Association between non-medical cannabis legalization and emergency department visits for cannabis-induced psychosis.

A major public health concern of cannabis legalization is that it may result in an increase in psychotic disorders. We examined changes in emergency department (ED) visits for cannabis-induced psychosis following the legalization and subsequent commercialization (removal of restrictions on retail stores and product types) of non-medical cannabis in Ontario, Canada (population of 14.3 million). We used health administrative data containing the cause of all ED visits to examine changes over three periods; 1) pre-legalization (January 2014-September 2018); 2) legalization with restrictions (October 2018 - February 2020); and 3) commercialization (March 2020 - September 2021). We considered subgroups stratified by age and sex and examined cocaine- and methamphetamine-induced psychosis ED visits as controls. During our study, there were 6300 ED visits for cannabis-induced psychosis. The restricted legalization period was not associated with changes in rates of ED visits for cannabis-induced psychosis relative to pre-legalization. The commercialization period was associated with an immediate increase in rates of ED visits for cannabis-induced psychosis (IRR 1.30, 95% CI 1.02-1.66) and no gradual monthly change; immediate increases were seen only for youth above (IRR 1.63, 1.27-2.08, ages 19-24) but not below (IRR 0.73 95%CI 0.42-1.28 ages, 15-18) the legal age of purchase, and similar for men and women. Commercialization was not associated with changes in rates of ED visits for cocaine- or methamphetamine-induced psychosis. This suggests that legalization with store and product restrictions does not increase ED visits for cannabis-induced psychosis. In contrast, cannabis commercialization may increase cannabis-induced psychosis presentations highlighting the importance of preventive measures in regions considering legalization.

Unintentional pediatric poisonings before and during the COVID-19 pandemic: A population-based study.

OBJECTIVES: The impact of coronavirus disease 2019 (COVID-19) on unintentional pediatric poisonings is unclear. We examined changes in emergency department (ED) visits and hospitalizations for poisonings before and during the COVID-19 pandemic. We compared changes in cannabis vs non-cannabis poisoning events given the recent legalization of cannabis in October 2018 and cannabis edibles in January 2020. STUDY DESIGN: Interrupted time-series (ITS) analyses of changes in population-level ED visits and hospitalizations for poisonings in children aged 0-9 years in Ontario, Canada (annual population of 1.4 million children), over two time periods: pre-pandemic (January 2010-March 2020) and pandemic (April 2020-December 2021). RESULTS: Overall, there were 28,292 ED visits and 2641 hospitalizations for unintentional poisonings. During the pandemic, poisonings per 100,000 person-years decreased by 14.6% for ED visits (40.15 pre- vs. 34.29 during) and increased by 35.9% for hospitalizations (3.48 pre- vs. 4.73 during). ED visits dropped immediately (Incidence Rate Ratio [IRR], 0.76; 95% CI, 0.70-0.82) at the onset of the pandemic, followed by a gradual return to baseline (quarterly change, IRR 1.04, 95%CI 1.03-1.06), while hospitalizations had an immediate increase (IRR 1.34; 95% CI, 1.08-1.66) and no gradual change. The only increase in poisonings was for cannabis which had a 10.7-fold for ED visits (0.45 to 4.83 per 100,000 person-years) and a 12.1-fold increase for hospitalizations (0.16 to 1.91 per 100,000 person-years). Excluding cannabis, there was no overall increase in poisoning hospitalizations. CONCLUSIONS: The COVID-19 pandemic was not associated with increases in any type of unintentional pediatric poisonings, with the exception of cannabis poisonings. Increased cannabis poisonings may be explained by the legalization of non-medical cannabis edibles in Canada in January 2020.

Mental health and addiction health service use by physicians compared to non-physicians before and during the COVID-19 pandemic: A population-based cohort study in Ontario, Canada.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic has exacerbated mental health challenges among physicians and non-physicians. However, it is unclear if the worsening mental health among physicians is due to specific occupational stressors, reflective of general societal stressors during the pandemic, or a combination. We evaluated the difference in mental health and addictions health service use between physicians and non-physicians, before and during the COVID-19 pandemic. METHODS AND FINDINGS: We conducted a population-based cohort study in Ontario, Canada between March 11, 2017 and August 11, 2021 using data collected from Ontario's universal health system. Physicians were identified using registrations with the College of Physicians and Surgeons of Ontario between 1990 and 2020. Participants included 41,814 physicians and 12,054,070 non-physicians. We compared the first 18 months of the COVID-19 pandemic (March 11, 2020 to August 11, 2021) to the period before COVID-19 pandemic (March 11, 2017 to February 11, 2020). The primary outcome was mental health and addiction outpatient visits overall and subdivided into virtual versus in-person, psychiatrists versus family medicine and general practice clinicians. We used generalized estimating equations for the analyses. Pre-pandemic, after adjustment for age and sex, physicians had higher rates of psychiatry visits (aIRR 3.91 95% CI 3.55 to 4.30) and lower rates of family medicine visits (aIRR 0.62 95% CI 0.58 to 0.66) compared to non-physicians. During the first 18 months of the COVID-19 pandemic, the rate of outpatient mental health and addiction (MHA) visits increased by 23.2% in physicians (888.4 pre versus 1,094.7 during per 1,000 person-years, aIRR 1.39 95% CI 1.28 to 1.51) and 9.8% in non-physicians (615.5 pre versus 675.9 during per 1,000 person-years, aIRR 1.12 95% CI 1.09 to 1.14). Outpatient MHA and virtual care visits increased more among physicians than non-physicians during the first 18 months of the pandemic. Limitations include residual confounding between physician and non-physicians and challenges differentiating whether observed increases in MHA visits during the pandemic are due to stressors or changes in health care access. CONCLUSIONS: The first 18 months of the COVID-19 pandemic was associated with a larger increase in outpatient MHA visits in physicians than non-physicians. These findings suggest physicians may have had larger negative mental health during COVID-19 than the general population and highlight the need for increased access to mental health services and system level changes to promote physician wellness.

