Outcomes and motivations in unspecified (nondirected altruistic) kidney donation: Results from a United Kingdom prospective cohort study.

Unspecified kidney donors (UKDs) increase the number of high-quality kidneys available for transplantation. This study aimed to determine whether the practice was acceptable, based on the noninferiority of donor physical and psychosocial outcomes when compared to specified kidney donors (SKDs). This longitudinal, prospective cohort study investigated potential living kidney donors from across all 23 UK adult kidney transplant centers. Participants completed validated questionnaires at 4 time points (recruitment, 2-4 weeks predonation, 3- and 12-months postdonation). Clinical outcome data were collected from National Health Service Blood and Transplant. Three hundred seventy-three (of 837 recruited; 45.7%) went on to donate (November 2016 to January 2021). There were no differences in donation rates (204 SKDs [54.7%] vs 169 UKDs [45.3%]; P = .944). Both groups reported being motivated by the desire to help someone (P = .157). Tests for noninferiority indicated that UKDs do no worse than SKDs on psychosocial or clinical outcomes over 12 months, and costs are similar (P > .05). This is the world's largest prospective observational study comparing SKDs and UKDs. It demonstrates no differences in primary motivation, donation rates, regret, cost, or psychosocial and physical outcomes. These data should reassure transplant professionals and potential donors and can bolster confidence in the practice around the world.