Setting the baseline: a description of cannabis poisonings at a Canadian pediatric hospital prior to the legalization of recreational cannabis.

Introduction: This study describes the events and circumstances preceding children aged 16 years or younger being treated for cannabis poisoining in the emergency department (ED) of a Canadian pediatric hospital.

Methods: We extracted cannabis poisoning treated in the ED at British Columbia Children's Hospital (BCCH) between 1 January, 2016 and 31 December, 2018, from the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) database. The poisonings were distinguished by the inadvertent or intentional ingestion of cannabis. We reviewed the hospital's electronic health information system and the patients' health records to obtain additional information on the context, including spatial and temporal characteristics.

Results: Of the 911 poisonings treated at BCCH, 114 were related to intentional cannabis use (12.5%). Fewer than 10 poisonings resulted from inadvertent ingestions by children and the median age for these was 3 years. All inadvertent ingestion occurred at home and involved cannabis belonging to the patient's family. The vast majority of poisonings resulted from the intentional use of cannabis only (28.9%) or cannabis use with other psychoactive substances (co-ingestions; 71.1%). The median patient age was 15 years. Most patients reported consuming cannabis through inhalation with peers. Cannabis and co-ingestion poisonings were more often reported on weekdays than weekends. The consumption of cannabis leading to poisoning more often occurred in private residences. Patients with cannabis poisoning more often sought medical treatment themselves or were helped by their family.

Conclusion: The characteristics of cannabis poisonings among children are described for the three-year period prior to recreational cannabis legalization in Canada in order to set a baseline for future comparisons. Implications for improving injury prevention initiatives and policies are discussed.