Although many states have legalized medical and recreational cannabis, its association with non-fatal opioid poisonings remains unclear. This study examines the association between state cannabis legalization policies and non-fatal opioid poisoning diagnoses among enrollees in employer-sponsored health insurance. The study included 107,480,711 enrollees aged 18–64 with ≥1 year of continuous enrollment (average age 41; 52% females) in the Merative MarketScan Commercial Claims and Encounters Database (2011−2021) in the United States. Utilizing a staggered adoption difference-in-differences regression, this study compared non-fatal opioid poisoning rates in cannabis-legalized and non-legalized states before and after legalization. Four policies were examined: medical cannabis legalization, medical cannabis dispensary opening (MCD), home medical cannabis cultivation, and recreational cannabis legalization (RCL). State MCDs and RCLs were associated with 15.47% (coefficient = −1.73; 95%CI: −2.72, −0.74) and 11.92% (coefficient = −1.33; 95%CI: −2.30, −0.37) reductions in non-fatal opioid poisonings per 100,000 enrollees per quarter, respectively. Reductions associated with MCDs were significant in ages 18–34, males and females, those without prescription opioids or cannabis use disorder diagnoses within the past year, and outpatient service users. State MCDs and RCLs were associated with significant reductions in non-fatal opioid poisonings in the employer-sponsored insured population, particularly among male and younger populations. • Medical cannabis dispensaries were associated with reduced nonfatal opioid poisonings. • Recreational cannabis legalization was associated with reduced nonfatal opioid poisonings. • The reductions were significant among males, females, and adults aged 18–34. • Significant reductions were observed among individuals without past-year opioid prescriptions. • Significant reductions were observed in outpatient services compared to inpatient services.
Hou et al. (Fri,) studied this question.