Association of Extracorporeal Membrane Oxygenation With New Mental Health Diagnoses in Adult Survivors of Critical Illness.

Importance: Extracorporeal membrane oxygenation (ECMO) is used as temporary cardiorespiratory support in critically ill patients, but little is known regarding long-term psychiatric sequelae among survivors after ECMO. Objective: To investigate the association between ECMO survivorship and postdischarge mental health diagnoses among adult survivors of critical illness. Design, Setting, and Participants: Population-based retrospective cohort study in Ontario, Canada, from April 1, 2010, through March 31, 2020. Adult patients (N=4462; age ≥18 years) admitted to the intensive care unit (ICU), and surviving to hospital discharge were included. Exposures: Receipt of ECMO. Main Outcomes and Measures: The primary outcome was a new mental health diagnosis (a composite of mood disorders, anxiety disorders, posttraumatic stress disorder; schizophrenia, other psychotic disorders; other mental health disorders; and social problems) following discharge. There were 8 secondary outcomes including incidence of substance misuse, deliberate self-harm, death by suicide, and individual components of the composite primary outcome. Patients were compared with ICU survivors not receiving ECMO using overlap propensity score-weighted cause-specific proportional hazard models. Results: Among 642 survivors who received ECMO (mean age, 50.7 years; 40.7% female), median length of follow-up was 730 days; among 3820 matched ICU survivors who did not receive ECMO (mean age, 51.0 years; 40.0% female), median length of follow-up was 1390 days. Incidence of new mental health conditions among survivors who received ECMO was 22.1 per 100-person years (95% confidence interval [CI] 19.5-25.1), and 14.5 per 100-person years (95% CI, 13.8-15.2) among non-ECMO ICU survivors (absolute rate difference of 7.6 per 100-person years [95% CI, 4.7-10.5]). Following propensity weighting, ECMO survivorship was significantly associated with an increased risk of new mental health diagnosis (hazard ratio [HR] 1.24 [95% CI, 1.01-1.52]). There were no significant differences between survivors who received ECMO vs ICU survivors who did not receive ECMO in substance misuse (1.6 [95% CI, 1.1 to 2.4] per 100 person-years vs 1.4 [95% CI, 1.2 to 1.6] per 100 person-years; absolute rate difference, 0.2 per 100 person-years [95% CI, -0.4 to 0.8]; HR, 0.86 [95% CI, 0.48 to 1.53]) or deliberate self-harm (0.4 [95% CI, 0.2 to 0.9] per 100 person-years vs 0.3 [95% CI, 0.2 to 0.3] per 100 person-years; absolute rate difference, 0.1 per 100 person-years [95% CI, -0.2 to 0.4]; HR, 0.68 [95% CI, 0.21 to 2.23]). There were fewer than 5 total cases of death by suicide in the entire cohort. Conclusions and Relevance: Among adult survivors of critical illness, receipt of ECMO, compared with ICU hospitalization without ECMO, was significantly associated with a modestly increased risk of new mental health diagnosis or social problem diagnosis after discharge. Further research is necessary to elucidate the potential mechanisms underlying this relationship.

Changes in the dollar value of per capita alcohol, essential, and non-essential retail sales in Canada during COVID-19.

