Risks of Benzodiazepines in Chronic Obstructive Pulmonary Disease with Comorbid Posttraumatic Stress Disorder

RATIONALE: Benzodiazepines are associated with mortality and poor outcomes among patients with chronic obstructive pulmonary disease (COPD), but use of benzodiazepines for dyspnea among patients with end-stage disease may confound this relationship. OBJECTIVES: Assess the mortality risks of long-term benzodiazepine exposure among patients with COPD and comorbid post-traumatic stress disorder (PTSD), patients with chronic nonrespiratory indications for benzodiazepines. METHODS: We identified all patients with COPD and PTSD within the Veteran's Health Administration between 2010 and 2012. We calculated propensity scores for benzodiazepine use and compared overall and cause-specific mortality of patients with long-term (≥90 d) benzodiazepine use relative to matched patients without use. Secondary analyses assessed propensity-adjusted survival by characteristics of benzodiazepine exposure. RESULTS: Among 44,555 eligible patients with COPD and PTSD, 23.6% received benzodiazepines long term. In the matched sample of 19,552 patients, we observed no mortality difference (hazard ratio [HR] for long-term use, 1.06; 95% confidence interval [CI], 0.95-1.18) but greater risk of death by suicide among those with long-term use (HR, 2.33; 95% CI, 1.14-4.79). Among matched and unmatched patients, short-term benzodiazepine use, but not long-term use, was associated with increased mortality (short-term: HR, 1.16; 95% CI, 1.05-1.28; long-term: HR, 1.03; 95% CI, 0.94-1.13). CONCLUSIONS: Risks for respiratory compromise related to long-term benzodiazepine use in COPD may be less than previously estimated, but short-term use of benzodiazepines could still pose a mortality risk. Suicide associated with benzodiazepine use in this population warrants further investigation.