Quality of medical care and excess mortality in older patients with mental disorders

Abstract

Background: This study investigated whether differences in quality of medical care might explain a portion of the excess mortality associated with mental disorders in the year after myocardial infarction.

Methods: This study examined a national cohort of 88 241 Medicare patients 65 years and older who were hospitalized for clinically confirmed acute myocardial infarction. Proportional hazard models compared the association between mental disorders and mortality before and after adjusting 5 established quality indicators: reperfusion, aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, and smoking cessation counseling. All models adjusted for eligibility for each procedure, demographic characteristics, cardiac risk factors and history, admission characteristics, left ventricular function, hospital characteristics, and regional factors.

Results: After adjusting for the potential confounding factors, presence of any mental disorder was associated with a 19% increase in 1-year risk of mortality (hazard ratios [HR], 1.19; 95% confidence interval [CI], 1.04-1.36). After adding the 5 quality measures to the model, the association was no longer significant (HR, 1.10; 95% CI, 0.96-1.26). Similarly, while schizophrenia (HR, 1.34; 95% CI, 1.01-1.67) and major affective disorders (HR, 1.11; 95% CI, 1.02-1.20) were each initially associated with increased mortality, after adding the quality variables, neither schizophrenia (HR, 1.23; 95% CI, 0.86-1.60) nor major affective disorder (HR, 1.05; 95% CI, 0.87-1.23) remained a significant predictor.

Conclusions: Deficits in quality of medical care seemed to explain a substantial portion of the excess mortality experienced by patients with mental disorders after myocardial infarction. The study suggests the potential importance of improving these patients' medical care as a step toward reducing their excess mortality.