Mortality risk for women on chronic hemodialysis differs by age

BACKGROUND: Previous reports have demonstrated similar survival for men and women on hemodialysis, despite women’s increased survival in the general population. OBJECTIVES: To examine the effect of age on mortality in women undergoing chronic hemodialysis. DESIGN: A retrospective cohort study using an administrative data registry, the Canadian Organ Replacement Registry (CORR) from Jan. 2001 and Dec. 2009. SETTING: Canada. PATIENTS: 28,971 (Women 11,792 (40.7%), Men 17,179 (59.3%)) incident chronic hemodialysis patients who survived greater than 90 days on dialysis. MEASUREMENTS: All-cause mortality. METHODS: Cox proportional hazards and competing risks models were employed to determine the independent association between sex, age and likelihood of all-cause mortality with renal transplantation as the competing outcome. RESULTS: During the study period, 6060 (51.4%) of women and 8650 (50.4%) of men initiating dialysis died. Younger women experienced higher mortality (Age < 45: Women 22.5%, Men 18.2%, hazard ratio (HR) 1.31 (1.12-1.52)) whereas elderly women experience lower mortality (Age 75–85: Women 65%, Men 67.3%, HR 0.94 95% CI 0.88-0.99, Age > 85: Women 66%, Men 70.2%, HR 0.83 95% CI 0.71-0.97) compared to men. This relationship persisted after accounting for the competing risk of transplantation. LIMITATIONS: The cause of death was unknown. CONCLUSIONS: Women’s survival on chronic hemodialysis varies by age compared to men with a significantly higher mortality in women younger than 45 years old and lower mortality in woman older than 75 years of age.