Cannabis Legalization and cannabis-Related Hospitalizations in Ontario, Canada

Kim, Chungah; Chum, Antony; Nielsen, Andrew; MacMaster, Frank P.; Rittenbach, Katherine; Allin, Sara; O’Campo, Patricia; Kirst, Maritt; Hamilton, Hayley

doi:10.1177/07067437221114785

Cited by 9 publications

(10 citation statements)

References 3 publications

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“…Although the proportion of consumers who sought help did not increase since legalisation, ER visits increased by approximately 20 percentage points among those who sought help. The self-reported data from the current study are consistent with administrative healthcare data from various regions in Canada, which indicate an increase in ER visits after cannabis legalisation 12–18. Likewise, provincial poison centres in the province of Quebec reported three times the number of calls postlegalisation 37.…”

Section: Discussionsupporting

confidence: 83%

“…Several studies have examined whether more permissive cannabis policies, including the legalisation of non-medical cannabis, are associated with an increase in adverse events from cannabis. Seven studies have examined changes in hospital admissions before and after the federal legalisation of non-medical cannabis in Canada in 2018 12–18. Prior to cannabis legalisation, there was a gradual increase in emergency department visits in Alberta and Ontario, which was accelerated after legalisation 15 16.…”

Section: Introductionmentioning

confidence: 99%

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Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

Marquette,

Iraniparast,

Hammond

2024

BMJ Open

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ObjectivesTo date, there is little evidence on the extent to which cannabis legalisation affects the prevalence of adverse events from cannabis at the population level. The current study examined trends in the prevalence of adverse events among people who consumed cannabis before and after Canada’s legalisation of recreational cannabis.DesignData come from the first four survey waves of the International Cannabis Policy Study, which were conducted online annually immediately prior to non-medical cannabis legalisation in Canada in October 2018, and in the three following years (2019–2021).ParticipantsThe current analysis included 18 285 Canadian respondents aged 16–65 who reported cannabis use in the past 12 months.Outcome measuresPrimary outcomes included types of adverse events experienced from cannabis use, medical help-seeking and the types of products used. Weighted logistic regression models examined differences in help-seeking, emergency room usage and the experience of cannabinoid hyperemesis syndrome across survey years.ResultsApproximately one-third of people who consume cannabis reported experiencing at least one adverse event within the past 12 months, including 5% of consumers who sought medical help for an adverse event, most commonly for panic attacks, feeling faint/dizzy/passing out, heart/blood pressure problems and nausea/vomiting. The prevalence of seeking help and the types of adverse events were similar before (2018) and after legalisation (2019–2021); however, the proportion of consumers seeking help from emergency rooms increased postlegalisation (F=2.77, p=0.041). Adverse events were associated with various product types, with dried flower and oral oils accounting for the largest proportion of events. Help-seeking associated with cannabis edibles significantly decreased after legalisation (p=0.001).ConclusionsSubstantial proportions of people who consume cannabis report adverse events, suggesting widespread difficulty in ‘dosing’. Few changes were observed in the prevalence of adverse events reported by consumers since legalisation; however, the location of medical help-seeking and associated products used have changed postlegalisation.

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Section: Discussionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

Marquette,

Iraniparast,

Hammond

2024

BMJ Open

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“…We summarized findings from five studies of presentations to hospital EDs for cannabis-induced psychosis and mental health presentations, a study of cannabis-positive cases postmortem in Coroner's cases and cannabis-related hospitalizations [13,[39][40][41][42]. Vignault et al [42] assessed the short-term impact of the legalization on cannabis use, cannabis use disorder and psychotic disorders among patients in one Quebec hospital before and 5 months after cannabis use was legalized.…”

Section: Health Service Presentationsmentioning

confidence: 99%

“…We summarized findings from five studies of presentations to hospital EDs for cannabis‐induced psychosis and mental health presentations, a study of cannabis‐positive cases postmortem in Coroner's cases and cannabis‐related hospitalizations [ 13 , 39 , 40 , 41 , 42 ]. Vignault et al .…”

