Geographic clustering of cannabis stores in Canadian cities: A spatial analysis of the legal cannabis market 4 years post-legalisation.

INTRODUCTION: Following the legalisation of non-medical cannabis in 2018, the number of cannabis stores in Canada has rapidly expanded with limited regulation on their geographic placement. This study characterised the clustering of cannabis stores in Canadian cities and evaluated the association of clustering with provincial policy and sociodemographic variables. METHODS: Cross-sectional spatial analysis of cannabis store density in dissemination areas ('neighbourhoods', n = 39,226) in Canadian cities in September 2022. Cannabis store density was defined as the count of stores within 1000 m of a neighbourhood centre. Clusters of high-density cannabis retail were identified using Local Indicators of Spatial Autocorrelation. Associations between provincial policy (privatised vs. public market), sociodemographic variables and cannabis store density were evaluated using multivariable regression. RESULTS: Clusters of high-density cannabis retail were identified in 86% of Canadian cities, and neighbourhoods in clusters had a median of 5 stores within 1000 m. Toronto, Canada's most populous city, had the most extreme clustering where neighbourhoods in clusters had a median of 10 stores (and a maximum of 25 stores) within 1000 m. Neighbourhoods in private versus public retail markets had a significantly higher neighbourhood-level density of cannabis stores (adjusted rate ratio [aRR] 63.37, 95% confidence interval [CI] 25.66-156.33). Lower neighbourhood income quintile was also associated with a higher neighbourhood-level density of cannabis stores (Q5 vs. Q1, aRR 1.28, 95% CI 1.17-1.40). DISCUSSION AND CONCLUSIONS: Since cannabis was legalised, clusters of high-density cannabis retail have emerged in most Canadian cities and were more likely to form lower income neighbourhoods and in private retail markets.

Impact of non-medical cannabis legalization with market restrictions on health service use and incident cases of psychotic disorder in Ontario, Canada.

BACKGROUND: Cannabis is a risk factor in the onset and persistence of psychotic disorders. There is concern that non-medical cannabis legalization in Canada may have population-level impacts on psychotic disorders. We sought to examine changes in health service use and incident cases of psychotic disorder following cannabis legalization, during a period of tight restrictions on retail stores and product types. METHODS: We conducted a cross-sectional interrupted time-series analysis using linked population-based health administrative data from Ontario (Canada) from January 2014 to March 2020. We identified psychosis-related outpatient visits, emergency department visits, hospitalizations, and inpatient length of stay, as well as incident cases of psychotic disorders, among people aged 14 to 60 years. RESULTS: We did not find evidence of increases in health service use or incident cases of psychotic disorders over the short-term (17 month) period following cannabis legalization. However, we found clear increasing trends in health service use and incident cases of substance-induced psychotic disorders over the entire observation window (2014-2020). CONCLUSION: Our findings suggest that the initial period of tight market restriction following legalization of non-medical cannabis was not associated with an increase in health service use or frequency of psychotic disorders. A longer post-legalization observation period, which includes expansion of the commercial cannabis market, is needed to fully understand the population-level impacts of non-medical cannabis legalization; thus, it would be premature to conclude that the legalization of non-medical cannabis did not lead to increases in health service use and incident cases of psychotic disorder.

The effect of non-medical cannabis retailer proximity on use of mental health services for psychotic disorders in Ontario, Canada.

BACKGROUND: Cannabis is associated with the onset and persistence of psychotic disorders. Evidence suggests that accessibility of substances is associated with an increased risk of use-related harms. We sought to examine the effect of residing in proximity to non-medical cannabis retailers on the prevalence of health service use for psychosis. METHODS: We conducted a cross-sectional study using linked health administrative data, and used geospatial analyses to determine whether people in Ontario, Canada (aged 14-60 years) resided within walking (1.6 km) or driving (5.0 km) distance of non-medical cannabis retailers (open as of February-2020). We identified outpatient visits, emergency department (ED) visits, and hospitalizations for psychotic disorders between 01-April-2019 and 17-March-2020. We used zero-inflated Poisson regression models and gamma generalized linear models to estimate the association between cannabis retailer proximity and indicators of health service use. RESULTS: Non-medical cannabis retailers were differentially located in areas with high levels of marginalization and pre-existing health service use for psychosis. People residing within walking or driving distance of a cannabis retailer had a higher rate of psychosis-related outpatient visits, ED visits, and hospitalizations, compared to people living outside these areas. This effect was stronger among those with no prior service use for psychosis. CONCLUSIONS: Proximity to a non-medical cannabis retailer was associated with higher health service use for psychosis, even after adjustment for prior health service use. These findings suggest that opening of non-medical cannabis retailers could worsen the burden of psychosis on mental health services in areas with high-risk populations.

