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.