes (90 per 10 000) than similarly healthy individuals who did not donate (14 per 10 000), but still a much lower risk than the general population (326 per 10 000).
some limitations of this study are important to note.
First, the inferences were based on 2 cohorts of healthy individuals from the United States and may generalize imperfectly to donors in other countries.
Second, donors are meticulously screened, and it is possible that the donors were healthier than the healthy nondonors, even after screening by NHANES history, physical, and laboratory testing.
Third, the follow-up in this study, although long enough to identify a risk of ESRD in donors, was limited to 15 years and may not have permitted us to fully understand the long-term risk of donation; however, our lifetime risk estimates enable inferences generalizable to individuals of all ages irrespective of the number of years after donation.
Conclusion
Compared with a matched cohort of healthy nondonors, kidney donors had an increased risk of ESRD; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
—————————————————
What is the level of evidence provided by this article?
(case controlled study ) level 3
Why the conclusion of this study is different from the article above (article 1)?
1- in article 1 , the period from 1963 through 2007 (long duration) , sample size 3698 kidney donors (too small)
2- in article 2, the period from April 1994 and November 2011 , sample size 96 217 kidney donors
Please summarise this article in your own words
-It is acohort of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD, which was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant, whichever was identified first.
– Maximum follow-up was 15.0 years; median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy nondonors.
– 23 white, 33 Hispanic, and 75 black donors per 10 000 developed ESRD after kidney donation; because they donated a kidney, whereas the remaining cases resulted from the inherent risk of ESRD.
-Kidney donors had a somewhat higher estimated risk of developing ESRD throughout their lifetimes (90 per 10 000) than similarly healthy individuals who did not donate , but still a much lower risk than the general population.
-The primary strengths of this study the large sample size and the inclusion of an unscreened nondonor population demographically matched to the donor population.
What is the level of evidence provided by this article?
Level 2
Why the conclusion of this study is different from the article above (article 1)?
Because this study has large sample size and the inclusion of an unscreened nondonor population demographically matched to the donor population.
Objectives:
*To compare the risk of ESRD in kidney donors with a healthy cohort non donors and equally low risk of renal disease and free of contraindications to live donation and to stratify these comparisons by patient demographics.
Design, Settings, and Participants
*A cohort of 96 217 kidney donors in the US between April 1994 and November 2011 and a cohort of 20 024 participants of the (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD.
*Maximum follow-up was 15.0 years; median follow-up was 7.6 years ( 3.9-11.5 years) for kidney donors and 15.0 years for matched healthy non donors.
Results:
*Among live donors, with median follow-up of 7.6 years, ESRD developed in 99 individuals in a mean of 8.6 (3.6) years after donation.
* Among matched healthy non donors, with median follow-up of 15.0 years, ESRD developed in 36 non donors in 10.7 years.
*Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 in kidney donors and 3.9 per 10 000 in their matched healthy nondonor counterparts (P < .001).
*This difference was observed in both black and white individuals, with an estimated risk of 74.7 per 10 000 black donors vs 23.9 per 10 000 black non donors.
* Estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened non donors, and 14 per 10 000 healthy non donors.
The strength of study:
*The inclusion of every kidney donor in the United States over nearly 2 decades
*The highly reliable linkage-based ESRD ascertainment.
*The comparison with a healthy non donor cohort matched on a wide range of demographic and clinical variables.
*The large sample size of study populations,
*The inclusion of an unscreened non donor population demographically matched to the donor population.
The limitations of this study:
*The inferences were based on 2 cohorts of healthy individuals from the United States and may generalize imperfectly to donors in other countries.
*The donors are meticulously screened, and it is possible that the donors were healthier than the healthy non donors, even after screening by NHANES history, physical, and laboratory testing.
*The follow-up was limited to 15 years and may not have permitted us to fully understand the long-term risk of donation, however, lifetime risk estimates enable inferences generalizable to individuals of all ages irrespective of the number of years after donation.
Conclusions and Relevance:
Compared with matched healthy non donors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase was small. These findings may help inform discussions with persons considering live kidney donation.
*What is the level of evidence provided by this article?
Level 2 evidence observational cohort study with control.
*Why the conclusion of this study is different from the article above (article 1)?
Article ( 1) the sample size is small ( 3698) kidney donors who donated kidneys during the period from 1963 through 2007, long duration and the control group is general population.
Article ( 2 ) the sample size is large (96 217) live donors, and from April 1, 1994, and November 30, 2011 short duration.
An article recently published in NEJM has shown no additional risk of donation when compared with general population however the biggest criticism was that we cannot compare donors who are thoroughly investigated and in best of health with general population.
