Background: The Centers for Disease Control and Prevention recognizes Medicaid as a high-risk population for fatal opioid overdose. Further research is needed to identify factors that put Medicaid patients at increased risk.
Objective: To determine whether patterns of opioid use are associated with risk of opioid-related mortality among opioid users.
Design: This is a retrospective cohort study.
Patients: In total, 150,821 noncancer pain patients aged 18-64 years with ≥1 opioid prescription, April 2006 to December 2010, Washington Medicaid.
Measures: Average daily dose (morphine equivalents), opioid schedule/duration of action, sedative-hypnotic use.
Results: Compared with patients at 1-19 mg/d, risk of opioid overdose death significantly increased at 50-89 mg/d [adjusted hazard ratio (aHR), 2.3; 95% confidence interval (CI), 1.4-4.1], 90-119 mg/d (aHR, 4.0; 95% CI, 2.2-7.3), 120-199 mg/d (aHR, 3.8; 95% CI, 2.1-6.9), and ≥200 mg/d (aHR, 4.9; 95% CI, 2.9-8.1). Patients using long-acting plus short-acting Schedule II opioids had 4.7 times the risk of opioid overdose death than non-Schedule II opioids alone (aHR, 4.7; 95% CI, 3.3-6.9). Sedative-hypnotic use compared with nonuse was associated with 6.4 times the risk of opioid overdose death (aHR, 6.4; 95% CI, 5.0-8.4). Risk was particularly high for opioids combined with benzodiazepines and skeletal muscle relaxants (aHR, 12.6; 95% CI, 8.9-17.9). Even at opioid doses 1-19 mg/d, patients using sedative-hypnotics concurrently had 5.6 times the risk than patients without sedative-hypnotics (aHR, 5.6; 95% CI, 1.6-19.3).
Conclusions: Our findings support Federal guideline-recommended dosing thresholds in opioid prescribing. Concurrent sedative-hypnotic use even at low opioid doses poses substantially greater risk of opioid overdose.