BACKGROUND: Multiple survey reports suggest that alcohol use has increased in Canada during the COVID-19 pandemic. However, less is known about how per capita alcohol sales, which predict population-level alcohol use, have changed and whether changes in alcohol sales differ from changes in sales of other products due to pandemic factors. METHODS: We obtained monthly retail sales data by industry from Statistics Canada, for the six largest provinces in Canada (containing 93% of the national population), between January 2010 and November 2020, representing time before and 9 months after the start of the pandemic in Canada. We used an interrupted time series analysis to estimate pandemic impacts on the dollar value of monthly per capita (per individuals 15+ years) alcohol, essential and non-essential retail sales. We adjusted our analyses for pre-pandemic sales trends, inflation, seasonality and changing population demographics over time. RESULTS: During the first 9 months of the pandemic, the values of per capita alcohol, essential and non-essential sales were, respectively, 13.2% higher, 3.6% higher and 13.1% lower than the average values during the same period in the prior 3 years. Interrupted time series models showed significant level change for the value of monthly per capita alcohol sales (+$4.86, 95% CIs: 2.88, 6.83), essential sales (-$59.80, 95% CIs: - 78.47, - 41.03) and non-essential sales (-$308.70, 95% CIs: - $326.60, - 290.79) during the pandemic. Alcohol sales were consistently elevated during the pandemic, and the pre- and post-pandemic slopes were comparable. In contrast, essential and non-essential retail sales declined in the early months of the pandemic before returning to regular spending levels. CONCLUSION: During the first 9 months of the pandemic, per capita alcohol sales were moderately elevated in Canada. In contrast, non-essential sales were lower than prior years, driven by large decreases during the initial months of the pandemic. These findings suggest that the pandemic was associated with increased population-level alcohol consumption, which may lead to increased alcohol-related harms. Ongoing research is needed to examine how factors, including pandemic-related stressors and specific alcohol sales-related policies, may have influenced changes in alcohol use and harms.

Alcohol Availability Across Neighborhoods in Ontario Following Alcohol Sales Deregulation, 2013-2017.

Objectives. To examine the association between neighborhood socioeconomic status (SES) and alcohol availability before and after deregulation in 2015 of the alcohol market in Ontario, Canada. Methods. We quantified alcohol access by number of alcohol outlets and hours of retail for all 19 964 neighborhoods in Ontario. We used mixed effects regression models to examine the associations between alcohol access and a validated SES index between 2013 and 2017. Results. Following deregulation, the number of alcohol outlets in Ontario increased by 15.0%. Low neighborhood SES was positively associated with increased alcohol access: lower-SES neighborhoods had more alcohol outlets within 1000 meters and were closer to the nearest alcohol outlets. Outlets located in low-SES neighborhoods kept longer hours of operation. Conclusions. We observed a substantial increase in alcohol access in Ontario following deregulation. Access to alcohol was greatest in low-SES neighborhoods and may contribute to established inequities in alcohol harms. Public Health Implications. Placing limits on number of alcohol outlets and the hours of operation in low-SES neighborhoods offers an opportunity to reduce alcohol-related health inequities.

Rates of emergency department visits attributable to alcohol use in Ontario from 2003 to 2016: a retrospective population-level study.

BACKGROUND: Alcohol use causes a large burden on the health of Canadians, and alcohol-related harms appear to be increasing in many high-income countries. We sought to analyze changes in emergency department visits attributable to alcohol use, by sex, age and neighbourhood income over time. METHODS: All individuals aged 10 to 105 years living in Ontario, Canada, between 2003 and 2016 were included in this study. The primary outcome was age-standardized rates of emergency department visits attributable to alcohol use, defined using diagnostic codes from the Canadian Institute for Health Information Health Indicator "hospitalizations entirely caused by alcohol." We compared rates of these visits using a retrospective population-level design. RESULTS: Among 15 121 639 individuals, there were 765 346 emergency department visits attributable to alcohol use over the study period. Between 2003 and 2016, the age-standardized rates of these visits increased more in women (86.5%) than in men (53.2%), and the increase in rates of emergency department visits attributable to alcohol use was 4.4 times greater than the increases in the rates of overall emergency department visits. Individuals aged 25-29 years experienced the largest change in the rate of emergency department visits attributable to alcohol use (175%). We found evidence of age-cohort effects, whereby the rate of emergency department visits attributable to alcohol use at age 19 years increased on average by 4.07% (95% confidence interval [CI] 3.71%-4.44%) per year for each cohort born between 1986 and 1999. Individuals in the lowest neighbourhood income quintile had 2.37 (95% CI 2.27-2.49) times the rate of emergency department visits attributable to alcohol use than those in the highest income quintile. This disparity increased slightly over the study period. INTERPRETATION: Although men and lower-income individuals have the highest burden of emergency department visits attributable to alcohol use, the largest increases in visits have been in women and younger adults. Further research should focus on potential causes of these trends to provide guidance on how to reduce alcohol-related harms.

Abortion education in Canadian family medicine residency programs.

BACKGROUND: Abortion has been decriminalized in Canada since 1988 and is considered an essential medical service. There is concern that decreasing numbers of abortion providers may impair access to abortion. This study examined the quantity of exposure and education that Canadian family medicine residents receive on abortion during training and their preparation to provide abortions. In addition, the study assessed residents' attitudes, intention and expressed competency to provide abortion in future practice and the association between medical training and changes in these factors. METHODS: The authors developed a 21-item survey in consultation with experts in medical education. The survey was distributed online in 2016. A total of 1517 family medicine residents in their first, second and third year of training attending 8 English language schools across Canada were invited to participate. Associations between attitudes, education, exposure and intention were assessed using relative risks based on bivariate analysis of self-reported measures and odds ratios from ordered logistic regression. RESULTS: The response rate was 28.7% (436/1517). The majority of residents, 79%, reported never observing or assisting with an abortion during training. Similarly, 80% of residents reported receiving less than 1 hour of formal education on abortion. Residents strongly supported receiving abortion education. Self reported exposure to a single abortion during training was associated with an increase in residents' intention (RR = 1.95, 95% CI 1.54-2.47) and self-rated competency to provide a medical abortion (RR = 2.16, 95% CI 1.60-2.93). Twenty five percent of residents were unaware of ethical and legal requirements towards abortion provision and referral. CONCLUSIONS: Canadian family medicine residents receive little education or exposure to abortion during training most do not feel competent to provide abortion services. Residents expressed strong support for receiving abortion training. The Canadian College of Family Physicians curriculum does not currently include abortion as a training objective. The authors argue there is a need for family medicine training programs to increase education and exposure to abortion during residency, while respecting residents' rights to opt out of such training. Failure to do so may impair future access to abortion provision.