Mortality in adolescents and young adults following a first presentation to the emergency department for alcohol.

BACKGROUND AND METHODS: We conducted a population-based, retrospective cohort study of first-time emergency department (ED) visits in adolescents and young adults (AYA) due to alcohol and compared mortality to AYA with nonalcohol ED visits between 2009 and 2015 using standardized all-cause mortality ratios (age, sex, income, and rurality). We described the cause of death for AYA and examined the association between clinical factors and mortality rates in the alcohol cohort using proportional hazard models. RESULTS: A total of 71,776 AYA had a first-time ED visit due to alcohol (56.1% male, mean age 20.7 years) between 2009 and 2015, representing 3.3% of the 2,166,838 AYA with an ED visit in this time period. At 1 year, there were 2396 deaths, 248 (10.3%) following an ED visit related to alcohol. First-time alcohol ED visits were associated with a threefold higher risk in mortality at 1 year (0.35% vs. 0.10%, adjusted hazard ratio [aHR] 3.07, 95% confidence interval [CI] 2.69-3.51). Mortality was associated with age 25-29 years (aHR 3.88, 95% CI 2.56-5.86), being male (aHR 1.98, 95% CI 1.49-2.62), having a history of mental health or substance use (aHR 3.22, 95% CI 1.64-6.32), cause of visit being withdrawal/dependence (aHR 2.81, 95% CI 1.96-4.02), and having recurrent ED visits (aHR 1.97, 95% CI 1.27-3.05). Trauma (42.7%), followed by poisonings from drugs other than opioids (38.3%), and alcohol (28.6%) were the most common contributing causes of death. CONCLUSION: Incident ED visits due to alcohol in AYA are associated with a high risk of 1-year mortality, especially in young adults, those with concurrent mental health or substance use disorders, and those with a more severe initial presentation. These findings may help inform the need and urgency for follow-up care in this population.

Acute care related to cannabis use during pregnancy after the legalization of nonmedical cannabis in Ontario.

BACKGROUND: Cannabis use during pregnancy is increasing, but the contribution of cannabis legalization to these trends is unclear. We sought to determine whether health service utilization related to cannabis use during pregnancy increased after the legalization of nonmedical cannabis in October 2018 in Ontario, Canada. METHODS: In this population-based, repeated cross-sectional study, we evaluated changes in the number of pregnant people who received acute care (emergency department visit or admission to hospital) between January 2015 and July 2021 among all people eligible for the province's public health coverage. We used segmented regression to compare changes in the quarterly rate of pregnant people with acute care related to cannabis use (primary outcome) with the quarterly rates of acute care for mental health conditions or for noncannabis substance use (control conditions). We identified risk factors associated with acute care for cannabis use and the risk of adverse neonatal outcomes using multivariable logistic regression models. RESULTS: The mean quarterly rate of acute care for cannabis use during pregnancy increased from 11.0 per 100 000 pregnancies before legalization to 20.0 per 100 000 pregnancies after legalization (incidence rate ratio [IRR] 1.82, 95% confidence interval [CI] 1.44-2.31), while acute care for mental health conditions decreased (IRR 0.86, 95% CI 0.78-0.95) and acute care for noncannabis substance use did not change (IRR 1.03, 95% CI 0.91-1.17). Legalization was not associated with an immediate change, but the quarterly change in rates of pregnancies with acute care for cannabis use increased by 1.13 (95% CI 0.46-1.79) per 100 000 pregnancies after legalization. Pregnant people with acute care for cannabis use had greater odds of having received acute care for hyperemesis gravidarum during their pregnancy than those without acute care for cannabis use (30.9% v. 2.5%, adjusted odds ratio [OR] 9.73, 95% CI 8.01-11.82). Pregnancies with acute care for cannabis use had greater odds of newborns being born preterm (16.9% v. 7.2%, adjusted OR 1.93, 95% CI 1.45-2.56) and of requiring care in the neonatal intensive care unit (31.5% v. 13.0%, adjusted OR 1.94 95% CI 1.54-2.44) than those without acute care for cannabis use. INTERPRETATION: The rate of acute care related to cannabis use during pregnancy almost doubled after legalization of nonmedical cannabis, although absolute increases were small. These findings highlight the need to consider interventions to reduce cannabis use during pregnancy in jurisdictions pursuing legalization.

Access to legal cannabis market in Canada over the four years following non-medical cannabis legalisation.

