Changes in the incidence of cannabis-related disorders after the Cannabis Act and the COVID-19 pandemic in Québec, Canada.

BACKGROUND: The Canadian Cannabis Act (CCA, implemented in October 2018) and the COVID-19 pandemic (April 2020) might have contributed to cannabis-related harms in Québec, known for its stringent cannabis legal framework. We explored changes in incidence rates of cannabis-related disorders (CRD) diagnoses associated with these events in Québec. METHODS: We utilized linked administrative health data to identify individuals aged 15 year+ newly diagnosed with CRD during hospitalizations, emergency, and outpatients clinics across Québec, from January 2010 and March 2022 (147 months). Interrupted time-series analyses (ITSA) assessed differences (as percentage changes) in sex- and age-standardized, and sex-stratified, monthly incidence rates (per 100,000 population) attributed to the CCA and the COVID-19 pandemic, compared to counterfactual scenarios where pre-events trends would continue unchanged. RESULTS: The overall monthly mean rates of incident diagnoses nearly doubled from the pre-CCA period (1.56 per 100,000 population) to the COVID-19 pandemic period (3.02 per 100,000 population). ITSA revealed no statistically significant level or slope changes between adjacent study periods, except for a decrease in the slope of incidence rates among males by 1.84 % (95 % CI -3.41 to -0.24) during the COVID-19 pandemic compared to the post-CCA period. During the post-CCA period, the trends of incidence rates in the general and male populations grew significantly by 1.22 % (95 % CI 0.08 to 2.35) and 1.44 % (0.04 to 2.84) per month, respectively. Similarly significant increases were observed for the general and female populations during the COVID-19 pandemic, with monthly rates rising by 1.43 % (95 % CI 0.75 to 2.12) and 1.75 % (95 % CI 0.13 to 3.37), respectively. These increases more than doubled pre-CCA rates. CONCLUSIONS: The incidence rates of CRD diagnoses across Québec appears to have increased following the implementation of the CCA and during the COVID-19 pandemic. Our findings echo public health concerns regarding potential cannabis-related harms and are consistent with previous Canadian studies.

Changes in prenatal cannabis-related diagnosed disorders after the Cannabis Act and the COVID-19 pandemic in Quebec, Canada.

BACKGROUND AND AIMS: Public health concerns regarding pregnant women's health after the enactment of the Cannabis Act in Canada (CAC) (a law that allowed non-medical cannabis use), and the potential impact of the COVID-19 pandemic, call for a contemporary assessment of these two events. Our study measured associations between the CAC, the COVID-19 pandemic and the monthly prevalence rates of cannabis-, all drug- and alcohol-related diagnosed disorders among pregnant women in the province of Quebec. DESIGN, SETTING AND PARTICIPANTS: This was a quasi-experimental design applying an interrupted time-series methodology in the province of Quebec, Canada. The participants were pregnant women aged 15-49 years, between January 2010 and July 2022. MEASUREMENTS: Administrative health data from the Québec Integrated Chronic Disease Surveillance System were used to classify pregnant women according to cannabis-, all drug (excluding cannabis)- and alcohol-related disorders. The CAC (October 2018) and the COVID-19 pandemic (April 2020) were evaluated as (1) slope changes and (2) level changes. Cannabis-, all drug (excluding cannabis)- and alcohol-related disorders were measured by total monthly age-standardized monthly prevalence rate of each disorder for pregnant women aged 15-49 years. FINDINGS: Before the CAC, the prevalence rate of cannabis-related diagnosed disorders significantly increased each month by 0.5% [95% confidence interval (CI) = 0.3-0.6] in the pregnant population. After the CAC, there were significant increases of 24% (95% CI = 1-53) of cannabis-related diagnosed disorders. No significant changes were observed for all drug (excluding cannabis)- and alcohol-related diagnosed disorders associated with the CAC. A non-significant decrease of 20% (95% CI = -38 to 3) was observed during the COVID-19 pandemic in alcohol-related disorders. CONCLUSIONS: The monthly incidence rates of diagnosed cannabis-related disorders in pregnant women in Quebec increased significantly following the enactment of the Cannabis Act in Canada. Diagnoses of all drug (excluding cannabis)- and alcohol-related disorders remained relatively stable.

