Multimorbidity, Depression, and Mortality in Primary Care: Randomized Clinical Trial of an Evidence-Based Depression Care Management Program on Mortality Risk

Abstract

Background: Two-thirds of older adults have two or more medical conditions that often take precedence over depression in primary care.

Objective: We evaluated whether evidence-based depression care management would improve the long-term mortality risk among older adults with increasing levels of medical comorbidity.

Design: Longitudinal analyses of the practice-randomized Prevention of Suicide in Primary Care Elderly: Collaborative Trial (PROSPECT). Twenty primary care practices randomized to intervention or usual care.

Patients: The sample included 1204 older primary care patients completing the Charlson Comorbidity Index (CCI) and other interview questions at baseline.

Intervention: For 2 years, a depression care manager worked with primary care physicians to provide algorithm-based care for depression, offering psychotherapy, increasing the antidepressant dose if indicated, and monitoring symptoms, medication adverse effects, and treatment adherence.

Main measures: Depression status based on clinical interview, CCI to evaluate medical comorbidity, and vital status at 8 years (National Death Index).

Key results: In the usual care condition, patients with the highest levels of medical comorbidity and depression were at increased risk of mortality over the course of the follow-up compared to depressed patients with minimal medical comorbidity [hazard ratio 3.02 (95% CI, 1.32 to 8.72)]. In contrast, in intervention practices, patients with the highest level of medical comorbidity and depression compared to depressed patients with minimal medical comorbidity were not at significantly increased risk [hazard ratio 1.73 (95% CI, 0.86 to 3.96)]. Nondepressed patients in intervention and usual care practices had similar mortality risk.

Conclusions: Depression management mitigated the combined effect of multimorbidity and depression on mortality. Depression management should be integral to optimal patient care, not a secondary focus.

Trial registration: ClinicalTrials.gov NCT00000367.

Fig. 1

Adjusted relative hazard of all-cause mortality. Relative hazard predicted using Cox proportional hazards regression for depressed (gray) and nondepressed (black) patients in intervention practices (solid) or usual care practices (dashed), adjusted for baseline age, sex, education, depression severity, cognition, and suicidal ideation. The curves show adjusted hazard ratios (HRs). A CCI of zero was used as the reference (HR = 1)