Racial and Sex Differences in Postoperative Mortality Between Patients With Versus Without Dementia

To compare racial-sex differences in postoperative mortality by dementia status.

Because patients with dementia often find it harder to advocate for themselves, racial-sex differences in postoperative mortality may be greater for patients with dementia versus without dementia.

Among Medicare fee-for-service beneficiaries aged 65 to 99 years who underwent one of 12 common surgical procedures in 2016 to 2019, we compared 30-day postoperative mortality (death during the index hospitalization or within 30 days of surgery) across 4 race-sex groups (Black men [reference group], White men, White women, and Black women) stratified by dementia status. Elective and nonelective surgeries were examined separately.

Among 888,391 patients undergoing elective surgery, 65,450 (7.4%) had dementia. Postoperative mortality was highest among Black men, both with dementia (adjusted mortality, 3.99%) and without dementia (2.11%). Racial-sex differences were generally greater among patients with dementia. For example, the mortality difference between White women versus Black men was significantly larger among patients with dementia (adjusted difference, -2.38 percentage points [pp]; 95% confidence interval [CI], -3.34 to -1.41) than among those without dementia (-0.75 pp; 95% CI, -0.96 to -0.54) (P-for-interaction = 0.001). In contrast, among 394,554 patients undergoing nonelective surgery, 56,273 (14.3%) had dementia, and we found no evidence that mortality was highest among Black men or that racial-sex differences meaningfully varied by dementia status.

Among patients undergoing elective surgery, racial-sex differences in postoperative mortality were greater among patients with dementia than among those without dementia, highlighting the need for targeted strategies to ensure consistent surgical care.