Rural-Urban Differences in Healthcare Use in Persons With Dementia Between 2000 and 2019: A Quebec Population-Based Study.

Background: Rural persons with dementia face medical services gaps. This study compares the health service utilization of rural and urban community-dwelling individuals with incident dementia. Methods: This study used a repeated annual cross-sectional cohort design spanning a period from 2000 to 2019 analyzing age-adjusted rates for 20 indicators of service use and mortality one year after diagnosis in Quebec administrative databases. Results: Of 237,259 persons, 20.1% were rural. Most rural persons had more emergency department visits and hospitalizations, shorter stays, less alternate level of care and fewer family physicians' and cognition specialists' visits. All groups had similar long-term care and mortality rates. Conclusion: Policy implications of these disparities are discussed.

Explainable artificial intelligence models for predicting risk of suicide using health administrative data in Quebec.

Suicide is a complex, multidimensional event, and a significant challenge for prevention globally. Artificial intelligence (AI) and machine learning (ML) have emerged to harness large-scale datasets to enhance risk detection. In order to trust and act upon the predictions made with ML, more intuitive user interfaces must be validated. Thus, Interpretable AI is one of the crucial directions which could allow policy and decision makers to make reasonable and data-driven decisions that can ultimately lead to better mental health services planning and suicide prevention. This research aimed to develop sex-specific ML models for predicting the population risk of suicide and to interpret the models. Data were from the Quebec Integrated Chronic Disease Surveillance System (QICDSS), covering up to 98% of the population in the province of Quebec and containing data for over 20,000 suicides between 2002 and 2019. We employed a case-control study design. Individuals were considered cases if they were aged 15+ and had died from suicide between January 1st, 2002, and December 31st, 2019 (n = 18339). Controls were a random sample of 1% of the Quebec population aged 15+ of each year, who were alive on December 31st of each year, from 2002 to 2019 (n = 1,307,370). We included 103 features, including individual, programmatic, systemic, and community factors, measured up to five years prior to the suicide events. We trained and then validated the sex-specific predictive risk model using supervised ML algorithms, including Logistic Regression (LR), Random Forest (RF), Extreme Gradient Boosting (XGBoost) and Multilayer perceptron (MLP). We computed operating characteristics, including sensitivity, specificity, and Positive Predictive Value (PPV). We then generated receiver operating characteristic (ROC) curves to predict suicides and calibration measures. For interpretability, Shapley Additive Explanations (SHAP) was used with the global explanation to determine how much the input features contribute to the models' output and the largest absolute coefficients. The best sensitivity was 0.38 with logistic regression for males and 0.47 with MLP for females; the XGBoost Classifier with 0.25 for males and 0.19 for females had the best precision (PPV). This study demonstrated the useful potential of explainable AI models as tools for decision-making and population-level suicide prevention actions. The ML models included individual, programmatic, systemic, and community levels variables available routinely to decision makers and planners in a public managed care system. Caution shall be exercised in the interpretation of variables associated in a predictive model since they are not causal, and other designs are required to establish the value of individual treatments. The next steps are to produce an intuitive user interface for decision makers, planners and other stakeholders like clinicians or representatives of families and people with live experience of suicidal behaviors or death by suicide. For example, how variations in the quality of local area primary care programs for depression or substance use disorders or increased in regional mental health and addiction budgets would lower suicide rates.

Sex Differences in Healthcare Utilization in Persons Living with Dementia Between 2000 and 2017: A Population-Based Study in Quebec, Canada.

