United States healthcare encounters for poisoning involving cannabis relative to other substances

Background: Despite increases in cannabis-related healthcare encounters, research comparing trends in healthcare encounters involving cannabis poisoning with other substances is limited.Objective: To describe healthcare encounters (emergency department [ED] visits and hospitalizations) for poisonings involving cannabis versus other substances (heroin, cocaine, benzodiazepines, alcohol).Methods: We used cross-sectional data from the Nationwide Emergency Department Sample, the National Inpatient Sample (2016–2020), and the National Survey on Drug Use and Health to estimate annual national encounters involving poisoning and utilization-adjusted prevalence per 100,000 individuals reporting past-year use of that substance.Results: From 2016 to 2020, encounters involving cannabis poisoning were lower than heroin and benzodiazepines, and utilization-adjusted prevalence was lower than heroin, cocaine, and benzodiazepines. U.S. cannabis poisoning ED visits (2016: 29,050; 2019: 49,357; 2020: 47,655) and hospitalizations (2016: 12,940; 2019: 18,470; 2020: 13,680) increased between 2016 and 2019, and decreased in 2020, whereas most other substances decreased. Utilization-adjusted prevalence of cannabis poisoning ED visits (2016: 77.3 [95%CI, 70.3–84.3]; 2019: 102.0 [95%CI, 94.7–109.2]; 2020: 98.5 [95%CI, 91.0–106.0]) and hospitalizations (2016: 34.4 [95%CI, 32.6–36.3]; 2019: 38.2 [95%CI, 36.4–39.9]; 2020: 28.3 [95%CI, 26.9–29.7]) followed the same pattern, whereas most other substances declined. In 2020, utilization-adjusted prevalence of transfer/hospital admission was lower for single-substance ED visits involving cannabis poisoning than most other substances. Deaths were higher in single-substance hospitalizations for other substances than cannabis in 2020.Conclusions: Healthcare encounters involving cannabis poisoning increased while remaining lower, and having fewer admissions/deaths, than selected, other substances. These findings can inform healthcare policy and prevention strategies for cannabis-related healthcare encounters.