Cognitive Decline in Long-term Care Residents Before and During the COVID-19 Pandemic in Ontario, Canada.

This study examines the incidence of cognitive decline among long-term care residents in Ontario before and during the COVID-19 pandemic.

Medical students' intentions to seek abortion training and to provide abortion services in future practice.

OBJECTIVES: Lack of providers is a barrier to accessing abortion in Canada. The factors influencing the number of abortion providers are poorly understood. In this study, we assessed the attitudes and intentions of medical students towards abortion training and provision to gain insight into the future supply of abortion providers. METHODS: We surveyed first, second, and third year medical students at an Ontario university to determine their intentions to train in and provide abortion services during different stages of training and in future practice. We assessed students' attitudes and intentions towards training in and providing abortions, their perceptions of social support, their perceived ability to receive training in and to provide abortion services, and their attitudes towards the legality of abortion. RESULTS: Surveys were completed by 337 of 508 potential respondents (66.7%). The responses indicated that the students in the survey held relatively positive attitudes towards the legality and availability of abortion in Canada. Respondents had significantly more positive attitudes towards first trimester medical abortions (and a greater intention to provide them) than towards second trimester surgical abortions. Thirty-five percent of students planned to enter a specialty in which they could perform abortions, but fewer than 30% of these students planned to provide any type of abortion. Intentions to provide abortions were correlated with positive attitudes toward abortion in general and greater perceived social support for abortion provision. CONCLUSION: A small proportion of students sampled intended both to enter a specialty in which abortion would be within the scope of practice and to provide abortion services. Lack of perceived social support for providing abortions and the perceived inability to obtain abortion training or to logistically provide abortions were identified as two potentially modifiable barriers to abortion provision. We propose increasing education on abortion provision and creating policies to promote medical abortion as a method of improving access to abortion across Canada.

Objectifs : Au Canada, l'accès à des services d'avortement est entravé par le manque de fournisseurs de soins étant en mesure d'offrir de tels services. Les facteurs qui influencent le nombre de fournisseurs de services d'avortement sont mal compris. Dans le cadre de cette étude, nous avons évalué les attitudes et les intentions des étudiants de médecine en ce qui concerne la formation en matière d'avortement et l'offre de tels services dans le cadre de leur future pratique, et ce, pour en connaître davantage au sujet de nos futurs effectifs dans ce domaine. Méthodes : Nous avons sondé les étudiants de médecine de première, de deuxième et de troisième année d'une université ontarienne, à différents stades de leur formation (et en leur demandant de remplir un questionnaire traitant de la future pratique qu'ils envisageaient), en vue de déterminer leurs intentions en ce qui concerne l'obtention d'une formation en matière d'avortement et l'offre de services d'avortement. Nous avons évalué les attitudes et les intentions de ces étudiants en ce qui concerne l'obtention d'une formation en matière d'avortement et l'offre de services d'avortement, leurs perceptions en ce qui a trait au soutien social, leur capacité subjective de recevoir une formation en matière d'avortement et d'offrir des services d'avortement, et leurs attitudes envers la légalité de l'avortement. Résultats : Trois cent trente-sept des 508 répondants potentiels (66,7 %) ont répondu aux questionnaires. Les réponses indiquent que les répondants adoptaient des attitudes relativement positives envers la légalité et la disponibilité de l'avortement au Canada. Les répondants adoptaient des attitudes considérablement plus positives envers les avortements médicaux au premier trimestre (et un plus grand nombre d'entre eux avaient l'intention d'offrir de tels services) qu'envers les avortements chirurgicaux menés au deuxième trimestre. Trente-cinq pour cent des étudiants avaient l'intention de choisir une spécialité dans le cadre de laquelle latenue d'avortements serait possible; toutefois, moins de 30 % de ces étudiants avaient l'intention d'offrir quelque type de services d'avortement que ce soit. Les intentions d'offrir des services d'avortement étaient en corrélation avec les attitudes positives envers l'avortement en général et avec la perception d'un soutien social accru envers l'offre de services d'avortement. Conclusion : Une faible proportion de l'échantillon d'étudiants analysé avait l'intention de choisir une spécialité dont le champ d'activité englobe la tenue d'avortements et d'offrir des services d'avortement. L'absence subjective de soutien social envers l'offre de services d'avortement et l'incapacité subjective d'obtenir une formation en matière d'avortement ou d'offrir des services d'avortement au plan logistique ont été identifiés comme étant deux obstacles potentiellement modifiables pour ce qui est de l'offre de services d'avortement. Pour assurer l'amélioration de l'accès à l'avortement d'un bout à l'autre du Canada, nous proposons l'augmentation des efforts d'éducation au sujet de l'offre de services d'avortement et la création de politiques visant la promotion de l'avortement médical.

