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.

Estimated mortality risk and use of palliative care services among home care clients during the last 6 months of life: a retrospective cohort study.

BACKGROUND: In Canada, only 15% of patients requiring palliative care receive such services in the year before death. We describe health care utilization patterns among home care users in their last 6 months of life to inform care planning for older people with varying mortality risks and evolving care needs as they decline. METHODS: Using population health administrative data from Ontario, we performed a retrospective cohort study involving home care clients aged 50 years and older who received at least 1 interRAI (Resident Assessment Instrument) Home Care assessment between April 2018 and September 2019. We report the proportion of clients who used acute care, long-term care, and palliative home care services within 6 months of their assessment, stratified by their predicted 6-month mortality risk using a prognostic tool called the Risk Evaluation for Support: Predictions for Elder-life in their Communities Tool (RESPECT) and vital status. RESULTS: The cohort included 247 377 adults, 11.9% of whom died within 6 months of an assessment. Among decedents, 50.6% of those with a RESPECT-estimated median survival of fewer than 3 months received at least 1 nonphysician palliative home care visit before death. This proportion declined to 38.7% and 29.5% among decedents with an estimated median survival between 3 and 6 months and between 6 and 12 months, respectively. INTERPRETATION: Many older adults in Ontario do not receive any palliative home care before death. Prognostic tools such as RESPECT may improve recognition of reduced life expectancies and palliative care needs of individuals in their final years of life.

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.

Assessing the quality and value of metabolic chart data for capturing core outcomes for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.

BACKGROUND: Generating rigorous evidence to inform care for rare diseases requires reliable, sustainable, and longitudinal measurement of priority outcomes. Having developed a core outcome set for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, we aimed to assess the feasibility of prospective measurement of these core outcomes during routine metabolic clinic visits. METHODS: We used existing cohort data abstracted from charts of 124 children diagnosed with MCAD deficiency who participated in a Canadian study which collected data from birth to a maximum of 11 years of age to investigate the frequency of clinic visits and quality of metabolic chart data for selected outcomes. We recorded all opportunities to collect outcomes from the medical chart as a function of visit rate to the metabolic clinic, by treatment centre and by child age. We applied a data quality framework to evaluate data based on completeness, conformance, and plausibility for four core MCAD outcomes: emergency department use, fasting time, metabolic decompensation, and death. RESULTS: The frequency of metabolic clinic visits decreased with increasing age, from a rate of 2.8 visits per child per year (95% confidence interval, 2.3-3.3) among infants 2 to 6 months, to 1.0 visit per child per year (95% confidence interval, 0.9-1.2) among those ≥ 5 years of age. Rates of emergency department visits followed anticipated trends by child age. Supplemental findings suggested that some emergency visits occur outside of the metabolic care treatment centre but are not captured. Recommended fasting times were updated relatively infrequently in patients' metabolic charts. Episodes of metabolic decompensation were identifiable but required an operational definition based on acute manifestations most commonly recorded in the metabolic chart. Deaths occurred rarely in these patients and quality of mortality data was not evaluated. CONCLUSIONS: Opportunities to record core outcomes at the metabolic clinic occur at least annually for children with MCAD deficiency. Methods to comprehensively capture emergency care received at outside institutions are needed. To reduce substantial heterogeneous recording of core outcome across treatment centres, improved documentation standards are required for recording of recommended fasting times and a consensus definition for metabolic decompensations needs to be developed and implemented.

Potentially Inappropriate Prescribing in Long-Term Care and its Relationship With Probable Delirium.