Objectives: Describe sex differences in healthcare utilization and mortality in persons with new dementia in Quebec, Canada. Methods: We conducted a repeated cohort study from 2000 to 2017 using health administrative databases. Community-dwelling persons aged 65+ with a new diagnosis of dementia were included. We measured 23 indicators of healthcare use across five care settings: ambulatory care, pharmacological care, acute hospital care, long-term care, and mortality. Clinically meaningful sex differences in age-standardized rates were determined graphically through expert consultations. Results: Women with dementia had higher rates of ambulatory care and pharmacological care, while men with dementia had higher acute hospital care, admission to long-term care, and mortality. There was no meaningful difference in visits to cognition specialists, antipsychotic prescriptions, and hospital death. Discussion: Men and women with dementia demonstrate differences in healthcare utilization and mortality. Addressing these differences will inform decision-makers, care providers and researchers and guide more equitable policy and interventions in dementia care.

ADHD medications use and risk of mortality and unintentional injuries: a population-based cohort study.

We assessed the association between the use of medications for attention-deficit/hyperactivity disorder (ADHD) and the risk of all-cause mortality and unintentional injuries leading to emergency department (ED) or hospital admission in individuals aged ≤24 years with ADHD. We conducted a population-based retrospective cohort study between 2000 and 2021 using Quebec health administrative data. Individuals were followed from the first ADHD diagnosis or ADHD medication claim until turning 25, death, or study end. Exposure was defined as mutually exclusive episodes of ADHD medication use and/or coverage under the public provincial drug plan (PDP): 1) covered and not treated with ADHD medication; 2) covered and treated with ADHD medication; and 3) not covered under the PDP. The risk of all-cause mortality and unintentional injuries associated with exposure episodes was estimated using multivariable survival analyses. The cohort included n = 217 192 individuals aged 1-24 years with a male to female ratio of close to 2:1. Compared to non-medication use, episodes of ADHD medication use, overall, were associated with reduced all-cause mortality (adjusted hazard ratio, aHR 0.61, 95% CI 0.48-0.76) and unintentional injury leading to ED (0.75, 0.74-0.77) or hospitalisation (0.71, 0.68-0.75). Episodes of stimulants were associated with a lower risk of all-cause mortality and reduced risk of unintentional injuries, while episodes with non-stimulants and with both stimulants and non-stimulants concomitantly were associated with reduced risk of unintentional injuries, but not of all-cause mortality. Although residual confounding cannot be excluded, stimulants may have a protective effect in terms of risk of all-cause mortality and both stimulants and non-stimulants for ADHD may reduce the risk of unintentional injuries. The findings of the current study should inform clinical decision making on the choice of starting a pharmacological treatment for ADHD, when a balance needs to be struck between expected benefits and possible risks.

Change in intention and hesitancy regarding COVID-19 vaccines in a cohort of adults in Quebec during the pandemic.

Although COVID-19 vaccine uptake was high in Quebec for the primary series, vaccine acceptance decreased for the subsequent booster doses. This article presents the evolution of vaccine intention, self-reported vaccination behaviors, and vaccine hesitancy over 2 years. A series of cross-sectional surveys were conducted in Quebec between March 2020 and March 2023, with a representative sample of 3,330 adults recruited biweekly via a Web panel. Panelists could have answered multiple times over the course of the project. A cohort of respondents was created to assess how attitudes and behaviors about COVID-19 vaccines evolved. Descriptive statistics and multivariate logistic regressions were performed. Among the 1,914 individuals with no or low intention of getting vaccinated in Fall 2021 (Period 1), 1,476 (77%) reported having received at least two doses in the Winter 2023 (Period 2). Not believing in conspiracy theory (OR = 2.08, 95% CI: 1.65-2.64), being worried about catching COVID-19 (OR = 2.12, 95% CI: 1.65-2.73) and not living in a rural area (ORs of other areas are 2.27, 95% CI: 1.58-3.28; 1.66, 95% CI: 1.23-2.26; 1.82 95% CI: 1.23-2.73) were the three main factors associated with being vaccinated at Period 2. Among the 11,117 individuals not hesitant at Period 1, 1,335 (12%) became hesitant at Period 2. The three main factors significantly associated with becoming vaccine hesitant were the adherence to conspiracy theories (OR = 2.28, 95% CI: 1.95-2.66), being a female (OR = 1.67, 95% CI: 1.48-1.90) and being younger than 65 years old (the ORs for 18-34, 35-49, and 50-64 compared with 65 and over are 2.82, 95% CI: 2.32-3.44; 2.39, 95% CI: 2.00-2.86 and 1.82, 95% CI: 1.55-2.15 respectively). As the pandemic is over, monitoring the evolution of vaccine attitudes and uptake will be important.