Cannabis-involvement in emergency department visits for self-harm following medical and non-medical cannabis legalization.

AIMS: Cannabis use may increase the risk of self-harm, but whether legalization of cannabis is associated with changes in self-harm is unknown. We examined changes in cannabis-involvement in emergency department (ED) visits for self-harm after the liberalization of medical and legalization of non-medical cannabis in Canada. METHODS: This repeated cross-sectional study used health administrative data to identify all ED visits for self-harm in individuals aged ten and older between January 2010 and December 2021. We identified self-harm ED visits with a co-diagnosis of cannabis (main exposure) or alcohol (control condition) and examined changes in rates of visits over four distinct policy periods (pre-legalization, medical liberalization, non-medical legalization with restrictions, and non-medical commercialization/COVID-19) using Poisson models. RESULTS: The study included 158,912 individuals with one or more self-harm ED visits, of which 7810 (4.9 %) individuals had a co-diagnosis of cannabis use and 24,761 (15.6 %) had a co-diagnosis of alcohol use. Between 2010 and 2021, the annual rate of ED visits for self-harm injuries involving cannabis per 100,000 individuals increased by 90.1 % (3.6 in 2010 to 6.9 in 2021 per 100,000 individuals), while the annual rate of self-harm injuries involving alcohol decreased by 17.3 % (168.1 in 2010 to 153.1 in 2021 per 100,000 individuals). The entire increase in visits relative to pre-legalization occurred after medical liberalization (seasonally adjusted Risk Ratio [asRR] 1.71 95 % CI 1.09-1.15) with no further increases during the legalization with restrictions (asRR 1.77 95%CI 1.62-1.93) or commercialization/COVID-19 periods (asRR 1.63 95%CI 1.50-176). CONCLUSIONS: Cannabis-involvement in self-harm ED visits almost doubled over 12 years and may have accelerated after medical cannabis liberalization. While the results cannot determine whether cannabis is increasingly causing self-harm ED visits or whether cannabis is increasingly being used by individuals at high risk of self-harm, greater detection for cannabis use in this population and intervention may be indicated.

Changes in cannabis involvement in emergency department visits for anxiety disorders after cannabis legalization: a repeated cross-sectional study.

Background: An increasing number of countries have or are considering legalizing cannabis. One concern is that legalization of cannabis will result in increased cannabis use and in turn a higher prevalence of anxiety disorders. We examined changes in emergency department (ED) visits for anxiety disorders with cannabis involvement in Ontario, over a period that involved medical and non-medical cannabis legalization. Methods: This repeated cross-sectional population-based study identified all ED visits for anxiety disorders from residents of Ontario, Canada aged 10-105 between 2008 and 2022 (n = 15.7 million individuals). We used interrupted time series analyses to examine immediate and gradual changes in cannabis-involvement and alcohol-involvement (control condition) over four policy periods: medical cannabis legalization (January 2008-November 2015), expanded medical access (December 2015-September 2018), non-medical cannabis legalization with restrictions (October 2018-February 2020), and commercialization which overlapped with the COVID-19 pandemic (March 2020-December 2022). Poisson models were used to generate incidence rate ratios with 95% confidence intervals. Findings: Over the 14-year study, there were 438,700 individuals with one or more ED visits for anxiety disorders of which 3880 (0.89%) individuals had cannabis involvement and 6329 (1.45%) individuals had alcohol involvement. During the commercialization/COVID-19 period monthly rates of anxiety disorders with cannabis-involvement were 156% higher (0.11 vs 0.29 per 100,000 individuals) relative to the pre-legalization period, compared to a 27% increase for alcohol-involvement (0.27 vs 0.35 per 1100,000 individuals). Rates of anxiety ED visits with cannabis involvement per 100,000 individuals increased gradually over the study period with no immediate or gradual changes after expanded medical access, legalization with restrictions or commercialization/COVID-19. However, during the commercialization/COVID-19 period there were large declines in total anxiety disorder ED visits and anxiety disorder ED visits with alcohol-involvement. Consequently, during this period there was an immediate 31.4% relative increase in the proportion of anxiety visits with cannabis-involvement (incidence rate ratio [IRR], 1.31; 95% CI 1.05-1.65). Interpretation: We found large relative increases in anxiety disorder ED visits with cannabis involvement over a 14-year period involving medical and non-medical cannabis legalization. These findings may reflect increasing anxiety disorder problems from cannabis use, increasing self-medication of anxiety disorders with cannabis use, or both. The proportion of anxiety ED visits with cannabis involvement increased during the final period of the study but could have been the results of the market commercialization, COVID-19 or both and ongoing monitoring is indicated. Funding: Canadian Institutes of Health Research (grant #452360).