INTRODUCTION: An increasing number of countries are inthe process of legalising non-medical cannabis. We described how the legal market has changed over the first 4 years following legalisation in Canada. METHODS: We collected longitudinal data on operating status and location of all legal cannabis stores in Canada for the first 4 years following legalisation. We examined per capita stores and sales, store closures, and the drive time between stores and each neighbourhood in Canada. We compared measures between public and private retail systems. RESULTS: Four years after legalisation, there were 3305 cannabis stores open in Canada (10.6 stores per 100,000 individuals aged 15+ years). Canadians spent $11.85CAD a month on cannabis per individual aged 15+ years, and 59% of neighbourhoods were within a 5-minute drive of a cannabis store. Over 4 years, per capita stores and per capita sales increased each year by an average of 122.3% and 91.7%, respectively, with larger increases in private versus public systems (4.01 times greater for per capita stores and 2.46 times greater for per capita sales). The annual increase in per capita stores and sales during the first 3 years was 6.0 and 15.5 times greater, respectively, than the increase in the fourth year following legalisation. Over 4 years, 7% of retail store locations permanently closed. DISCUSSION AND CONCLUSION: The legal cannabis market in Canada expanded enormously over the first 4 years following legalisation, with considerable variation in access between jurisdictions. The rapid retail expansion has implications for evaluation of health impacts of non-medical legalisation.

Understanding the association between neighbourhood socioeconomic status and grocery store alcohol sales following market liberalization in Ontario, Canada.

OBJECTIVES: In 2015, Ontario partially deregulated alcohol sales by allowing grocery stores to sell alcohol. The purpose of this study was to evaluate (1) whether neighbourhood-level socioeconomic status (SES) impacted the likelihood that a grocery store began selling alcohol, and (2) whether increases in alcohol retail availability following deregulation differed between neighbourhoods based on SES. METHODS: This was a repeated cross-sectional analysis of 1062 grocery stores in 17,096 neighbourhoods in urban Ontario. The association between neighbourhood-level SES and whether a grocery store began selling alcohol was modeled using mixed effect logistic regression. The annual change in drive-distance from a neighbourhood to the closest off-premise alcohol outlet between 2015 and 2020 was modeled using mixed effect linear regression. An interaction between time and SES was included to evaluate whether this change differed between neighbourhoods based on SES. RESULTS: Grocery stores in neighbourhoods in the lowest SES quintile were 39% less likely to start selling alcohol than grocery stores in neighbourhoods in the highest SES quintile (odds ratio (OR): 0.61, 95% confidence interval (CI): 0.39-0.94). As grocery store sales expanded, the distance to the closest off-premise alcohol outlet decreased by 51.8 m annually (95% CI: 48.8-54.9, p < 0.01). A significant interaction between year and SES was observed whereby this trend was more pronounced in high- versus low-SES neighbourhoods. CONCLUSION: The expansion of grocery store alcohol sales increased alcohol availability, but this increase was proportionately larger in high- versus low-SES neighbourhoods. This reduced historic disparities in alcohol availability between low- and high-SES neighbourhoods.

RéSUMé: OBJECTIFS: En 2015, l'Ontario a partiellement déréglementé les ventes d'alcool en autorisant les épiceries à en vendre. Notre étude visait à évaluer : 1) si le statut socioéconomique (SSE) du quartier avait un effet sur la probabilité qu'une épicerie commence à vendre de l'alcool et 2) si les augmentations de l'accessibilité de l'alcool au détail après la déréglementation différaient d'un quartier à l'autre selon le SSE. MéTHODE: Il s'agissait d'une analyse transversale répétée de 1 062 épiceries dans 17 096 quartiers urbains de l'Ontario. L'association entre le SSE du quartier et le fait qu'une épicerie commence ou non à vendre de l'alcool a été modélisée par régression logistique à effets mixtes. Le changement annuel de la distance de conduite entre un quartier et le point de vente d'alcool hors site le plus proche entre 2015 et 2020 a été modélisé par régression linéaire à effets mixtes. Une interaction entre le temps et le SSE a été incluse pour évaluer si le changement différait d'un quartier à l'autre selon le SSE. RéSULTATS: Les épiceries des quartiers du quintile SSE le plus défavorisé ont été de 39 points de pourcentage moins susceptibles de commencer à vendre de l'alcool que les épiceries des quartiers du quintile SSE le plus favorisé (rapport de cotes [RC] : 0,61, intervalle de confiance de 95 % [(IC] : 0,39-0,94). Avec l'expansion des ventes des épiceries, la distance jusqu'au point de vente d'alcool hors site le plus proche a diminué de 51,8 mètres par année (IC de 95 % : 48,8-54,9, p < 0,01). Une interaction significative entre l'année et le SSE a été observée : cette tendance était plus prononcée dans les quartiers de SSE élevé que dans les quartiers de faible SSE. CONCLUSION: L'expansion des ventes d'alcool des épiceries a fait augmenter l'accessibilité de l'alcool, mais cette augmentation a été proportionnellement plus grande dans les quartiers de SSE élevé que dans les quartiers de faible SSE. Cela a réduit les disparités historiques d'accessibilité de l'alcool entre les quartiers de SSE élevé et de faible SSE.

