Health-related quality of life in kidney donors from the last five decades: results from the RELIVE study

Abstract

Live donation benefits recipients, but the long-term consequences for donors remain uncertain. Renal and Lung Living Donors Evaluation Study surveyed kidney donors (N = 2455; 61% women; mean age 58, aged 24-94; mean time from donation 17 years, range 5-48 years) using the Short Form-36 Health Survey (SF-36). The 95% confidence intervals for White and African-American donors included or exceeded SF-36 norms. Over 80% of donors reported average or above average health for their age and sex (p < 0.0001). Donors' age-sex adjusted physical component summary (PCS) scores declined by half a point each decade after donation (p = 0.0027); there was no decline in mental component summary (MCS) scores. White donors' PCS scores were three points higher (p = 0.0004) than non-Whites'; this difference remained constant over time. Nine percent of donors had impaired health (PCS or MCS score >1 SD below norm). Obesity, history of psychiatric difficulties and non-White race were risk factors for impaired physical health; history of psychiatric difficulties was a risk factor for impaired mental health. Education, older donation age and a first-degree relation to the recipient were protective factors. One percent reported that donation affected their health very negatively. Enhanced predonation evaluation and counseling may be warranted, along with ongoing monitoring for overweight donors.

Keywords: Kidney; kidney donor; living donor; organ donation; quality of life.

Figure 1. Enrollment Flow Diagram

This diagram describes how the sample of living organ donors who completed quality of life (QOL) questionnaires for this study (N=2,455) was derived from a comprehensive review of the medical records of all live donor kidney transplants conducted at three large clinical sites: University of Minnesota (UMN), The Mayo Clinic - Rochester, MN, and University of Alabama, Birmingham (UAB).

Figure 2. SF-36 profile of RELIVE donors

Boxplots display donor scores for all the scales in the SF-36 profile. Higher scores indicate better health states. All SF-36 scales are standardized to have a mean of 50 and standard deviation of 10 in the US general population. A dotted line indicates the population mean on the y-axis. Boxes extend from the 25th to 75th percentiles, whiskers (vertical lines) extend from the 1st to the 99th percentiles. Abbreviations: physical component summary score (PCS), mental component summary score (MCS), physical health (PH), impact of physical health on role functioning at home and at work (RP), bodily pain (BP), vitality (VT), general health perceptions (GH), social functioning (SF), impact of mental health on role functioning (RE), and mental health (MH).

Figure 3. SF-36 Profiles of RELIVE white and African-American donors

Mean unadjusted SF-36 scores of white and African-American donors are shown as bars. Race data were obtained by self-report. The horizontal solid line marks the population norm and dotted lines mark ± 0.5 SD (the range for average scores). White donors had higher scores for social functioning than African-American donors (p = 0.0007); other SF-36 scores were not significantly different at p=0.01. Mean (± 1 SE) scores for RELIVE donors and two comparison groups are presented below the chart. Results from the National Health Measurement Survey (NHMS), a representative telephone survey of US adults 35–89 years old conducted in 2005–2006 (17) are shown in the first line. RELIVE donors’ (all races combined) SF-36 scores were significantly higher than NHMS results for the PCS, role physical, bodily pain, general health perceptions, and social functioning (ps from 0.006 to <0.0001); scores for physical functioning, vitality, role emotional, and the MCS did not differ; and NHMS mental health results were higher than RELIVE donors’ scores (p <0.0001). Results from the African-American Health project (AAHP), a population-based, in-home survey of 998 African-American adults aged 49 to 65 living in Missouri conducted 2000–2001 (18), are shown in the bottom line beneath the chart. SF-36 overall and domain scores of African-American donors and AAHP participants were not significantly different, except for general health perceptions, where African-American donors reported higher scores (p < 0.0001).

Figure 4. Sex- and age-adjusted PCS and MCS scores of RELIVE donors by time from donor surgery

Each donor’s sex- and age-adjusted physical and mental component summary score is plotted by time from donor surgery in years in this scatterplot. Data points above the norm mean (50) on the y-axis indicate donors with better health and functioning than peers of the same age and sex. The solid line is a loess curve fitted to the observed median score and the dotted lines follow the 5th and 95th percentiles at each point in time. The overall adjusted physical and mental component mean scores are 54±9 (range 13 to 78) and 52±9 (range 3 to 71), respectively.

Figure 5. Proportions of donors reporting “excellent” or “very good” health, according to race and education and comparable data for US white and African-American adults

Bar heights indicate the proportion of donors reporting excellent or good health within four categories of educational attainment: less than high school, high school graduate, some college, or 4-year college graduate. Vertical lines atop the bars indicate ± 1 standard error. The last 8 bars are comparable data on self-reported health by educational attainment for US white and African-American adults aged 25–74 from the 2005–2007 Behavioral Risk Factor Surveillance Systems as reported by Braveman et al (24). Standard errors are not provided for the US population estimates because they have been weighted to reflect the entire population. Sixteen donors with missing values for education or self-rated health status were omitted. After adjustment for education, white donors were more likely to report excellent or very good health than either African-American donors or donors of other races (p = 0.0034 and p = 0.0004, respectively). Overall, patterns of self-rated health status are similar for donors and US adults.