The risk of death within 90 days after living kidney donation has declined to less than 1 in 10,000 in recent years, a significant reduction compared with the risk of death observed in previous decades, according to a recent study.
In the national registry study, published in JAMA, investigators used data from the Scientific Registry of Transplant Recipients involving 164,593 living kidney donors from 1993 to 2022.
The overall 90-day mortality rate was 2.2 per 10,000 donations over the 30-year study period, with 36 total deaths. Mortality dropped from 3.0 per 10,000 donations (95% confidence interval [CI] = 1.6–5.1) from 1993 to 2002 and 2.9 per 10,000 (95% CI = 1.7–4.6) from 2003 to 2012 to 0.9 per 10,000 (95% CI = 0.3–2.0) from 2013 to 2022 (P = .01). There were 13 deaths between 1993 and 2002, 18 deaths between 2003 and 2012, and 5 deaths between 2013 and 2022.
Among 141,218 donors from 1999 to 2022, mortality was higher with open vs laparoscopic nephrectomy (4.3 vs 1.9 per 10,000); however, the difference was not statistically significant (P = .08). Male donors had a fourfold higher 90-day mortality risk compared with female donors (4.0 vs 1.0 per 10,000, P < .001). Mortality was 4.2 per 10,000 among Black donors, 2.0 per 10,000 among White donors, and 1.3 per 10,000 among donors of other races, but these differences were not statistically significant (P = .12). Among 110,973 donors from 2004 to 2022, those with predonation hypertension had significantly higher mortality compared with nonhypertensive donors (7.5 vs 1.4 per 10,000, P = .03). There were no statistically significant differences by age, ethnicity, or body mass index.
When data on the cause of death was available (19 of 28 deaths since 2000), hemorrhage was the most common cause, accounting for 8 deaths. Other reported causes included infection (n = 2), pulmonary embolism (n = 2), cardiovascular events (n = 2), cerebrovascular accident (n = 1), homicide (n = 1), and other unspecified reasons (n = 3).
Death events were captured from Organ Procurement and Transplantation Network (OPTN) living donor follow-up, the National Technical Information Service Death Master File, and deaths reported to the OPTN through interagency data sharing. Per OPTN policy, donor deaths within 2 years had to be reported within 72 hours of the hospital becoming aware.
The investigators acknowledged that the small number of deaths limited their ability to estimate relative risks across donor subgroups. Additionally, incomplete follow-up may have biased mortality estimates, although this would likely have resulted in underestimation of risk in earlier eras caused by less stringent reporting requirements in the past.
Conflict of interest disclosures can be found in the study.