Sex Disparity in Cause-Specific and All-Cause Mortality Among Incident Dialysis Patients

Early mortality rates of female patients on dialysis have been, at times, observed to be higher than rates among male patients. The differences in cause-specific mortality between male and female incident dialysis patients with kidney failure are not well understood and were the focus of this study.Retrospective cohort study.Participants: Incident patients who had initiated dialysis in Australia and New Zealand between 1998-2018.Sex.Cause-specific and all-cause mortality on dialysis, censored for kidney transplantation.Adjusted cause-specific proportional hazards models, focusing on the first 5 years following initiation of dialysis.Among 53,414 patients (20,876 [39%] of whom were female) followed for a median period of 2.8 (IQR 1.3-5.2) years, 27,137 (51%) died, with the predominant cause of death attributed to cardiovascular disease (CVD, 18%), followed by dialysis withdrawal (16%). Compared to male patients, female patients were more likely to die in the first 5 years after dialysis initiation (adjusted hazard ratio (aHR) of 1.06 [95% CI 1.03-1.09]). Even though female patients experienced a lower risk of CVD-related mortality (aHR 0.93 [0.89-0.98]) compared to male patients, they experienced a greater risk of infection-related (aHR 1.20 [1.10-1.32]) and dialysis withdrawal-related mortality (aHR 1.19 [1.13-1.26]).Possibility of residual and unmeasured confounders.Compared with male patients, female patients had a higher risk of all-cause mortality in the first 5 years post-dialysis initiation, a difference driven by higher mortality from infections and dialysis withdrawals. These findings may inform the study of sex differences in mortality in other geographic settings.