OBJECTIVES: This study examined potentially inappropriate prescribing (PIP) of medication and its association with probable delirium among long-term care (LTC) residents in Ontario, Canada. DESIGN: Population-based cross-sectional study using provincial health administrative data, including LTC assessment data via the Resident Assessment Instrument-Minimum Dataset version 2.0 (RAI-MDS 2.0). SETTING AND PARTICIPANTS: LTC residents in Ontario between January 1, 2016, and December 31, 2019. METHODS: We used residents' first RAI-MDS 2.0 assessment in the study period as the index assessment. Probable delirium was identified via the delirium Clinical Assessment Protocol. Medication use in the 2 weeks preceding assessment was captured using medication claims data. PIP was measured using the STOPP/START criteria and 2015 Beers criteria, with residents classified as having 0, 1, 2, or 3+ instances of PIP. Relationships between PIP and probable delirium was assessed via bivariate and multivariable logistic regression models. RESULTS: The study population included 171,190 LTC residents (mean age 84.5 years, 66.8% female, 62.9% with dementia). More than half (51.8%) of residents had 1+ instances of PIP and 21% had 3+ instances of PIP according to the STOPP/START criteria; PIP prevalence was slightly lower when assessed using Beers criteria (36.5% with 1+, 11.1% with 3+). Overall, 3.7% of residents had probable delirium. The prevalence of probable delirium increased as the number of instances of PIP increased, with residents with 3+ instances of STOPP/START PIP being 1.66 times more likely (95% CI 1.56-1.77) to have probable delirium compared to those with no instances of PIP. Similar findings were observed when PIP was measured using the Beers criteria. Central nervous system (CNS)-related PIP criteria showed a stronger association with probable delirium than non-CNS-related PIP criteria. CONCLUSIONS AND IMPLICATIONS: This population-based study highlighted that PIP was highly prevalent in long-term care residents and was associated with an increased prevalence of probable delirium.

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.

Pandemic Effect on Healthcare Use and Death in Adults with Epilepsy: A Population Study.

OBJECTIVES: We conducted a population-based study using Ontario health administrative data to describe trends in healthcare utilization and mortality in adults with epilepsy during the first pandemic year (March 2020-March 2021) compared to historical data (2016-2019). We also investigated if changes in outpatient visits and diagnostic testing during the first pandemic year were associated with increased risk for hospitalizations, emergency department (ED) visits, or death. METHODS: Projected monthly visit rates (per 100,000 people) for outpatient visits, electroencephalography, magnetic resonance, computed tomography, all-cause ED visits, hospitalizations, and mortality were calculated based on historical data by fitting monthly time series autoregressive integrated moving-average models. Two-way interactions were calculated using Quasi-Poisson models. RESULTS: In adults with epilepsy during the first quarter of the pandemic, we demonstrated a reduction in all-cause outpatient visits, diagnostic testing, ED visits and hospitalizations, and a temporary increase in mortality (observed rates of 355.8 vs projected 308.8, 95% CI: 276.3-345.1). By the end of the year, outpatient visits increased (85,535.4 vs 76,620.6, 95% CI: 71,546.9-82,059.4), and most of the diagnostic test rates returned to the projected. The increase in the rate of all-cause mortality during the pandemic, compared to pre-pandemic, was greater during months with the lower frequency of diagnostic tests than months with higher frequency (interaction p-values <.0001). CONCLUSION: We described the impact of the pandemic on healthcare utilization and mortality in adults with epilepsy during the first year. We demonstrated that access to relevant diagnostic testing is likely important for this population while planning restrictions on non-urgent health services.

Prevalence and patterns of multimorbidity among linguistic groups of patients receiving home care in Ontario: a retrospective cohort study.

BACKGROUND: Prior studies have demonstrated the negative impact of language barriers on access, quality, and safety of healthcare, which can lead to health disparities in linguistic minorities. As the population ages, those with multiple chronic diseases will require increasing levels of home care and long-term services. This study described the levels of multimorbidity among recipients of home care in Ontario, Canada by linguistic group. METHODS: Population-based retrospective cohort of 510,685 adults receiving home care between April 1, 2010, to March 31, 2018, in Ontario, Canada. We estimated and compared prevalence and characteristics of multimorbidity (2 or more chronic diseases) across linguistic groups (Francophones, Anglophones, Allophones). The most common combinations and clustering of chronic diseases were examined. Logistic regression models were used to explore the main predictors of 'severe' multimorbidity (defined as the presence of five or more chronic diseases). RESULTS: The proportion of home care recipients with multimorbidity and severe multimorbidity was 92% and 44%, respectively. The prevalence of multimorbidity was slightly higher among Allophones (93.6%) than among Anglophones (91.8%) and Francophones (92.4%). However, Francophones had higher rates of cardiovascular and respiratory disease (64.9%) when compared to Anglophones (60.2%) and Allophones (61.5%), while Anglophones had higher rates of cancer (34.2%) when compared to Francophones (25.2%) and Allophones (24.3%). Relative to Anglophones, Allophones were more likely to have severe multimorbidity (adjusted OR = 1.04, [95% CI: 1.02-1.06]). CONCLUSIONS: The prevalence of multimorbidity among Ontarians receiving home care services is high; especially for whose primary language is a language other than English or French (i.e., Allophones). Understanding differences in the prevalence and characteristics of multimorbidity across linguistic groups will help tailor healthcare services to the unique needs of patients living in minority linguistic situations.

