Changes in Cannabis-Related Health Care Use in Alberta After Cannabis Legalization Between 2018 and 2022: A Population-Based Interrupted Time Series Study

This study investigated the changing pattern of cannabis-related health care use among the general population and subgroups in Alberta, with insights from two significant events: the Cannabis Act amendment (legalization of edibles, extracts, and topicals (EET)) in October 2019 and the COVID-19 pandemic in April 2020. Incidence rates of cannabis-related emergency department or urgent care center (ED/UCC) visits, hospitalizations, cannabinoid hyperemesis syndrome–related ED/UCC visits, Poison and Drug Information Service (PADIS) calls, and Health Link (HL) calls were calculated. Interrupted time-series design was employed to determine level and slope changes in the post-amendment and pandemic periods. Among the general population, the Cannabis Act amendment led to a slope change in cannabis-related PADIS call, but the COVID-19 pandemic led to significant level changes in almost all outcomes. Furthermore, the impact of Cannabis Act amendment and pandemic on cannabis-related health care use varied by age, sex, geography, and socioeconomic status. The increase in cannabis-related health care utilization suggests that further relaxations of the cannabis regulatory framework should carefully consider the short- and long-term impacts on public health and safety.