Development of an anxiety disorder following an emergency department visit due to cannabis use: a population-based cohort study.

Background: There is ongoing uncertainty about whether cannabis use increases the risk of developing an anxiety disorder. In this study we estimated the risk of having an incident healthcare visit for an anxiety disorder following an emergency department (ED) visit for cannabis use and explored factors associated with increased risk. Methods: We used health administrative data to perform a population-based cohort study of all individuals aged 10-105 years with no previous healthcare visits for anxiety disorders in Ontario, Canada, between January 2008 and March 2019. We compared the risk of having an incident healthcare visit for an anxiety disorder in the ED or hospital (primary analysis) or additionally in an outpatient setting (secondary analysis) for individuals with an incident ED visit for cannabis to members of the general population using cumulative incidence functions and cause-specific hazard models adjusted for relevant confounders. Findings: Our study included 12,099,144 individuals aged 10-105 without prior care for an anxiety disorder in the ED or hospital, of which 34,822 (0.29%) had an incident ED visit due to cannabis. Within 3-years of an incident ED visit due to cannabis, 12.3% (n = 4294) of individuals had an incident ED visit or hospitalization for an anxiety disorder-a 3.7-fold (adjusted Hazard Ratio [aHR] 3.69 95% CI 3.57-3.82) increased risk relative to the general population (1.2%). In secondary analysis, further excluding individuals with prior outpatient care for anxiety disorders, 23.6% of individuals with an ED visit due to cannabis had an incident outpatient visit, ED visit, or hospitalization for an anxiety disorder within 3-years compared to 5.6% of individuals in the general population (aHR 3.88 95% CI 3.77-2.99). The risk of having an incident healthcare visit for an anxiety disorder was higher in individuals with ED visits for cannabis use compared to the general population across all age and sex strata. However, younger males with ED visits for cannabis use (aHR 5.67 95% CI 5.19-6.21) had a greater risk relative to the general population than younger women with cannabis use (aHR 3.22 95% CI 2.95-3.52). Interpretation: ED visits for cannabis use were associated with an increased risk of having an incident healthcare visit for an anxiety disorder, particularly in young males. These findings have important clinical and policy implications given the increasing use of cannabis over time and trend towards legalization of cannabis. Funding: Canadian Institutes for Health Research.

COVID-19 vaccine uptake among Ontario physicians: a descriptive population-based retrospective cohort study.

OBJECTIVES: To determine COVID-19 vaccine uptake among physicians in Ontario, Canada from 14 December 2020 to 13 February 2022. DESIGN: Population-based retrospective cohort study. SETTING: All registered physicians in Ontario, Canada using data from linked provincial administrative healthcare databases. PARTICIPANTS: 41 267 physicians (including postgraduate trainees) who were Ontario residents and registered with the College of Physicians and Surgeons of Ontario were included. Physicians who were out of province, had not accessed Ontario Health Insurance Plan-insured services for their own care for ≥5 years and those with missing identifiers were excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were the proportions of physicians who were recorded to have received at least one, at least two and three doses of a Health Canada-approved COVID-19 vaccine by study end date. Secondary outcomes were how uptake varied by physician characteristics (including age, sex, specialty and residential location) and time elapsed between doses. RESULTS: Of 41 267 physicians, (56% male, mean age 47 years), 39 359 (95.4%) received at least one dose, 39 148 (94.9%) received at least two doses and 35 834 (86.8%) received three doses of a COVID-19 vaccine. Of those who received three doses, the proportions were 90.4% among those aged ≥60 years and 81.2-89.5% among other age groups; 88.7% among family physicians and 89% among specialists. 1908 physicians (4.6%) had no record of vaccination, and this included 3.4% of family physicians and 4.1% of specialists; however, 28% of this group had missing specialty information. CONCLUSIONS: In Ontario, within 14 months of COVID-19 vaccine availability, 86.8% of physicians had three doses of a COVID-19 vaccine, compared with 45.6% of the general population. Findings may signify physicians' confidence in the safety and effectiveness of COVID-19 vaccines.

The association between physical availability of cannabis retail outlets and frequent cannabis use and related health harms: a systematic review.

