DEcIDE Research: No Association Between Antidepressant Use and Pneumonia

Pneumonia is a major cause of morbidity and mortality in the elderly. Together with influenza, pneumonia constitutes the fifth-leading cause of death in those age 65 years and older in the United States.

A recent study undertaken to identify possible signals of iatrogenic illness in the elderly found that hospitalization for aspiration pneumonia was three times as likely to occur in the 90-day period following a hospitalization for depression; this led to the hypothesis that antidepressant drugs may increase the risk of aspiration pneumonia. If true, it could have major therapeutic implications for the treatment of elderly depressed patients, since the benefit of pharmacotherapy would need to be weighed against the risk of aspiration pneumonia. However, this prior study did not measure exposure to antidepressants or attempt to control for patient factors that may change over time.

The EHC Program commissioned the University of Pennsylvania School of Medicine DEcIDE Center to evaluate the hypothesis that antidepressant use in the elderly is associated with hospitalization for pneumonia, or for aspiration pneumonia or pneumonitis.

Researchers identified 12,044 cases of hospitalization for pneumonia (the primary aim) and 48,176 controls. The odds ratio (OR) for any antidepressant use, adjusting for age, sex, and calendar year, was 1.61 (95% confidence interval 1.46 to 1.78). After further adjustment for comorbidity measures, the OR was 0.89 (0.79 to 1.00). The researchers also identified 159 cases of hospitalization for aspiration pneumonia (the secondary aim) and 636 controls. The OR for any antidepressant use, adjusted for age, sex and calendar year was 1.45 (0.65 to 3.24). After further adjustment for comorbidity measures, the OR was 0.63 (0.23 to 1.71).

Findings failed to confirm the hypothesis that use of antidepressants by elderly patients increases the risk of hospitalization for pneumonia or for aspiration pneumonia. Based on currently available evidence, decisions regarding the use of antidepressants in elderly persons should not be affected by concern about pneumonia risk.