Model calculates lifetime ESRD risk from predonation characteristics

A new online risk calculator can assess 15-year and lifetime risk of ESRD among potential living kidney donors, reports a study in The New England Journal of Medicine.

The researchers performed a meta-analysis of seven general population cohorts, totaling more than 4.9 million participants. Included subjects were free of absolute contraindications to kidney donation; median follow-up was 4 to 16 years. Models were developed to estimate the combined effects of 10 readily available demographic and clinical variables for estimating ESRD risk among kidney and donor candidates over a 15-year time window. The 15-year projections were compared with actual risk in a population of 53,000 living kidney donors.

Risk of ESRD was significantly associated with estimated GFR (eGFR), noninsulin-dependent diabetes, higher systolic BP, antihypertensive medication use, current and former smoking, and higher urinary-to-albumin creatinine ratio. There was also a small, graded association with obesity. Fifteen-year risk varied by age and race: for a 40-year-old with health variables similar to those of age-matched kidney donors, risk was 0.24 percent for black men, 0.15 percent for black women, 0.06 percent for white men, and 0.04 percent for white women.

Lifetime projected ESRD risks were highest in the youngest age group, particularly among young blacks. In contrast, many older individuals were at lower risk—even in the presence of health issues regarded as contraindications to donation. On analysis of observed 15-year ESRD rates among living kidney donors, postdonation risks were 3.5 to 5.3 times higher than predonation risks.

As an aid to evaluating and counseling potential donors, Grams et al. (1) developed an online risk tool (http://transplantmodels.com/esrdrisk/). They note that the magnitude of the additional risk after living kidney donation and the variations in risk associated with health characteristics remain unclear [Grams ME, et al. Kidney-failure risk projection for the living kidney-donor candidate. N Engl J Med 2016; 374:411–421].