New Coprescription of Opioids and Benzodiazepines and Mortality Among Veterans Affairs Patients With Posttraumatic Stress Disorder.

BACKGROUND

Opioids and benzodiazepines are commonly coprescribed medications. The mortality risk associated with their concurrent use is unknown.

OBJECTIVE

To estimate the all-cause mortality risk for patients newly prescribed opioids and benzodiazepines concurrently relative to patients prescribed benzodiazepines only, opioids only, or neither medication.

METHODS

This propensity score-matched, retrospective, cohort study included 17,476 patients receiving Veterans Affairs (VA) health care between October 1, 2009, and September 30, 2011, and diagnosed with posttraumatic stress disorder identified using ICD-9-CM code 309.81. One-year total and cause-specific mortality was assessed by hazard ratios and subhazard ratios, adjusted for propensity score, age, baseline psychiatric and medical comorbidity, and daily medication dose.

RESULTS

Concurrent users (n = 4,369) were propensity score matched 1:1 with benzodiazepine-only users, opioid-only users, and nonusers. One year after medication start, the concurrent cohort had higher rates of all-cause mortality (116 deaths) relative to benzodiazepine-only (75 deaths; adjusted hazard ratio = 1.52; 95% CI, 1.14-2.03), opioid-only (67 deaths; 1.76; 95% CI, 1.32-2.35), and nonuser (60 deaths; 1.85; 95% CI, 1.30-2.64) cohorts. Risk of overdose death was greater among patients in the concurrent cohort relative to patients in the benzodiazepine-only (adjusted subhazard ratio = 2.59; 95% CI, 1.00-6.66), opioid-only (2.58; 95% CI, 1.09-6.11), and nonuser (9.16; 95% CI, 2.27-37.02) cohorts. For circulatory disease-related deaths, the adjusted subhazard ratio for concurrent medication users was 1.81 (95% CI, 1.01-3.24) relative to nonusers.

CONCLUSIONS

New coprescription of opioids and benzodiazepines was associated with increased all-cause mortality and overdose death compared with new prescription of benzodiazepines only, opioids only, or neither medication and increased circulatory disease-related death relative to neither medication.