The impact of opioid prescription dose and duration during a workers compensation claim, on post-claim continued opioid use: A retrospective population-based study.

Background: Workers Compensation Board (WCB) recipients are a group commonly prescribed opioids.

Methods: We explored factors influencing post-claim opioid dose and duration by linking data from 22,451 claims with the Manitoba Center for Population Health registry.

Results: On average, the WCB paid for 94.55% of opioids prescribed during a claim. The amount paid for by the WCB varied significantly by total opioids prescribed. The main predictors of high opioid dosage (120 + morphine equivalents (ME)/day) during the first year post-claim (logistic regression), and of longer post-claim opioid usage (survival analysis), included opioid dosage during the final month of the claim both paid for and not paid for by the WCB.

Conclusions: Amongst low dose opioid claims, the WCB covers most opioids prescribed. Higher opioid dose WCB recipients are often prescribed opioids not covered by the WCB. Both opioids paid for and not paid for by the WCB are associated with post-claim opioid use.