Kidney-Failure Risk Projection for the Living Kidney-Donor Candidate

Abstract

Background: Evaluation of candidates to serve as living kidney donors relies on screening for individual risk factors for end-stage renal disease (ESRD). To support an empirical approach to donor selection, we developed a tool that simultaneously incorporates multiple health characteristics to estimate a person's probable long-term risk of ESRD if that person does not donate a kidney.

Methods: We used risk associations from a meta-analysis of seven general population cohorts, calibrated to the population-level incidence of ESRD and mortality in the United States, to project the estimated long-term incidence of ESRD among persons who do not donate a kidney, according to 10 demographic and health characteristics. We then compared 15-year projections with the observed risk among 52,998 living kidney donors in the United States.

Results: A total of 4,933,314 participants from seven cohorts were followed for a median of 4 to 16 years. For a 40-year-old person with health characteristics that were similar to those of age-matched kidney donors, the 15-year projections of the risk of ESRD in the absence of donation varied according to race and sex; the risk was 0.24% among black men, 0.15% among black women, 0.06% among white men, and 0.04% among white women. Risk projections were higher in the presence of a lower estimated glomerular filtration rate, higher albuminuria, hypertension, current or former smoking, diabetes, and obesity. In the model-based lifetime projections, the risk of ESRD was highest among persons in the youngest age group, particularly among young blacks. The 15-year observed risks after donation among kidney donors in the United States were 3.5 to 5.3 times as high as the projected risks in the absence of donation.

Conclusions: Multiple demographic and health characteristics may be used together to estimate the projected long-term risk of ESRD among living kidney-donor candidates and to inform acceptance criteria for kidney donors. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

Figure 1. 15-year (A) and lifetime (B) projections of ESRD incidence in the United States by age, race, and sex for the “base-case” scenario*

*The base-case scenario is the following: age-specific eGFR (114, 106, 98, 90, 82, 74, and 66 ml/min/1.73 m² for ages 20, 30, 40, 50, 60, 70, and 80 years, respectively), systolic blood pressure 120 mmHg, urine albumin-creatinine ratio (ACR) 4 mg/g (0.4 mg/mmol), BMI 26 kg/m², and no diabetes mellitus or anti-hypertensive medication use. These were selected as being representative of recent US living kidney donors. Lifetime projections are based on 15 years of follow-up data and calibrated to the incidence of ESRD in the US low-risk population, and thus lack precision. All estimates reflect the United States population average for latent characteristics; individual risk may be higher or lower. Confidence intervals for each of the estimates are depicted in Appendix 4. Confidence intervals were obtained from simulations sampled from the distribution of meta-analyzed hazard ratios.