Incidence of Pediatric Cannabis Exposure Among Children and Teenagers Aged 0 to 19 Years Before and After Medical Marijuana Legalization in Massachusetts.

Importance: Pediatric health care contacts due to cannabis exposure increased in Colorado and Washington State after cannabis (marijuana) policies became more liberal, but evidence from other US states is limited.

Objective: To document the incidence of pediatric cannabis exposure cases reported to the Regional Center for Poison Control and Prevention (RPC) before and after medical marijuana legalization (MML) in Massachusetts.

Design, Setting, And Participants: Cross-sectional comparison of pediatric cannabis exposure cases 4 years before and after MML in Massachusetts.