Long-term cognitive impairment after probable delirium in long-term care residents: A population-based retrospective cohort study.

BACKGROUND: The impact of delirium on cognition has not been well-studied in long-term care (LTC) residents. This study examined changes in cognition 1 year after a probable delirium episode among LTC residents, compared to LTC residents without probable delirium. We also evaluated whether the relationship between probable delirium and cognitive change differed according to a diagnosis of dementia. METHODS: We conducted a population-based retrospective cohort study using linked health administrative data. The study population included adults aged 65+ residing in LTC in Ontario, Canada and assessed via the Resident Assessment Instrument-Minimum Dataset between January 1, 2016 and December 31, 2018. Probable delirium was ascertained via the delirium Clinical Assessment Protocol on the index assessment. Cognition was measured quarterly using the Cognitive Performance Scale (range 0-6, higher values indicate greater impairment). Cognitive decline up to 1 year after index was evaluated using multivariable proportional odds regression models. RESULTS: Of 92,005 LTC residents, 2816 (3.1%) had probable delirium at index. Residents with probable delirium had an increased odds of cognitive decline compared to those without probable delirium, with adjusted odds ratios of 1.64 (95% confidence interval [CI] 1.35-1.99), 1.56 (95% CI 1.34-1.85), 1.57 (95% CI 1.32-1.86) and 1.50 (95% CI 1.25-1.80) after 1-3, 4-6, 7-9, and 10-12 months of follow-up. Residents with probable delirium and a comorbid dementia diagnosis had the highest adjusted odds of cognitive decline (adjusted odds ratio 5.57, 95% CI 4.79-6.48) compared to those without probable delirium or dementia. Residents with probable delirium were also more likely to die within 1 year than those without probable delirium (52.5% vs. 23.4%). CONCLUSIONS: Probable delirium is associated with increased mortality and worsened cognition in LTC residents that is sustained months after the probable delirium episode. Efforts to prevent delirium in this population may help limit these adverse effects.

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.

Transition to Schizophrenia Spectrum Disorder Following Emergency Department Visits Due to Substance Use With and Without Psychosis.

Importance: Episodes of substance-induced psychosis are associated with increased risk of developing a schizophrenia spectrum disorder. However, there are limited data on the transition risk for substance use without psychosis. Objectives: To quantify the risk of transition to schizophrenia spectrum disorder following an incident emergency department (ED) visit for (1) substance-induced psychosis and (2) substance use without psychosis and to explore factors associated with transition. Design, Settings, and Participants: A population-based retrospective cohort study (January 2008 to March 2022) of all individuals, aged 14 to 65 years, in Ontario, Canada, with no history of a psychotic disorder. Individuals with incident ED visits for substance use with and without psychosis were compared with members of the general population. Main Outcomes and Measures: Transition to schizophrenia spectrum disorder using a chart-validated algorithm. Associations between ED visits for substance use and subsequent transition were estimated using cause-specific hazard models. Results: The study included 9 844 497 individuals, aged 14 to 65 years (mean [SD] age, 40.2 [14.7] years; 50.2% female) without a history of psychosis. There were 407 737 individuals with an incident ED visit for substance use, of which 13 784 (3.4%) ED visits were for substance-induced psychosis. Individuals with substance-induced psychosis were at a 163-fold (age- and sex-adjusted hazard ratio [aHR], 163.2; 95% CI, 156.1-170.5) increased risk of transitioning, relative to the general population (3-year risk, 18.5% vs 0.1%). Individuals with an ED visit for substance use without psychosis had a lower relative risk of transitioning (aHR, 9.8; 95% CI, 9.5-10.2; 3-year risk, 1.4%), but incurred more than 3 times the absolute number of transitions (9969 vs 3029). Cannabis use had the highest transition risk among visits with psychosis (aHR, 241.6; 95% CI, 225.5-258.9) and the third-highest risk among visits without psychosis (aHR, 14.3; 95% CI, 13.5-15.2). Younger age and male sex were associated with a higher risk of transition, and the risk of male sex was greater in younger compared with older individuals, particularly for cannabis use. Conclusions and Relevance: The findings of this cohort study suggest that ED visits for substance use were associated with an increased risk of developing a schizophrenia spectrum disorder. Although substance-induced psychoses had a greater relative transition risk, substance use without psychosis was far more prevalent and resulted in a greater absolute number of transitions. Several factors were associated with higher transition risk, with implications for counseling and early intervention.

