Diagnosed depression and sociodemographic factors as predictors of mortality in patients with dementia

Background Potentially modifiable risk factors for developing dementia have been identified. However, risk factors for increased mortality in patients with diagnosed dementia are not well understood. Identifying factors that influence prognosis would help clinicians plan care and address unmet needs. Aims To investigate diagnosed depression and sociodemographic factors as predictors of mortality in patients with dementia in UK secondary clinical care services. Method We conducted a cohort study of patients with a dementia diagnosis in an electronic health records database in a UK National Health Service mental health trust. Results In 3374 patients with 10 856 person-years of follow-up, comorbid depression was not associated with mortality (adjusted hazard ratio 0.94; 95% CI 0.71-1.24). Single patients had higher mortality than those who were married (adjusted hazard ratio 1.25; 95% CI 1.03-1.50). Patients of Asian ethnicity had lower mortality rates than White British patients (adjusted hazard ratio 0.50; 95% CI 0.34-0.73). Conclusions Clinically diagnosed depression does not increase mortality in patients with dementia. Patients who are single are a potential high-mortality risk group. Lower mortality rates in Asian patients with dementia that have been reported in the USA also apply in the UK.