Section: Public Health and Safety After Legalizationmentioning

confidence: 99%

The implementation and public health impacts of cannabis legalization in Canada: a systematic review

et al. 2023

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AimsWe provide a narrative summary of research on changes in cannabis arrests, cannabis products and prices, cannabis use and cannabis‐related harm since legalization.MethodsWe systematically searched for research on the impacts of cannabis legalization in Canada in PubMed, Embase, Statistics Canada and government websites and Google Scholar, published between 2006 and 2021.ResultsCannabis legalization in Canada has been followed by substantial reductions in cannabis‐related arrests and cannabis prices. It has also increased adults’ access to a diverse range of cannabis products, including edibles and extracts. The prevalence of cannabis use among young adults has increased, but there have been no marked increases or decreases in use among high school students or changes in the prevalence of daily or near‐daily use. Legalization has been associated with increased adult hospital attendances for psychiatric distress and vomiting, unintentional ingestion of edible cannabis products by children and hospitalizations for cannabis use disorders in adults. There is conflicting evidence on whether cannabis‐impaired driving has increased since legalization. There is suggestive evidence that presentations to emergency departments with psychoses and cannabis use disorders may have increased since legalization.ConclusionsLegalization of cannabis in Canada appears to have reduced cannabis arrests and increased access to a variety of more potent cannabis products at lower prices. Since 2019, recent cannabis use in Canada has modestly increased among adults but not among adolescents. There is evidence of increased acute adverse effects of cannabis among adults and children.

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“…Several studies have investigated changes over time in ED visits due to cannabis in two provinces (Alberta or Ontario) in Canada following legalization . Two brief reports have also examined changes in hospitalizations due to cannabis—a potentially more severe and specific indicator of cannabis-related health harms—in Ontario and Quebec . Studies to date have used differing lengths of follow-up and not compared changes following legalization in health service use due to cannabis between provinces or at the national level.…”

Section: Introductionmentioning

confidence: 99%

Changes in Cannabis-Attributable Hospitalizations Following Nonmedical Cannabis Legalization in Canada

Myran,

Gaudreault,

Konikoff

et al. 2023

JAMA Netw Open

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ImportanceThe impact of adult-use cannabis legalization and subsequent commercialization (ie, increasing store and product access) on hospitalizations in Canada is unclear.ObjectivesTo examine changes in overall and subtypes of hospitalizations due to cannabis and associated factors following legalization in Canada and to compare changes between provinces.Design, Setting, and ParticipantsThis repeated cross-sectional analysis included all acute hospitalizations for individuals aged 15 to 105 years in Canada’s 4 most populous provinces (Ontario, Quebec, Alberta and British Columbia, population 26.9 million individuals in 2018). Data were obtained from routinely collected health administrative databases. Immediate and gradual changes in the age- and sex-standardized rates of hospitalizations due to cannabis were compared using an interrupted time series design over 3 time periods: prelegalization (January 2015 to September 2018), legalization with product and store restrictions (October 2018 to February 2020), and commercialization, which overlapped with the COVID-19 pandemic (March 2020 to March 2021).Main Outcomes and MeasuresRates of hospitalizations due to cannabis per 100 000 individuals and per 1000 all-cause hospital admissions.ResultsThere were 105 203 hospitalizations due to cannabis over the 7-year study period, 69 192 of which (65.8%) were among male individuals, and 34 678 (33%) of which were among individuals aged 15 to 24 years. Overall, the age- and sex-standardized rate of hospitalizations increased 1.62 times between January 2015 (3.99 per 100 000 individuals) and March 2021 (6.46 per 100 000 individuals). The largest relative increase in hospitalizations was for cannabis-induced psychosis (rate ratio, 1.40; 95% CI, 1.34 to 1.47 during the commercialization period relative to the prelegalization period). Nationally, legalization with restrictions was associated with a gradual monthly decrease of −0.06 (95% CI −0.08 to −0.03) in hospitalizations due to cannabis per 100 000 individuals. Commercialization and the COVID-19 pandemic were associated with an immediate increase of 0.83 (95% CI, 0.30 to 1.30) hospitalizations due to cannabis per 100 000 individuals. There was provincial variation in changes, with provinces with less mature legal markets experiencing the greatest declines immediately following legalization.Conclusions and RelevanceThis cross-sectional study found that legalization with restrictions was not associated with an increase in hospitalizations due to cannabis but commercialization was. The findings suggest that commercialization of cannabis may be associated with increases in cannabis-related health harms, including cannabis-induced psychosis.

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Cannabis Legalization and cannabis-Related Hospitalizations in Ontario, Canada

Cited by 9 publications

References 3 publications

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

Adverse outcomes of cannabis use in Canada, before and after legalisation of non-medical cannabis: cross-sectional analysis of the International Cannabis Policy Study

The implementation and public health impacts of cannabis legalization in Canada: a systematic review

Changes in Cannabis-Attributable Hospitalizations Following Nonmedical Cannabis Legalization in Canada

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