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.

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.

Physician benzodiazepine self-use prior to and during the COVID-19 pandemic in Ontario, Canada: a population-level cohort study.

OBJECTIVES: The aim of this study was to investigate physician benzodiazepine (BZD) self-use pre-COVID-19 pandemic and to examine changes in BZD self-use during the first year of the pandemic. DESIGN: Population-based retrospective cohort study using linked routinely collected administrative health data comparing the first year of the pandemic to the period before the pandemic. SETTING: Province of Ontario, Canada between March 2016 and March 2021. PARTICIPANTS: INTERVENTION: Onset of the COVID-19 pandemic in March 2020. OUTCOMES MEASURES: The primary outcome measure was the receipt of one or more prescriptions for BZD, which was captured via the Narcotics Monitoring System. RESULTS: In a cohort of 30 798 physicians (mean age 42, 47.8% women), we found that during the year before the pandemic, 4.4% of physicians had 1 or more BZD prescriptions. Older physicians (6.8% aged 50+ years), female physicians (5.1%) and physicians with a prior mental health (MH) diagnosis (12.4%) were more likely than younger (3.7% aged <50 years), male physicians (3.8%) and physicians without a prior MH diagnosis (2.9%) to have received 1 or more BZD prescriptions. The first year of the COVID-19 pandemic was associated with a 10.5% decrease (adjusted OR (aOR) 0.85, 95% CI: 0.80 to 0.91) in the number of physicians with 1 or more BZD prescriptions compared with the year before the pandemic. Female physicians were less likely to reduce BZD self-use (aORfemale=0.90, 95% CI: 0.83 to 0.98) compared with male physicians (aORmale=0.79, 95% CI: 0.72 to 0.87, pinteraction=0.046 during the pandemic. Physicians presenting with an incident MH visit had higher odds of filling a BZD prescription during COVID-19 compared with the prior year. CONCLUSIONS: Physicians' BZD prescriptions decreased during the first year of the COVID-19 pandemic in Ontario, Canada. These findings suggest that previously reported increases in mental distress and MH visits among physicians during the pandemic did not lead to greater self-use of BZDs.

Changes in health service use due to alcohol during the COVID-19 pandemic among individuals with and individuals without pre-existing alcohol-related medical diagnoses.

OBJECTIVE: To compare changes in outpatient and acute care visits due to alcohol during the COVID-19 pandemic between individuals with and those without a history of alcohol-related health service use (AHSU). METHODS: We conducted a cross-sectional analysis of health administrative data in Ontario, Canada. The Ontario population was stratified into those with and those without 1+ health service encounter(s) due to alcohol in the past 2 years. We compared age- and sex-standardized rates of alcohol-related outpatient visits, emergency department (ED) visits, and hospitalizations during the first 15 months of the pandemic (March 2020-May 2021) to those during the same 15-month period prior to the pandemic (March 2018-May 2019). RESULTS: Of 13,450,750 eligible Ontarians on March 11, 2022, 129,434 (1.0%) had AHSU in the previous 2 years. Overall, rates of alcohol-related outpatient visits and hospitalizations increased, while rates of alcohol-related ED visits decreased during the pandemic. There was a similar relative increase in rates of alcohol-related outpatient visits and hospitalizations between those with and those without prior AHSU. However, the absolute increase in rates of alcohol-related outpatient visits and hospitalizations was higher among those with prior AHSU (outpatient rate difference (RD) per 10,000 population: 852.3, 95% confidence interval (CI): 792.7, 911.9; inpatient RD: 26.0, 95% CI: -2.3, 54.2) than among those without (outpatient RD: 6.5, 95% CI: 6.0, 6.9; inpatient RD: 0.4, 95% CI: 0.2, 0.7). CONCLUSION: Rates of alcohol-related outpatient and inpatient care increased during the COVID-19 pandemic, and high rate of recurrent harm among individuals with pre-pandemic AHSU was an important contributor to this trend.