This article has tried to answer the question that are kidney donors at increased risk of ESRD following donation but the comparative group was similarly screened healthy non donors. This would more properly estimate the sequelae of kidney donation.
A cohort of 96 217 kidney donors in the United States between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD,
ESRD was defined as
the initiation of maintenance dialysis,
placement on the waiting list,
or receipt of a living or deceased donor kidney transplant, whichever was identified first.
Maximum follow-up was 15.0 years;
median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy nondonors.
Among live donors, with median follow-up of 7.6 years (maximum, 15.0), ESRD developed in 99 individuals in a mean (SD) of 8.6 (3.6) years after donation.
Among matched healthy nondonors, with median follow-up of 15.0 years (maximum, 15.0), ESRD developed in 36 nondonors in 10.7 (3.2) years,
Estimated risk of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in kidney donors
and 3.9 per 10 000 (95% CI, 0.8-8.9) in their matched healthy nondonor counterparts (P < .001)
This difference was observed in both black and white individuals.
This study concluded by saying that Compared with matched healthy nondonors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk increase was small.
Duration of follow Up
In Article1 was 4 yrs
Sample size was 3698 kidney donors
In Article 2.median follow-up of 7.6 years (maximum, 15.0)
A cohort of 96 217 kidney donors in the United States was sample size
Q1: Researchers compare the risk of ESKD in donors with the healthy general population who have no contraindications to live donation. ESKD was considered as initiation of dialysis, kidney transplantation (living or deceased) or being on the waiting list.
Incidence and lifetime risk of ESKD was determined among 96217 kidney donors in the NHANES III survey with a median follow-up of 7-6 years for donors and 15 years for matched healthy people. ESKD was seen in 99 donors and 36 healthy individuals. Estimated risk was 30.8 per 10000 in donors for ESKD and 3.9 per 10000 in matched healthy people. Estimated risk was 74.7 per 10000 in black donors vs 22.7 per 10000 white donors. In addition, B lifetime risk of ESKD was 90 per 10000 donors, 326 per 10000 not-screened and 14 per 10000 healthy individuals. Hence, kidney donors had a small increased risk of ESKD.
Q2: This study was a cohort study with level of evidence of 20.
Q3: The conclusion between two studies in different. This is caused by the difference between control
Summary
Risk of end stage renal disease following live kidney donation
This study highlights the importance of comparing risk of ESRD between kidney donors and those who have similar health parameters rather than using the general population as control.
The study found a strong link between incidence of ESRD and kidney donation. A wide variety of kidney donors have been included in this study to make a fair comparison and to give the results a better accuracy. The kidney donors were compared against a group of healthy non donors. Even rare events linked with certain ethnic groups have been identified due to a big sample size. A large number of medical conditions were screened for, and the study clearly links kidney donation with an increased risk of ESRD.
Level of evidence
case control study – level of evidence 3
Conclusion differences between article 1 and 2
The conclusion of this article is that kidney donors have a significant risk of ESRD over a period of 10 years post donation, compared to the life time risk of ESRD in healthy non donors.
The conclusion of the previous article is that ESRD risk is similar in both kidney donors and general population.
The difference in the concluding remarks of these 2 articles is due majorly to the fact that the given article has chosen healthy non donors as control, while article 1 has chosen general population as control. This led to a skewing of the results in article 1 because the general population is highly varied, and can include people who have worse health conditions than kidney donors. Thus with this comparison, it is unfair and inaccurate to conclude that kidney donors have similar risk as general population. This gives an impression that there is no health consequence to kidney donation. However, article 2 identifies correctly that this is not true, and that there is significant associated risk of kidney disease for kidney donors, where a few even land up in transplant waiting lists in the long term.
1- in article 1 , the period from 1963 through 2007 (long duration) , sample size 3698 kidney donors (too small)
2- in article 2, the period from April 1994 and November 2011 , sample size 96 217 kidney donors
Risk of End-Stage Renal Disease Following Live Kidney Donation
Summary of the article
This is a cohort study of 96 217 kidney donors in USA between April 1994 and November 2011 and a cohort of 20 024 participants of the NHANES III. Both were linked to Centers for Medicare & Medicaid Services data to ascertain development of ESRD. The maximum follow-up was 15.0 years; median follow-up was 7.6 years.
The previous studies compared the kidney donors to the general population regarding the risks of donation. The general population are not an ideal comparator, as it represents an unscreened and high- risk comparator.
Study Result and Conclusion
1. Of note; 25.2% were obese (BMI>30), 9.0% had a systolic blood pressure greater than 140 mm Hg and 24.2% smoked cigarettes at the time of donation.
