Trends in Opioid Use Disorder and overdose among opioid-naïve individuals receiving an opioid prescription in Massachusetts from 2011-2014.

AIMS: To examine how the risks of incident opioid use disorder (OUD), nonfatal and fatal overdose have changed over time among opioid-naïve individuals receiving an initial opioid prescription.

DESIGN: Retrospective, longitudinal study using the Massachusetts Chapter 55 dataset which linked multiple administrative datasets to study the opioid epidemic. We identified the cumulative incidence of OUD, nonfatal and fatal overdose among the opioid-naïve initiating opioid treatment in Massachusetts from 2011 to 2014 and estimated rates of these outcomes at 6 months and at 1, 2, 3 and 4 years through 2015. We used Cox regression to examine the association between characteristics of the initial prescription and risk of these outcomes.

SETTING: Massachusetts, USA PARTICIPANTS: Massachusetts residents age ≥11 years in 2011-2015 who were opioid-naïve (no opioid prescriptions or evidence of OUD in the 6 months prior to the index prescription) (n=2,154,426). The mean age was 49.1 years, 55.3% were female and 47.3% had commercial insurance.

MEASUREMENTS: Opioid prescriptions were identified in the Prescription Monitoring Program (PMP) database, as were the characteristics of the initial prescription database. The outcomes of OUD and nonfatal overdose were identified from claims in the APCD and hospital encounters in the Acute Hospital Case Mix Files. Fatal overdoses were identified using Registry of Vital Records and Statistics (RVRS) death certificates and the Office of the Chief Medical Examiner (OCME) circumstances of death and toxicology reports.

FINDINGS: Among opioid-naïve individuals receiving an initial opioid prescription, the risk of incident OUD appears to have declined between 2011 and 2014, while rates of overdose were largely unchanged. For example, the 1-year OUD rate was 1.2% in 2011, 1.1% in 2012, 1.3% in 2013 and 0.9% in 2014. Longer therapy duration was associated with higher risk of OUD (HR 2.24, 95% CI 2.19-2.29 for duration of 3 or more months), nonfatal (HR 1.67, 95% CI 1.53-1.82) and fatal opioid overdose (HR 2.24, 95% CI 1.91-2.6). Concurrent benzodiazepine treatment was also associated with higher risk of OUD (HR 1.14, 95% CI 1.12-1.17), nonfatal (HR 1.20, 95% CI 1.10-1.30) and fatal overdose (HR 1.86, 95% CI 1.61-2.16).

CONCLUSIONS: Among opioid-naïve individuals in Massachusetts receiving an initial opioid prescription, the risk of incident opioid use disorder (OUD) appears to have declined between 2011 and 2014, while rates of overdose were largely unchanged. Longer therapy duration and concurrent benzodiazepines were associated with higher rates of OUD and opioid overdose.