An increasing number of regions have or are considering legalising the sale of cannabis for adult use. Experience from tobacco and alcohol regulation has found that greater access to physical retail stores is positively associated with increased substance use and harm. Whether this association exists for cannabis is unclear. We completed a systematic review examining the association between cannabis retail store access and adverse health outcomes. We identified articles up until July 20, 2023 by searching four databases. We included studies examining the association between measures of cannabis store access and adverse outcomes: frequent or problematic cannabis use, healthcare encounters due to cannabis use (e.g., cannabis-induced psychosis), and healthcare encounters potentially related to cannabis (e.g., self-harm episodes). Results were compared by study design type, retail access measure, and by subgroups including: children, adolescents, young adults, adults, and pregnant individuals. This review was registered with PROSPERO (CRD42021281788). The search generated 5750 citations of which we included 32 studies containing 44 unique primary analyses (unique retail measure and outcome pairs). Studies come from 4 countries (United States, Canada, Netherlands and Uruguay). Among the included analyses, there were consistent positive associations between greater cannabis retail access and 1) increased healthcare service use or poison control calls directly due to cannabis (10/12 analyses; 83%) (2) increased cannabis use and cannabis-related hospitalization during pregnancy (4/4; 100%) and 3) frequent cannabis use in adults and young adults (7/11; 64%). There was no consistent positive association between greater cannabis retail and increased frequent cannabis use in adolescents (1/4; 25%), healthcare service use potentially related to cannabis (2/6; 33%) or increased adverse neonatal birth outcomes (2/7; 26.8%). There is a positive association between greater cannabis store access and increases in cannabis harm. In countries with legal cannabis, retail restrictions may reduce use and harm. Funding: Canadian Centre on Substance Use and Addiction (CCSA).

The association between alcohol retail access and health care visits attributable to alcohol for individuals with and without a history of alcohol-related health-care use.

BACKGROUND AND AIMS: Alcohol retail access is associated with alcohol use and related harms. This study measured whether this association differs for people with and without heavy and disordered patterns of alcohol use. DESIGN: The study used a repeated cross-sectional analysis of health administrative databases. SETTING, PARTICIPANTS/CASES: All residents of Ontario, Canada aged 10-105 years with universal health coverage (n = 10 677 604 in 2013) were included in the analysis. MEASUREMENTS: Quarterly rates of emergency department (ED) and outpatient visits attributable to alcohol in 464 geographic regions between 2013 and 2019 were measured. Quarterly off-premises alcohol retail access scores were calculated (average drive to the closest seven stores) for each geographic region. Mixed-effect linear regression models adjusted for area-level socio-demographic covariates were used to examine associations between deciles of alcohol retail access and health-care visits attributable to alcohol. Stratified analyses were run for individuals with and without prior alcohol-attributable health-care use in the past 2 years. FINDINGS: We included 437 707 ED visits and 505 271 outpatient visits attributable to alcohol. After adjustment, rates of ED visits were 39% higher [rate ratio (RR) = 1.39, 95% confidence interval (CI) = 1.20-1.61] and rates of outpatient visits were 49% higher (RR = 1.49, 95% CI = 1.26-1.75) in the highest versus lowest decile of alcohol access. There was a positive association between alcohol access and outpatient visits attributable to alcohol for individuals without prior health-care attributable to alcohol (RR = 1.65, 95% CI = 1.39-1.95 for the highest to lowest decile of alcohol access) but not for individuals with prior health-care attributable to alcohol (RR = 1.08, 95% CI = 0.90-1.30). There was a positive association between alcohol access and ED visits attributable to alcohol for individuals with and without prior health-care for alcohol for ED visits. CONCLUSION: In Ontario, Canada, greater alcohol retail access appears to be associated with higher rates of emergency department (ED) and outpatient health-care visits attributable to alcohol. Individuals without prior health-care for alcohol may be more susceptible to greater alcohol retail access for outpatient but not ED visits attributable to alcohol.

Cannabis-Involved Traffic Injury Emergency Department Visits After Cannabis Legalization and Commercialization.

Importance: The impact of nonmedical cannabis legalization on traffic injuries and cannabis involvement in traffic injuries is unclear. Objective: To examine changes in the number and characteristics of cannabis-involved traffic injury emergency department (ED) visits from before to after legalization and subsequent commercialization (ie, increased retail store and product availability) of cannabis in Ontario, Canada. Design, Setting, and Participants: This repeated cross-sectional study examined changes in cannabis- and alcohol-involved traffic injury ED visits in Ontario, Canada, during 3 time periods: prelegalization (January 2010-September 2018), legalization with product and retail store restrictions (October 2018-February 2020), and commercialization with new products and expanded number of stores, which coincided with the COVID-19 pandemic (March 2020-December 2021). All individuals aged 16 years and older eligible for Ontario's Universal Health Coverage were included. Season- and time-adjusted quasi-Poisson models were used to generate rate ratios with 95% CIs. Data were analyzed from March to April 2023. Main Outcomes and Measures: Quarterly counts of cannabis-involved ED visits for traffic injury. Results: There were 947 604 traffic injury ED visits, of which 426 (0.04%) had documented cannabis involvement and 7564 (0.8%) had documented alcohol involvement. Of the 418 individuals with documented cannabis involvement, 330 (78.9%) were male, 109 (25.6%) were aged 16 to 21 years (mean [SD] age at visit, 30.6 [12.0] years), and 113 (27.0%) had an ED visit or hospitalization for substance use in the 2 years before their traffic injury ED visit. Annual rates of cannabis-involved traffic injury ED visits increased 475.3% over the study period (0.18 visits per 1000 total motor vehicle collisions in 2010 to 1.01 in 2021). Over the same period, alcohol-involved traffic injury ED visits increased by 9.4% (8.03 in 2010 to 8.79 per 1000 traffic injury ED visits in 2021). Legalization with restrictions was associated with a 94% increase in the quarterly rate of cannabis involvement in traffic injury ED visits relative to prelegalization (adjusted rate ratio [aRR], 1.94; 95% CI, 1.37-2.75). Commercialization/COVID-19 was associated with a greater increase of 223% in rates (aRR, 3.23; 95% CI, 2.42-4.33). After adjusting for time trends before legalization, only commercialization/COVID-19 was associated with increased rates. Male sex (adjusted odds ratio [aOR], 3.38; 95% CI, 2.66-4.29), living in the lowest-income neighborhood (aOR, 1.92; 95% CI, 1.39-2.67), being aged 19 to 21 years (aOR, 4.67; 95% CI, 3.27-6.67), and having a prior cannabis-related ED visit (aOR, 8.03; 95% CI, 5.85-11.02) were all positively associated with cannabis involvement during a traffic injury ED visit. Conclusions and Relevance: This cross-sectional study found large increases in cannabis involvement in ED visits for traffic injury over time, which may have accelerated following nonmedical cannabis commercialization. Although the frequency of visits was rare, they may reflect broader changes in cannabis-impaired driving. Greater prevention efforts, including targeted education and policy measures, in regions with legal cannabis are indicated.