2. Live donors had a higher estimated risk of ESRD than healthy nondonors across all ages.
3. Live donors had much lower estimated lifetime risk of ESRD than did the general population by age 80 years.
4. The study findings reaffirm the prevailing belief that lifetime risk of ESRD in live donors is no higher than in the general demographics-matched US population.
strengths of the study
a) The inclusion of every kidney donor in the United States over nearly 2 decades.
b) The highly reliable linkage-based ESRD ascertainment.
c) The comparison with a healthy nondonor cohort matched on a wide range of demographic and clinical variables.
d) The inclusion of an unscreened nondonor population demographically matched to the donor population.
e) The large sample size of this study populations, helped to estimate the incidence of a relatively rare event and to make inferences specific to race/ethnicity subgroups, providing critical information.
f) The lifetime risk estimates of the study, enable inferences generalizable to individuals of all ages irrespective of the number of years after donation.
g) The study screened for more than 30 medical conditions, thereby attenuating the possibility that the increased rates of ESRD in donors were attributable to secular trends rather than to donation.
Limitations of the Study
a) The study inferences were based on 2 cohorts of healthy individuals from the United States and may generalize imperfectly to donors in other countries.
b) Donors are meticulously screened, and it is possible that the donors were healthier than the healthy nondonors.
c) The follow-up was limited to 15 years and may not have permitted to fully understand the long-term risk of donation.
d) The kidney donors between 1994-2011 were compared to matched non-donors entered NHANRES III between 1988-1994. Putting in mind the increasing incidence of ESRD in the last 2 decades.
e) The secular trends in the general population were mediated by conditions such as morbid obesity, diabetes, and hypertension. These conditions have increased substantially over the last 2 decades in the general population, but much less so in carefully screened donors.
What is the level of evidence provided by this article?
This is a cohort study
Level of evidence II
Why the conclusion of this study is different from the article above (article 1)?
Article 1 Conclusion: Survival and risk of ESRD are similar between donors and the general population.
Article 2 Conclusion: Live donors had much lower estimated lifetime risk of ESRD than did the general population by age 80 years.
The difference between the 2 conclusions may be referred to:
A. In article 1:
i. The study included only a small proportion of all kidney donors.
ii. The analysis is subject to both response and survival bias (a rate of one of seven selected donors).
iii. Most of the living donors were white, which may limit the generalizability of the results.
iv. The used MDRD formula is not useful when the GFR is > 60( the formula was developed for those with GFR <60).
B. In article 2:
i. The study included every kidney donor in the United States over nearly 2 decades.
ii. The large sample size of this study populations, helped to estimate the incidence of a relatively rare event and to make inferences specific to race/ethnicity subgroups, providing critical information.
iii. The lifetime risk estimates of the study, enable inferences generalizable to individuals of all ages irrespective of the number of years after donation.
iv. The study screened for more than 30 medical conditions, thereby attenuating the possibility that the increased rates of ESRD in donors were attributable to secular trends rather than to donation.
Aim of the study: To compare the risk of ESRD in kidney donors with that of healthy persons who have no contraindications to donation.
Methods:
96 217 kidney donors in the United States between April 1994 and November 2011.
20 024 participants of the Third National Health and Nutrition Examination Survey.
The maximum follow-up was 15.0 years;
Median follow-up was 7.6 years for kidney donors and 15.0 years for matched healthy non-donors.
Outcomes: Cumulative incidence and lifetime risk of ESRD
Results:
Among live donors, with a median follow-up of 7.6 years, ESRD developed in 99 individuals in a mean of 8.6 years after donation.
Among matched healthy non-donors, with a median follow-up of 15.0 years, ESRD developed in 36 non-donors in 10.7 years.
The estimated risk of ESRD 15 years after the donation was 30.8 per 10 000 in kidney donors and 3.9 per 10 000 in their matched healthy non-donor counterparts.
This difference was observed in both black and white individuals.
The estimated lifetime risk of ESRD was 90 per 10 000 donors, 326 per 10 000 unscreened nondonors (general population), and 14 per 10 000 healthy non-donors.
Conclusion:
Compared with matched healthy non-donors, kidney donors had an increased risk of ESRD over a median of 7.6 years; however, the magnitude of the absolute risk was small.
Level 3 (case-control study).
This study found that live donors are at increased risk of ESRD, although the risk is small, while the previous study showed that live kidney donors are not at increased risk of ESRD; the main difference is in the control group, the previous study used the general population as a control group while this study selected healthy people who have no contraindications for donation.
Kidney transplantation provides recipients with better survival and better quality of life, Potential kidney donors should be informed and counseled about known risks of donation.