Predictors of Physician Follow-Up Care Among Patients Affected by an Incident Mental Disorder Episode in Quebec (Canada).

OBJECTIVES: This study identified predictors of prompt (1+ outpatient physician consultations/within 30 days), adequate (3+/90 days) and continuous (5+/365 days) follow-up care from general practitioners (GPs) or psychiatrists among patients with an incident mental disorder (MD) episode. METHODS: Study data were extracted from the Quebec Integrated Chronic Disease Surveillance System (QICDSS), which covers 98% of the population eligible for health-care services under the Quebec (Canada) Health Insurance Plan. This observational epidemiological study investigating the QICDSS from 1 April 1997 to 31 March 2020, is based on a 23-year patient cohort including 12+ years old patients with an incident MD episode (n = 2,670,133). Risk ratios were calculated using Robust Poisson regressions to measure patient sociodemographic and clinical characteristics, and prior service use, which predicted patients being more or less likely to receive prompt, adequate, or continuous follow-up care after their last incident MD episode, controlling for previous MD episodes, co-occurring disorders, and years of entry into the cohort. RESULTS: A minority of patients, and fewer over time, received physician follow-up care after an incident MD episode. Women; patients aged 18-64; with depressive or bipolar disorders, co-occurring MDs-substance-related disorders (SRDs) or physical illnesses; those receiving previous GP follow-up care, especially in family medicine groups; patients with higher prior continuity of GP care; and previous high users of emergency departments were more likely to receive follow-up care. Patients living outside the Montreal metropolitan area; those without prior MDs; patients with anxiety, attention deficit hyperactivity, personality, schizophrenia and other psychotic disorders, or SRDs were less likely to receive follow-up care. CONCLUSION: This study shows that vulnerable patients with complex clinical characteristics and those with better previous GP care were more likely to receive prompt, adequate or continuous follow-up care after an incident MD episode. Overall, physician follow-up care should be greatly improved.

Psychotropic medication use pre and post-diagnosis of cluster B personality disorder: a Quebec's health services register cohort.

Background: Cluster B personality disorders (PDs) are considered some of the most severe mental health conditions. Scarce evidence exists about the real-world utilization of psychotropics for cluster B PD individuals. Objective: We aimed to uncover trends and patterns of psychotropic medication use among individuals diagnosed with cluster B PD in the year before and after their diagnosis and to identify factors associated with medication use in a large cohort of individuals newly diagnosed with cluster B PDs. Methods: We conducted a population-based observational study using Quebec's health services register. We identified Quebec residents aged ≥14 years and insured with the provincial drug plan with a first diagnosis of cluster B PD recorded between April 1, 2002, and March 31, 2019. Cluster B PD was defined with ICD-9/10 diagnostic codes. We retrieved all claims for the main psychotropic medication classes: antipsychotics, antidepressants, anxiolytics, mood stabilizers, and attention-deficit/hyperactivity disorder (ADHD) medications. We calculated the proportion of individuals exposed to these medication classes and analyzed trends over the years using robust Poisson regression models, adjusting for potential confounders. We used robust Poisson regression to identify factors associated with medication class use. Results: We identified 87,778 new cases of cluster B PD, with a mean age of 44.5 years; 57.5% were women. Most frequent psychiatric comorbidities in the five years before cluster B PD diagnosis were depression (50.9%), anxiety (49.7%), and psychotic disorders (37.5%). Most individuals (71.0%) received at least one psychotropic during the year before cluster B PD diagnosis, and 78.5% received at least one of these medications in the subsequent year. The proportion of users increased after the diagnosis for antidepressants (51.6-54.7%), antipsychotics (35.9-45.2%), mood stabilizers (14.8-17.0%), and ADHD medications (5.1-5.9%), and remained relatively stable for anxiolytics (41.4-41.7%). Trends over time showed statistically significant increased use of antipsychotics and ADHD medications, decreased use of anxiolytics and mood stabilizers, and a stable use of antidepressants. Conclusion: Psychotropic medication use is highly prevalent among cluster B PD individuals. We observed an increase in medication use in the months following the diagnosis, particularly for antipsychotics, antidepressants, and mood stabilizers.