The availability and distribution of vaping retailers across Ontario neighbourhoods, 2016-2019.

OBJECTIVES: To characterize the distribution of vaping retailers and examine the association between neighbourhood income and vaping retailer availability in Ontario prior to and after regulatory changes to the vaping market in 2018. METHODS: We quantified vaping access by number of vaping retailers for 19,964 dissemination areas (DAs) in Ontario and percentage of schools near a vaping retailer. We used mixed-effects regression models to examine the associations between vaping access and neighbourhood income in 2018 and 2019. RESULTS: Between 2016 and 2019, the number of vaping retailers in Ontario increased by 22.6% (5999 to 7355), despite a mild drop from 2016 to 2018. In 2019, 59.7% of urban neighbourhoods had one or more vaping retailers within 1000 m of their geographic centre, and 79.4% of elementary, 82.8% of secondary, and 84.2% of post-secondary schools had at least one within 1000 m. Neighbourhood income was associated with access to vaping retailers, with a greater number in low-income regions. In 2019, neighbourhoods in the lowest income quintile had over twice the number of vaping retailers per capita within 1000 m compared to the highest income quintile (adjusted incidence rate ratio 2.40; 95% CI 2.24-2.58). Increases over time in access to vaping retailers did not differ by geographic region, neighbourhood income quintile, or school type. CONCLUSION: We observed a substantial increase in access to vaping retailers in Ontario including proximity to elementary and secondary schools following the 2018 provincial marketing regulations and federal nicotine regulations. Access to vaping was greatest in low-income neighbourhoods and may contribute to established inequities in vaping-related adverse events.

RéSUMé: OBJECTIFS: Caractériser la répartition des détaillants de vapotage et examiner l'association entre le revenu du quartier et la disponibilité des détaillants de vapotage en Ontario avant et après les modifications réglementaires du marché du vapotage en 2018. MéTHODES: Nous avons quantifié l'accès au vapotage selon le nombre de détaillants de vapotage pour 19 964 aires de diffusion (DA) en Ontario et le pourcentage d'écoles à proximité d'un détaillant de vapotage. Nous avons utilisé des modèles de régression à effets mixtes pour examiner les associations entre l'accès au vapotage et le revenu du quartier en 2018 et 2019. RéSULTATS: Entre 2016 et 2019, le nombre de détaillants de vapotage en Ontario a augmenté de 22,6 % (5 999 à 7 355), malgré une légère baisse de 2016 à 2018. En 2019, 59,7 % des quartiers urbains avaient un ou plusieurs détaillants de vapotage à moins de 1 000 m de leur centre géographique, et 79,4 % des écoles élémentaires, 82,8 % des écoles secondaires et 84,2 % des écoles postsecondaires en avaient au moins un détaillant à moins de 1 000 m. Le revenu du quartier était associé à l'accès aux détaillants, avec plus de détaillants dans les régions à faible revenu. En 2019, les quartiers du quintile de revenu le plus bas comptaient plus de deux fois plus de détaillants de vapotage par habitant dans un rayon de 1 000 m par rapport au quintile le plus élevé (rapport de taux d'incidence ajusté 2,40; IC à 95 % 2,24-2,58). Les augmentations au fil du temps de l'accès aux détaillants de vapotage ne différaient pas selon la région géographique, le quintile de revenu du quartier ou le type d'école. CONCLUSION: Nous avons observé une augmentation significative de l'accès aux détaillants de vapotage en Ontario, y compris la proximité des écoles primaires et secondaires à la suite des nouvelles réglementations provinciales sur le marketing et de la réglementation fédérale sur la nicotine en 2018. L'accès au vapotage était le plus élevé dans les quartiers à faible revenu et pourrait contribuer aux inégalités par rapport aux événements indésirables lié au vapotage et tabac.