Associations Between the Physical Availability of Alcohol and Alcohol Use: Regional Variation Across 15 Major Cities in Ontario, Canada.

OBJECTIVE: Rates of alcohol use and alcohol-related harms increase with greater alcohol availability. However, regional differences in sociodemographic characteristics and built environment may affect this association. This study evaluated the association between off-premise alcohol availability and alcohol use in Ontario, Canada, and the degree to which this association varies between cities. METHOD: This was a cross-sectional spatial analysis of urban neighborhoods in Ontario, Canada (n = 11,742). The primary exposure was off-premise alcohol availability, based on the drive time from a neighborhood to the closest off-premise outlets. The primary outcome was the neighborhood-level prevalence of high-volume alcohol use (>2 drinks/day [males], >1 drink/ day [females]) based on survey data from 2000 to 2014. The association between availability and use was assessed using Bayesian hierarchical spatial models to account for spatial autocorrelation. RESULTS: There was an overall positive association between alcohol availability and high-volume alcohol use (male coefficient estimate (ß) = 0.19, 95% credible interval [CI] [0.16, 0.22]; female ß = 0.17, 95% CI [0.13, 0.21]). However, the association was eliminated in models that allowed for this association to vary between cities via an interaction term (male ß = -0.04, 95% CI [-0.26, 0.19]; female ß = -0.04, 95% CI [-0.34, 0.26]). This was explained by variability in the association between cities, where some cities demonstrated a positive association between availability and use and others demonstrated a negative association. CONCLUSIONS: Although there is a province-wide positive association between off-premise alcohol availability and high-volume alcohol use, there is substantial regional variation in this association that may affect the local effectiveness of alcohol regulation policies.

Changes in Emergency Department Visits for Cannabis Hyperemesis Syndrome Following Recreational Cannabis Legalization and Subsequent Commercialization in Ontario, Canada.

Importance: Prior research suggests that the legalization of recreational cannabis is associated with increases in cannabis hyperemesis syndrome (CHS), but it is unclear how cannabis commercialization (ie, greater retail store access as well as increased variety and potency of cannabis products) may be associated with these changes. Objectives: To examine changes in the number and characteristics of CHS emergency department (ED) visits from before to after legalization of cannabis in Ontario, Canada. Design, Setting, and Participants: This repeated cross-sectional study used interrupted time-series analyses to examine immediate and gradual changes in ED visits for CHS in Ontario, Canada, during 3 time periods: prelegalization (January 2014-September 2018), legalization with product and retail store restrictions (October 2018-February 2020), and commercialization with new products and expanded stores, which coincided with the COVID-19 pandemic (March 2020-June 2021). Data were obtained from routinely collected and linked health administrative databases. All individuals aged at least 15 years and who were eligible for Ontario's Universal Health Coverage were included. Data were analyzed between March and July 2022. Main Outcomes and Measures: Monthly counts of ED visits for CHS per capita. Results: There were 12 866 ED visits for CHS from 8140 individuals during the study. Overall, the mean (SD) age was 27.4 (10.5) years, with 2834 individuals (34.8%) aged 19 to 24 years, 4163 (51.5%) females, and 1353 individuals (16.6%) with a mental health ED visit or hospitalization in the 2 years before their first CHS ED visit. Nearly 10% of visits (1135 visits [8.8%]) led to hospital admissions. Monthly rates of CHS ED visits increased 13-fold during the 7.5-year study period, from 0.26 visits per 100 000 population in January 2014 to 3.43 visits per 100 000 population in June 2021. Legalization was not associated with an immediate or gradual change in rates of ED visits for CHS; however, commercialization during the COVID-19 pandemic period was associated with an immediate increase in rates of CHS ED visits (incidence rate ratio [IRR], 1.49; 95% CI, 1.31-1.70). During commercialization, rates of CHS ED visits increased more in women (IRR, 1.49; 95% CI, 1.16-1.92) and individuals older than the legal age of cannabis purchase (eg, age 19-24 years: IRR, 1.60; 95% CI, 1.19-2.16) than men (IRR, 1.08; 95% CI, 0.85-1.37) and individuals younger than the legal age of purchase (IRR, 0.78; 95% CI, 0.42-1.45). Conclusions and Relevance: This cross-sectional study found large increases in CHS ED visits during the period of time when the market commercialized and the COVID-19 pandemic occurred. Greater awareness of CHS symptoms by ED staff in regions where legal commercialized cannabis markets exist is indicated.