Impact of chronic comorbidities on hospitalization, intensive care unit admission and death among adult vaccinated and unvaccinated COVID-19 confirmed cases during the Omicron wave.

Background: Comorbidities are important risk factors of severe COVID-19 complications. Their impact during the Omicron wave among vaccinated and unvaccinated COVID-19 cases is not well documented. Purpose: The objective of this study was to estimate the association between the number of comorbidities and the risk of hospitalization, intensive care unit (ICU) admission, and death among vaccinated and unvaccinated confirmed adult COVID-19 cases during the Omicron wave. Research Design and Study sample: We performed a cohort study of COVID-19 adult cases of primo-infection occurring during the Omicron wave, from December 5, 2021 to January 9, 2022 using surveillance database of the province of Québec, Canada. The database included all laboratory-confirmed cases in the province and the related information on 21 pre-existing comorbidities, hospitalization, ICU admission, death related to COVID-19 and vaccination status. Analysis: We performed a robust Poisson regression model to estimate the impact of the number of comorbidities on each complication by vaccination status adjusted for age, sex, socioeconomic status, and living environment. Results: We observed that the risk of complication increased for each additional comorbidity in both vaccinated and unvaccinated individuals and that this risk was systematically higher among unvaccinated individuals. Compared with vaccinated individuals without comorbidities (reference group), the risks of hospitalization, ICU admission, and death were respectively: 9X (95% CI [7.77-12.01]), 13X (95% CI [8.74-18.87]), and 12X (95% CI [7.57-18.91]) higher in vaccinated individuals with ≥3 comorbidities; 22X (95% CI [19.07-25.95]), 45X (95% CI [29.06-69.67]) and 38X (95% CI [23.62-61.14]) higher in unvaccinated individuals with ≥3 comorbidities. Conclusion: Our results support the importance of promoting vaccination in all individuals, and especially those with pre-existing medical conditions, to reduce severe complications, even during the Omicron wave.

Psychiatric and non-psychiatric polypharmacy among older adults with schizophrenia: Trends from a population-based study between 2000 and 2016.

Background: Schizophrenia is a severe psychiatric disorder associated with multiple psychiatric and non-psychiatric comorbidities. As adults with schizophrenia age, they may use many medications, i.e., have polypharmacy. While psychiatric polypharmacy is well documented, little is known about trends and patterns of global polypharmacy. This study aimed to draw a portrait of polypharmacy among older adults with schizophrenia from 2000 to 2016. Methods: This population-based cohort study was conducted using the data of the Quebec Integrated Chronic Disease Surveillance System of the National Institute of Public Health of Quebec to characterize recent trends and patterns of medication use according to age and sex. We identified all Quebec residents over 65 years with an ICD-9 or ICD-10 diagnosis of schizophrenia between 2000 and 2016. We calculated the total number of medications used by every individual each year and the age-standardized proportion of individuals with polypharmacy, as defined by the usage of 5+, 10+, 15+, and 20+ different medications yearly. We identified the clinical and socio-demographic factors associated with polypharmacy using robust Poisson regression models considering the correlation of the responses between subjects and analyzed trends in the prevalence of different degrees of polypharmacy. Results: From 2000 to 2016, the median number of medications consumed yearly rose from 8 in 2000 to 11 in 2016. The age-standardized proportion of people exposed to different degrees of polypharmacy also increased from 2000 to 2016: 5+ drugs: 76.6%-89.3%; 10+ drugs: 36.9%-62.2%; 15+: 13.3%-34.4%; 20+: 3.9%-14.4%. Non-antipsychotic drugs essentially drove the rise in polypharmacy since the number of antipsychotics remained stable (mean number of antipsychotics consumed: 1.51 in 2000 vs. 1.67 in 2016). In the multivariate regression, one of the main clinically significant factor associated with polypharmacy was the number of comorbidities (e.g., Polypharmacy-10+: RR[2 VS. 0-1] = 1.4; 99% IC:1.3-1.4, RR[3-4] = 1.7 (1.7-1.8); RR[5+] = 2.1 (2.1-2.2); Polypharmacy-15+: RR[2 VS 0-1] = 1.6; 99% IC:1.5-1.7, RR[3-4] = 2.5 (2.3-2.7); RR[5+] = 4.1 (3.8-4.5). Conclusion: There was a noticeable increase in polypharmacy exposure among older adults with schizophrenia in recent years, mainly driven by non-antipsychotic medications. This raises concerns about the growing risks for adverse effects and drug-drug interactions in this vulnerable population.

