Use of opioids or benzodiazepines and risk of pneumonia in older adults: a population-based case-control study.

OBJECTIVES: To examine whether use of opioids or benzodiazepines is associated with risk of community-acquired pneumonia in older adults.

DESIGN: Population-based case-control study.

SETTING: An integrated healthcare delivery system.

PARTICIPANTS: Community-dwelling, immunocompetent adults aged 65 to 94 from 2000 to 2003. Presumptive pneumonia cases were identified from health plan automated data and validated through medical record review. Two controls were selected for each case with pneumonia, matched on age, sex, and calendar year.

MEASUREMENTS: Information about opioid and benzodiazepine use came from computerized pharmacy data. Information on covariates including comorbid illnesses and functional and cognitive status came from medical record review and electronic health data.

RESULTS: One thousand thirty-nine validated cases of pneumonia and 2,022 matched controls were identified. One hundred forty-four (13.9%) cases and 161 (8.0%) controls used prescription opioids (adjusted odds ratio (OR) = 1.38, 95% confidence interval (CI) = 1.08-1.76 vs nonuse). Risk was highest for opioids categorized as immunosuppressive based on immunological studies (OR = 1.88, 95% CI = 1.26-1.79 vs nonuse), whereas for nonimmunosuppressive opioids the OR was 1.23 (95% CI = 0.89-1.69). Risk was highest in the first 14 days of use (OR = 3.24, 95% CI = 1.64-6.39 vs nonuse). For long-acting opioids, the OR was 3.43 (95% CI = 1.44-8.21) versus nonuse, whereas for short-acting opioids, it was 1.27 (95% CI = 0.98-1.64). No greater risk was seen for current benzodiazepine use compared to nonuse (OR = 1.08, 95% CI = 0.80-1.47).

CONCLUSION: Use of opioids but not benzodiazepines was associated with pneumonia risk. The differences in risk seen for different opioid regimens warrant further study.