Aims
To examine how the risks of incident opioid use disorder (OUD), nonâfatal and fatal overdose have changed over time among opioidânaive individuals receiving an initial opioid prescription.
Design
Retrospective, longitudinal study using the Massachusetts Chapter 55 data set, which linked multiple administrative data sets to study the opioid epidemic. We identified the cumulative incidence of OUD, nonâfatal and fatal overdose among the opioidânaive initiating opioid treatment in Massachusetts from 2011 to 2014 and estimated rates of these outcomes at 6Â months and at 1, 2, 3 and 4Â years to 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 aged â„ 11 years in 2011â15 who were opioidânaive (no opioid prescriptions or evidence of OUD in the 6 months prior to the index prescription) (n = 2â154â426). 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 nonâfatal overdose were identified from claims in the All Payer Claims Database (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 opioidânaive 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 1âyear OUD rate was 1.18% in 2011, 1.11% in 2012, 1.26% in 2013 and 0.94% in 2014. Longer therapy duration was associated with higher risk of OUD [hazard ratio (HR)Â =Â 2.24, 95% confidence interval (CI)Â =Â 2.19â2.29 for duration of 3 or more months], nonâfatal (HRÂ =Â 1.67, 95% CIÂ =Â 1.53â1.82) and fatal opioid overdose (HRÂ =Â 2.24, 95% CIÂ =Â 1.91â2.61). Concurrent benzodiazepine treatment was also associated with higher risk of OUD (HRÂ =Â 1.14, 95% CI =Â 1.12â1.17), nonâfatal (HRÂ =Â 1.20, 95% CIÂ =Â 1.10â1.30) and fatal overdose (HRÂ =Â 1.86, 95% CI =Â 1.61â2.16).
Conclusions
Among opioidânaive individuals in Massachusetts receiving an initial opioid prescription, the risk of incident opioid use disorder 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 opioid use disorder and opioid overdose.