A case-control study on predicting population risk of suicide using health administrative data: a research protocol.

INTRODUCTION: Suicide has a complex aetiology and is a result of the interaction among the risk and protective factors at the individual, healthcare system and population levels. Therefore, policy and decision makers and mental health service planners can play an important role in suicide prevention. Although a number of suicide risk predictive tools have been developed, these tools were designed to be used by clinicians for assessing individual risk of suicide. There have been no risk predictive models to be used by policy and decision makers for predicting population risk of suicide at the national, provincial and regional levels. This paper aimed to describe the rationale and methodology for developing risk predictive models for population risk of suicide. METHODS AND ANALYSIS: A case-control study design will be used to develop sex-specific risk predictive models for population risk of suicide, using statistical regression and machine learning techniques. Routinely collected health administrative data in Quebec, Canada, and community-level social deprivation and marginalisation data will be used. The developed models will be transformed into the models that can be readily used by policy and decision makers. Two rounds of qualitative interviews with end-users and other stakeholders were proposed to understand their views about the developed models and potential systematic, social and ethical issues for implementation; the first round of qualitative interviews has been completed. We included 9440 suicide cases (7234 males and 2206 females) and 661 780 controls for model development. Three hundred and forty-seven variables at individual, healthcare system and community levels have been identified and will be included in least absolute shrinkage and selection operator regression for feature selection. ETHICS AND DISSEMINATION: This study is approved by the Health Research Ethnics Committee of Dalhousie University, Canada. This study takes an integrated knowledge translation approach, involving knowledge users from the beginning of the process.

The 5-year longitudinal diagnostic profile and health services utilization of patients treated with electroconvulsive therapy in Quebec: a population-based study.

PURPOSE: Electroconvulsive therapy (ECT) is effective for treating several psychiatric disorders. However, only a minority of patients are treated with ECT. It is of primary importance to characterize their profile for epidemiological purposes and to inform clinical practice. We aimed to characterize the longitudinal profile of psychopathology and services utilization of patients first treated with ECT. METHODS: We conducted a population-based comparative study using data from a national administrative database in Quebec. Patients who received a first ECT between 2002 and 2016 were compared to controls who were hospitalized in psychiatry but did not receive ECT. We performed descriptive analyses to compare psychiatric diagnoses, domains of psychopathology (internalizing, externalizing and thought/psychotic disorders), medical services and medication use in the 5 years prior to the ECT or hospitalization. RESULTS: 5 080 ECT patients were compared with 179 594 controls. Depressive, anxiety, bipolar and psychotic disorders were more frequent in the ECT group. 96.2% of ECT patients had been diagnosed with depression and 53.8% with a primary psychotic disorder. In the ECT group, 1.0% had been diagnosed exclusively with depression and 47.0% had disorders from that belong to all three domains of psychopathology. Having both internalizing and thought/psychotic disorders was associated with an increased likelihood of receiving ECT vs having internalizing disorders alone (unadjusted OR = 2.93; 95% CI = 2.63, 3.26). All indicators of mental health services utilization showed higher use among ECT patients. CONCLUSION: Our results provide robust evidence of complex longitudinal psychopathology and extensive services utilization among ECT patients.

Exploring the impact of Quebec's vaccine lottery and vaccine passports on Covid-19 vaccination intention: Findings from repeated cross-sectional surveys.