Studies showed that donation is not associated with increased risk of ESRD, however these studies compared carefully screened healthy donors with unscreened general population who may be ineligible for donation with higher risk for ESRD.
This study aims to compare the incidence of ESRD in live donors with healthy nondonors.
It included 96217 adult live donors and compared them with matched nondonors who were screened in NHANES III participants with exclusion of those with contraindication to kidney donation.
The study showed that kidney donors have an increased risk of ESRD when compared to nondonor healthy individuals and low risk when compared to general population.
In previous studies, kidney donation wasn’t associated with ESRD but in this study there were significant association in each race group.
Strengths:
Large sample size with inclusion of all donors in US over 2 decades.
Large number of donors allowed estimation of the incidence of rare events and to categorize them according to racial subgroups providing critical information for both donors and potential donors
Matched live donors and healthy nondonors according to several demographic and clinical variables.
Depended on highly reliable linkage based ESRD ascertainment.
Limitations:
Donors and controls were from US so generalization of of the results in other countries could be limited.
Donors were carefully screened and they might be healthier than healthy nondonors despite screening in NHANES
The follow up duration was 15 years so couldn’t determine the long term risk of donation, however it was enough to determine the risk of ESRD in donors.
Level of evidence: 2 (Cohort study)
The results were different because this study compared kidney donors to screened healthy population with no comorbidities that may contraindicate donation, larger number of donors over longer period of time (2 decades) and longer follow up time (15 years)
It included donors from several centers in US and with different ethnicities so allowed categorization of donors into racial subgroups.
The other study compared donors to unscreened general population, included small sample size of only white donors from single center.
INTRODUCTION
Thousands of healthy adults accept donor nephrectomy associated risks in view of willingness to support family members, friends, etc. and improve their quality of life.
But what will be the sequelae of donating one kidney and living with single kidney for rest of life is not well characterized.
Previous studies have done comparisons of donors with the general
population but, the general population is unscreened and there is an inherent high risk of ESRD than screened donors. This makes estimation of long term post donation sequalae difficult.
So this study was conducted to better understand the long term risk of ESRD post donation by comparing the incidence of ESRD in live donors with their healthy nondonor counterparts.
METHODS
Donors:
96217 kidney donors in the United States between April 1994 and November 2011 were included in the study.
Outcomes were ascertained by linkage to the Centers for Medicare & Medicaid Services’ (CMS’s) medical evidence Form 2728 (certification of ESRD), the transplant network’s kidney waiting list transplant databases
ESRD definition in the study:
(Whichever is the first)
Matched nondonors:
20024 participants of the Third National Health and Nutrition Examination Survey (NHANES III) were included in the study.
Medical information was obtained from patient self-report, physical examination, and radiologic and laboratory test results.
STATISTICAL ANALYSIS
Kaplan-Meier methods were used to estimate cumulative incidence of ESRD, with a time scale of years since study entry. Whereas, to estimate lifetime risk of ESRD, with a time scale of age in years and left truncation of age prior to study entry.
The P values were estimated using bootstrap methods to account for resampling of participants in the nondonor population
All analyses were performed using Stata 12.0/MP for Linux (Stata Corp).
RESULTS
Estimated cumulative incidence of ESRD at 15 years after donation was 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors.
Absolute risk was highest among black and hispanic donors.
The estimated risk of ESRD was higher in live donors compared to healthy nondonors across all ages and this risk increased with age in donors with 5 per 10000 if donation was around 30 years to 90 per 10000 if donation was around 80 years.
DISCUSSION
kidney donors had a relatively higher estimated risk of developing ESRD throughout their lifetimes (90 per 10 000) than healthy individuals who did not donate (14 per 10 000), but still a much lower risk than the general population (326 per 10 000).
STRENGTHS
LIMITATIONS
CONCLUSION
In comparison to healthy nondonors, kidney donors had an increased risk of ESRD. But the amount of the increase in the absolute risk was less
Introduction
Kidney transplantation remained the best option for patients with ESRD with better patients and graft survival and better quality of life and over years there is increased rate of living donations. Many studies addressed the perioperative donor nephrectomy risk which was trivial with very rare risk of perioperative death and consequent survival rate was similar to the general population. However, the long-term donor risk including life time risk of ESKD still not well documented as most of previous studies suggest that live donors do not have increased risk of end-stage renal disease (ESRD) compared with the general population; however, the general population could include unhealthy unscreened individuals than carefully screened donors also Limited by small sample sizes and lack of a healthy comparison group, and short follow up time. The aim of this study was to recognize the risk of ESRD following live donation by comparing the prevalence of ESRD in live donors with their healthy nondonor matching control group.
