Effects of Functional Disability and Depressive Symptoms on Mortality in Older Mexican-American Adults with Diabetes Mellitus.

OBJECTIVES: To examine the effect of co-occurring depressive symptoms and functional disability on mortality in older Mexican-American adults with diabetes mellitus.

DESIGN: Longitudinal cohort study.

SETTING: Hispanic Established Populations for the Epidemiological Study of the Elderly (HEPESE) survey conducted in the southwestern United States (Texas, Colorado, Arizona, New Mexico, California).

PARTICIPANTS: Community-dwelling Mexican Americans with self-reported diabetes mellitus participating in the HEPESE survey (N = 624).

MEASUREMENTS: Functional disability was assessed using a modified version of the Katz activity of daily living scale. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Mortality was determined by examining death certificates and reports from relatives. Cox proportional hazards regression analyses were used to examine the hazard of mortality as a function of co-occurring depressive symptoms and functional disability.

RESULTS: Over a 9.2-year follow-up, 391 participants died. Co-occurring high depressive symptoms and functional disability increased the risk of mortality (hazard ratio (HR) = 3.02, 95% confidence interval (CI) = 2.11-4.34). Risk was greater in men (HR = 8.11, 95% CI = 4.34-16.31) than women (HR = 2.21, 95% CI = 1.42-3.43).

CONCLUSION: Co-occurring depressive symptoms and functional disability in older Mexican-American adults with diabetes mellitus increases mortality risk, especially in men. These findings have important implications for research, practice, and public health interventions.