RéSUMé: OBJECTIF: Comparer les changements dans consultations externes et les consultations en soins actifs liées à l'alcool pendant la pandémie de COVID-19 chez les personnes avec et chez celles sans antécédents d'utilisation des services de santé liée à l'alcool (USSLA). MéTHODE: Nous avons effectué une analyse transversale des données administratives sur la santé de l'Ontario, au Canada. Nous avons stratifié la population ontarienne selon la présence (1+) ou l'absence de contacts avec les services de santé pour des raisons liées à l'alcool au cours des deux années antérieures. Nous avons comparé les taux de consultations externes, de consultations à l'urgence et d'hospitalisations liées à l'alcool, standardisés pour l'âge et le sexe, au cours des 15 premiers mois de la pandémie (mars 2020­mai 2021) aux taux correspondants pour la même période de 15 mois avant la pandémie (mars 2018­mai 2019). RéSULTATS: Sur les 13 450 750 Ontariens et Ontariennes admissibles le 11 mars 2022, 129 434 (1,0 %) avaient utilisé les services de santé pour des raisons liées à l'alcool au cours des deux années antérieures. Dans l'ensemble, les taux de consultations externes et d'hospitalisations liées à l'alcool ont augmenté, tandis que les taux de consultations à l'urgence liées à l'alcool ont diminué pendant la pandémie. Il y a eu une augmentation relative semblable des taux de consultations externes et d'hospitalisations liées à l'alcool entre les personnes avec et sans antécédents d'USSLA. Par contre, l'augmentation absolue des taux de consultations externes et d'hospitalisations liées à l'alcool a été plus élevée chez les personnes ayant des antécédents d'USSLA (différence de taux [DT] de consultations externes pour 10 000 habitants : 852,3; intervalle de confiance de 95 % [IC] : 792,7, 911,9; DT d'hospitalisations : 26,0; IC de 95 % : -2,3, 54,2) que chez les personnes sans antécédents d'USSLA (DT de consultations externes : 6,5; IC de 95 % : 6,0, 6,9; DT d'hospitalisations : 0,4; IC de 95 % : 0,2, 0,7). CONCLUSION: Les taux de consultations externes et d'hospitalisations liées à l'alcool ont augmenté pendant la pandémie de COVID-19, et les taux élevés de méfaits récurrents chez les personnes ayant utilisé les services de santé pour des raisons liées à l'alcool avant la pandémie ont beaucoup contribué à cette tendance.

Outpatient Mental Health Follow-up and Recurrent Self-harm and Suicide Among Patients Admitted to the ICU for Self-harm: A Population-based Cohort Study.

BACKGROUND: Patients surviving an ICU admission for deliberate self-harm are at high risk of recurrent self-harm or suicide after discharge. It is unknown whether mental health follow-up after discharge (with either a family physician or psychiatrist) reduces this risk. RESEARCH QUESTION: What is the association between mental health follow-up after discharge and recurrent self-harm among patients admitted to the ICU for intentional self-harm? STUDY DESIGN AND METHODS: Population-based cohort study of consecutive adults (≥ 18 years of age) from Ontario, Canada, who were admitted to ICU because of intentional self-harm between 2009 and 2017. We categorized patients according to follow-up, with 'early follow-up' indicating 1 to 21 days after discharge, 'late follow-up' indicating 22 to 60 days after discharge, and 'no follow-up' indicating no follow-up within 60 days of discharge. We conducted analyses using a cause-specific extended Cox regression model to account for varying time for mental health follow-up relative to the outcomes of interest. The primary outcome was recurrent ICU admission for self-harm within 1 year of discharge. RESULTS: We included 9,569 consecutive adults admitted to the ICU for deliberate self-harm. Compared with receiving no mental health follow-up, both early follow-up (hazard ratio [HR], 1.37; 95% CI, 1.07-1.75) and late follow-up (HR, 1.69; 95% CI, 1.22-2.35) were associated with increased risk in recurrent ICU admission for self-harm. As compared with no follow-up, neither early follow-up (HR, 1.10; 95% CI, 0.70-1.73) nor late follow-up (HR, 1.54; 95% CI, 0.84-2.83) were associated with increased risk of death by suicide. INTERPREATION: Among adults admitted to the ICU for deliberate self-harm, mental health follow-up after discharge was not associated with reduced risk of recurrent ICU admission for self-harm or death resulting from suicide, and patients seeking outpatient follow-up may be those at highest risk of these outcomes. Future research should focus on additional and novel methods of risk mitigation in this vulnerable population.

