The Workers’ Compensation Research Institute published Impact of Recreational Marijuana Laws on Workers’ Compensation Benefits, a new study that examines how the adoption of state recreational marijuana laws (RMLs) impact workers’ comp claim frequency and outcomes.

The study utilizes data from 31 states from October 2012 to March 2022, analyzing per-claim medical payments, indemnity benefits, temporary disability duration, and prescription drug utilization and costs. The study’s findings can inform policy discussions on topics such as marijuana rescheduling, occupational treatment guidelines, state level regulations, and related issues.

According to WCRI, RMLs led to a gradual increase in workers’ comp claims following RML adoption, averaging a 7.7% increase in claim frequency at 1.7 years of post-RML data. Younger workers saw a larger increase in claim frequency of 9.7%, while workers in safety-sensitive and physically demanding jobs saw 11.7% and 9.9% increases respectively.

RMLs also led to an increase in soft tissue injuries of 8.1%, while the frequency of claims with fractures did not change.

However, while RMLs increased claim counts in adopting states, they did not reverse overall downward trends in claim frequency over the past decade.

Additionally, RMLs reduced medical payments per claim by $207 – or 5.7% - at 12 months of maturity. This was driven in part by changes in prescription utilization and costs among claims with prescriptions.

As a result, RMLs led to a 20% decrease in prescription payments per claim. Furthermore, the number of prescriptions among claims with any prescriptions decreased by 13.9%, including an 11.7% reduction in pain medication prescriptions per claim. The proportion of claims with opioids dropped by 9.7%, while sleep aid prescriptions experienced a minor decrease.