Main Outcomes and Measures
Collective incidence and lifetime risk of ESRD.
Methods
Selection of the donors from national registry data of OPTN records, all adult live donors between April 1, 1994, and November 30, 2011, were included in this study. End stage renal disease outcomes were determined by link to the Centers for Medicare & Medicaid Services’ (CMS’s) medical evidence Form 2728 (certification of ESRD). End-stage renal disease was defined as the initiation of maintenance dialysis, placement on the waiting list, or receipt of a living or deceased donor kidney transplant, any was identified first.
Selection criteria for the nondonor control population from the Third National and Nutrition Health institution service and examination
Survey (NHANES III). Matching was based on age, sex, self-identified race, educational background, body mass index (BMI), smoking history, and systolic BP, Total of 96 217 kidney donors between April 1994 and November 2011 and a cohort of 20 024 participants of the Third National Health and Nutrition Examination Survey (NHANES III, they exclude those with contraindication to donation which indicate they well -match to the living donor with low health risk.
Median follow up of 7.6 years ( maximum 15 years ).
Cumulative incidence of ESRD calculation
Kaplan-Meier methods were used to estimate cumulative incidence of ESRD, with a time scale of years since study entry (time of donation for donors, and enrollment into NHANES for nondonors).
Estimated Lifetime Risk of ESRD
Kaplan-Meier methods were used to estimate lifetime risk of ESRD, with a time scale of age in years and left truncation of age prior to study entry. Lifetime risk was estimated for 3 populations: live donors; matched healthy nondonors; and demographically matched unscreened nondonors (general population).
Absolute Risk Increase
Refer to the difference on the cumulative incidence between the two group (donor nephrectomy and nondonor control group).
Results
1.Estimated cumulative incidence of ESRD at 15 years after donation was significantly higher 30.8 per 10 000 (95% CI, 24.3-38.5) in donors and 3.9 per 10 000 (95% CI, 0.8-8.9) in healthy nondonors (P < .001).
2. Absolute risk of ESRD was highest among both black donors followed by Hispanic donors and lowest risk was in white donors
3. cumulative incidence of ESRD per 10 000 at 15 years varied significantly by age, race, sex and was significantly higher in black race, men than women.
4.ESRD developed in 17 individuals among the 9364 individuals in the nondonor pool, resulting in 36 ESRD events in matched nondonors in a mean (SD) of 10.7 (3.2) years after enrollment and median fu up of 15 years
5.The difference in ESRD incidence per 10 000 at 15 years between biologically related and unrelated donors was not statistically significant.
6. Live donors had a higher estimated lifetime risk of ESRD than healthy nondonors across all ages, and the older the donor the higher the risk
absolute risk increases of 76 per 10 000.however live donors had much lower estimated lifetime risk of ESRD than did the general population by age 80 years.
Strength of the study
1.Large sample size, diverse population including white, black Hispanic race (we can generalize the results)
2.Well-matched cohort of healthy nondonor control group for wide-range of clinical and demographic variables.
3.inclusion of an unscreened nondonor population demographically matched to the donor population.
Limitation of the study
1.National study from one country, US population however they are diverse population.
2. cohorts of healthy individuals from the United States and may specify incorrectly to donors in other countries.
3. donors are accurately screened; with opportunity they were healthier than the healthy nondonors control group.
4.follow up time of 15 years still may be not long enough for estimation of ESRD as hard long outcome
5. donors in this study donated between 1994-2011, whereas the nondonors to whom they were matched entered NHANES III between 1988-1994. With increasing incidence of ESRD over the last 2 decades whether this can be masked by factual trend in increased risk of ESRD due to increased obesity Hypertension and diabetes in general population.
Conclusion
In this large cohort study with median follow up of more than 7 years they conclude that kidney donors had an increased risk of ESRD; however, the degree of the absolute risk increase was trivial compared to matched non-donor control population . Such findings may help enlighten consultations with individuals’ assessment for live kidney donation.
What is the level of evidence provided by this article?
National cohort study with control group Level 3 of evidence
Why the conclusion of this study is different from the article above (article 1)?
As per reports from previous studies there were no association between donor nephrectomy and risk of ESRD While in this cohort study Such association was strong and was statistically significant within each race/ethnicity level , this can be explained by the well designed cohort includes national data base over 2 decades with large sample size from different centers, different ethnicity and well-matched healthier nondonor control group (not from general population) with longer follow -up period so the conclusion of this study should be taken in consideration and can change my practice in term of careful selection of donors considering the ethnic back ground , gender and age at time of donation .
That is an excellent reply, Dr Saja.
However, I would say it is level 2 evidence since this is an observational cohort study with controls.
thank you prof Ajay