Sex and Cause-Specific Mortality among US Adults Receiving Maintenance Dialysis: National US Cohort Study 2000-2021

Abstract

Key Points: *Among incident dialysis patients, women are more likely to die from infections or withdrawal, whereas men are more likely to die from cardiovascular disease or cancer. *Young women (versus young men) are more likely to die from all causes, whereas older women (versus older men) are less likely to die from all causes. *Black women are more likely to die from all causes compared with Black men. Background: We examined sex differences in cause-specific mortality among men and women receiving maintenance dialysis and examined potential effect modification by age and race. Methods: We identified all adults aged 18 years or older initiating dialysis between 2000 and 2020 from the United States Renal Data System (N=2.16 million; 43.3% women). Cause-specific mortality (i.e., cardiovascular disease [CVD], withdrawal, infection, and cancer) was defined from the US Centers for Medicare and Medicaid Death Notification Form. All individuals were followed from dialysis start date until death date, transplant date, 10 years, or end of follow-up (December 31, 2021), whichever occurred first. Multivariable Cox proportional hazards models assessed the association between sex and 10-year cause-specific mortality, adjusting for demographic, clinical, and socioeconomic factors overall and stratified by age and race. Results: Overall, 832,259 men (67.9%) and 658,043 women (70.4%) died receiving maintenance dialysis with median survival times of 2.69 (interquartile range, 1.17–5.19) and 2.72 (interquartile range, 1.16–5.21) years, respectively. CVD was the leading cause of death (38.6% women and 40.2% men), followed by withdrawal (11.1% women and 9.6% men) and infections (9.8% women and 8.6% men). Overall, women had a 9% (adjusted hazard ratio, 1.09 [95% confidence interval, 1.08 to 1.11]) and 15% (1.15 [1.14 to 1.17]) higher likelihood of infection and withdrawal-related mortality compared with men, respectively. Conversely, women had a 7% (0.93 [0.92 to 0.94]) and 10% (0.90 [0.87 to 0.92]) lower likelihood of CVD and cancer-related mortality, respectively, compared with men. By age, younger women (versus men) aged 18–44 years had higher likelihood of excess mortality across all specific causes (including a 40% increased risk of withdrawal compared with men of the same age), whereas older women (versus men) older than 75 years had a lower likelihood. By race, non-Hispanic Black women (versus men) had higher mortality across all specific causes, but for all other races, sex differences were similar to the overall population. Conclusions: A sex-specific approach that incorporates intersectionality of both age and race in the management of complications among dialysis patients may be recommended to mitigate excess mortality risks.