Sex Differences in Mortality and Health Care Utilization After Dementia Diagnosis

Importance Sex differences may contribute to disparities in dementia outcomes. Objective To understand the association between sex and mortality and health care services use after dementia diagnosis. Design, Setting, and Participants This nationwide cohort study used Medicare enrollment data and took place from 2014 to 2021 with up to 8 years of follow-up. Analysis was performed from April 2024 to April 2025. This study included 5 721 711 patients 65 years or older with International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes for dementia with at least 1 year of prior fee-for-service Medicare enrollment. Exposures Sex, determined from Medicare enrollment data, derived from Social Security Administration records. Main Outcomes and Measures The primary outcome was hazard of all-cause mortality, estimated with Cox proportional hazard regression. Secondary outcomes included hazards of use of common health care services, such as all-cause hospitalizations, skilled nursing facility stays, receipt of neuroimaging services, and physical/occupational therapy. Results A total of 5 721 711 patients (3 302 579 female and 2 419 132 male) with incident dementia between 2014 and 2021 were included in the study. Female patients had lower crude 1-year mortality rates (21.8% vs 27.2% for male patients; P < .001) and lower rates of all-cause hospitalizations (46.9% vs 50.5%; P < .001). The unadjusted hazard of death associated with male sex was 1.30 (95% CI, 1.29-1.31; P < .001). After adjustment for age, race and ethnicity, Medicaid dual eligibility, medical comorbidity burden, and access to health care resources, the association was modestly attenuated (adjusted hazard ratio, 1.24; 95% CI, 1.23-1.26; P < .001). Similarly, the unadjusted hazard ratio of all-cause hospitalization associated with male sex was 1.13 (95% CI, 1.12-1.14; P < .001); the adjusted hazard ratio was 1.08 (95% CI, 1.08-1.09; P < .001). Male patients also had increased hazards of hospice stay, neuroimaging services, and hospitalization for neurodegenerative disease diagnosis or behavioral disturbance. Conclusions and Relevance In this study, male patients with dementia had higher mortality rates and higher use of many health care services, especially hospital stays, than comparable female patients. Strategies to slow mortality and decrease health care use among male patients with dementia may be particularly impactful in limiting the burden of dementia. Given higher incidence of dementia among women, a focus on efforts to prevent dementia is necessary to achieve population-level health equity in dementia-attributable mortality by sex.