Trends in Adolescent Cannabis-Related Hospitalizations by State Legalization Laws, 2008-2019.

Purpose: Adolescent cannabis use is associated with adverse health outcomes. The impact of cannabis legalization on adolescent cannabis-related hospitalizations remains unknown. We sought to assess whether state cannabis legalization is associated with adolescent cannabis-related hospitalizations.

Methods: We conducted a retrospective cohort study of adolescent (11-17 years) hospitalizations at children's hospitals between January 1, 2008 and December 31, 2019 using the Inpatient Essentials database. We investigated differences in adolescent cannabis-related diagnosis during a hospitalization by state cannabis legalization status, including states with no legal use to medical cannabis laws (MCLs) and states with MCLs to nonmedical (>21 years old) cannabis laws (NMCLs).

Results: Of 1,898,432 adolescent hospitalizations in 18 states and Washington, DC, there were 37,562 (2%) hospitalizations with a cannabis-related diagnosis, with 8,457 (23%) in states with no legal use, 20,444 (54%) in MCL states, and 8,661 (23%) in NMCL states. There was an increase in adjusted odds of a cannabis-related hospitalization in MCL (odds ratio 1.05, 95% confidence interval 1.04-1.06) and NMCL states (odds ratio 1.03, 95% confidence interval 1.02-1.03) between 2008 and 2019. Characteristics associated with the greatest increase in adjusted odds of a cannabis-related hospitalization postpolicy change included adolescents without an underlying mental health or other substance use disorder in MCL and NMCL states (p < .001) and younger age in NMCL states (13 vs. 16 and 17 years old, p = .02 and p = .02).

Conclusions: Cannabis-related adolescent hospitalizations at children's hospitals are increasing, with a disproportionate increase postlegalization in states with NMCLs. Interventions are warranted to increase cannabis use identification and treatment among at-risk adolescents in the hospital-based setting.