Background and objectives: Canada legalized nonmedical cannabis possession and sale in October 2018. In the United States, state legalization has been tied to an increase in cannabis-related emergency department (ED) visits; however, little research exists on provincial changes in pediatric visits after nationwide legislation. We compared pre- and postlegalization trends in pediatric cannabis-related ED visits and presentation patterns in urban Alberta EDs.

Methods: Retrospective National Ambulatory Care Reporting System data were queried for urban Alberta cannabis-related ED visits among patients aged <18 years from October 1, 2013, to February 29, 2020. Population subgroups included children (aged 0-11 years), younger adolescents (12 to 14 years), and older adolescents (15 to 17 years). We calculated interrupted time series, incident rate ratios (IRRs), and relative risk (RR) ratios to identify trend change. IRRs identified changes against growth-adjusted Alberta population, while RRs measured presentation pattern changes against prelegalization ED visits.

Results: Pediatric visit volume did not change postlegalization when accounting for preexisting volume trends. Unintentional ingestions increased in children (IRR: 1.77, 95% confidence interval [CI]: 1.42 to 2.20 and RR: 1.24, 95% CI: 1.05 to 1.47, respectively) and older adolescents (IRR: 1.36, 95% CI: 1.07 to 1.71 and RR: 1.48, 95% CI: 1.21 to 1.81, respectively). Presentation patterns remained similar, although older adolescent co-ingestant use decreased (RR: 0.77, 95% CI: 0.67 to 0.88), whereas hyperemesis cases increased (RR: 1.64, 95% CI: 1.13 to 2.37).

Conclusions: Cannabis legalization has increased child and older adolescent unintentional cannabis ingestions, increasing child cannabis-related ED visits. Changes highlight need for public health interventions targeting pediatric exposures.

Authors: Matthew E M Yeung, Colin G Weaver, Riley Hartmann, Rebecca Haines-Saah, Eddy Lang