Trends in outpatient and inpatient visits for separate ambulatory-care-sensitive conditions during the first year of the COVID-19 pandemic: a province-based study.

Background: The COVID-19 pandemic led to global disruptions in non-urgent health services, affecting health outcomes of individuals with ambulatory-care-sensitive conditions (ACSCs). Methods: We conducted a province-based study using Ontario health administrative data (Canada) to determine trends in outpatient visits and hospitalization rates (per 100,000 people) in the general adult population for seven ACSCs during the first pandemic year (March 2020-March 2021) compared to previous years (2016-2019), and how disruption in outpatient visits related to acute care use. ACSCs considered were chronic obstructive pulmonary disease (COPD), asthma, angina, congestive heart failure (CHF), hypertension, diabetes, and epilepsy. We used time series auto-regressive integrated moving-average models to compare observed versus projected rates. Results: Following an initial reduction (March-May 2020) in all types of visits, primary care outpatient visits (combined in-person and virtual) returned to pre-pandemic levels for asthma, angina, hypertension, and diabetes, remained below pre-pandemic levels for COPD, and rose above pre-pandemic levels for CHF (104.8 vs. 96.4, 95% CI: 89.4-104.0) and epilepsy (29.6 vs. 24.7, 95% CI: 22.1-27.5) by the end of the first pandemic year. Specialty visits returned to pre-pandemic levels for COPD, angina, CHF, hypertension, and diabetes, but remained above pre-pandemic levels for asthma (95.4 vs. 79.5, 95% CI: 70.7-89.5) and epilepsy (53.3 vs. 45.6, 95% CI: 41.2-50.5), by the end of the year. Virtual visit rates increased for all ACSCs. Among ACSCs, reductions in hospitalizations were most pronounced for COPD and asthma. CHF-related hospitalizations also decreased, albeit to a lesser extent. For angina, hypertension, diabetes, and epilepsy, hospitalization rates reduced initially, but returned to pre-pandemic levels by the end of the year. Conclusion: This study demonstrated variation in outpatient visit trends for different ACSCs in the first pandemic year. No outpatient visit trends resulted in increased hospitalizations for any ACSC; however, reductions in rates of asthma, COPD, and CHF hospitalizations persisted.

Rurality, Socioeconomic Status, and Residence in Environmental Risk Areas Associated with Increased Lyme Disease Incidence in Ontario, Canada: A Case-Control Study.

Background: Lyme disease (LD) is the most common tick-borne illness in North America. LD is acquired through exposure to the tick vector, Ixodes scapularis, known as the blacklegged tick. In Canada, LD is rapidly emerging, with the establishment of I. scapularis in many newly endemic regions posing a growing risk to local communities. In the Canadian context, many environmental and socioeconomic risk factors for human LD infection are yet to be ascertained and the degree of risk associated with residential and community exposure to ticks is not well known. Methods: We conducted a matched case-control study in southeastern Ontario, using LD patient data from provincial laboratory databases and uninfected population controls from 2014 to 2018. We aimed to identify area-level risk factors for LD and associations with residence in environmental risk areas, defined as areas with high model-predicted probability of I. scapularis occurrence, using the neighborhood dissemination area as the unit of analysis. Results: Using multivariable conditional logistic regression analysis, we identified that patients with LD had higher odds (odds ratio, OR; 95% confidence interval, CI) of living in neighborhoods with high probability of tick occurrence in the environment (OR = 2.2; 95% CI: 2.0-2.5), low walkability (OR = 1.6; 95% CI: 1.2-2.1), low material deprivation (OR = 1.4; 95% CI: 1.2-1.7), and low ethnic concentration (OR = 8.1; 95% CI: 6.7-9.9). We also found that the odds of LD infection for individuals residing in environmental risk areas was highest for those living in public health units (PHUs) with <250,000 population (OR = 3.0; 95% CI: 2.4-3.9) compared to those living in PHUs with >1,000,000 population (OR = 1.5; 95% CI: 1.1-2.1). Conclusion: This study shows that odds of human LD infection in Ontario, Canada is higher in less urbanized areas with higher socioeconomic status and indicates that exposure to ticks around the home residence or neighborhood is linked to increased odds of LD.