In Quebec, during the summer of 2021, different strategies to enhance COVID-19 vaccine uptake were implemented (e.g. mobile vaccination clinics, mass communication campaigns, home vaccination). The aim was that at least 75% of 12 years and older individuals receive two doses of COVID-19 vaccines before the fall. This article explores the impact of incentives and disincentive strategies on Quebecers' intention to be vaccinated against COVID-19. A series of cross-sectional surveys have been ongoing in Quebec since March 2020 to measure Quebecers' attitudes and behaviors during the pandemic. In July and August 2021, in addition to sociodemographic information, the survey assessed COVID-19 risks perceptions, adherence to and perception of recommended measures (e.g. masks, physical distancing, vaccine lottery, vaccine passport) as attitudes and intention toward COVID-19 vaccines. Descriptive statistics were generated. Between July 9 to September 1, the vaccine uptake (two doses) rose from 62% to 88%. Among respondents who were unvaccinated during the period, 32% reported a positive influence of the lottery on their intention to be vaccinated against COVID-19 and 39% for the vaccine passport. Approximately half (51%) of unvaccinated respondents reported no influence from the two measures, and both positively influenced 20%. The vaccine lottery had a limited impact on willingness to receive COVID-19 vaccines among unvaccinated adults in Quebec, but the implementation of the vaccine passport appears more influential based on survey respondents' responses.

Measuring Substance-Related Disorders Using Canadian Administrative Health Databanks: Interprovincial Comparisons of Recorded Diagnostic Rates, Incidence Proportions and Mortality Rate Ratios.

CONTEXT: Assessing temporal changes in the recorded diagnostic rates, incidence proportions, and health outcomes of substance-related disorders (SRD) can inform public health policymakers in reducing harms associated with alcohol and other drugs. OBJECTIVE: To report the annual and cumulative recorded diagnostic rates and incidence proportions of SRD, as well as mortality rate ratios (MRRs) by cause of death among this group in Canada, according to their province of residence. METHODS: Analyses were performed on linked administrative health databases (AHD; physician claims, hospitalizations, and vital statistics) in five Canadian provinces (Alberta, Manitoba, Ontario, Québec, and Nova Scotia). Canadians 12 years and older and registered for their provincial healthcare coverage were included. The International Classification of Diseases (ICD-9 or ICD-10 codes) was used for case identification of SRD from April 2001 to March 2018. RESULTS: During the study period, the annual recorded SRD diagnostic rates increased in Alberta (2001-2002: 8.0‰; 2017-2018: 12.8‰), Ontario (2001-2002: 11.5‰; 2017-2018: 14.4‰), and Nova Scotia (2001-2002: 6.4‰; 2017-2018: 12.7‰), but remained stable in Manitoba (2001-2002: 5.5‰; 2017-2018: 5.4‰) and Québec (2001-2002 and 2017-2018: 7.5‰). Cumulative recorded SRD diagnostic rates increased steadily for all provinces. Recorded incidence proportions increased significantly in Alberta (2001-2002: 4.5‰; 2017-2018: 5.0‰) and Nova Scotia (2001-2002: 3.3‰; 2017-2018: 3.8‰), but significantly decreased in Ontario (2001-2002: 6.2‰; 2017-2018: 4.7‰), Québec (2001-2002: 4.1‰; 2017-2018: 3.2‰) and Manitoba (2001-2002: 2.7‰; 2017-2018: 2.0‰). For almost all causes of death, a higher MRR was found among individuals with recorded SRD than in the general population. The causes of death in 2015-2016 with the highest MRR for SRD individuals were SRD, suicide, and non-suicide trauma in Alberta, Ontario, Manitoba, and Québec. DISCUSSION: Linked AHD covering almost the entire population can be useful to monitor the medical service trends of SRD and, therefore, guide health services planning in Canadian provinces.

Morbidities and mortality of diagnosed attention deficit hyperactivity disorder (ADHD) over the youth lifespan: A population-based retrospective cohort study.

OBJECTIVES: To estimate the prevalence of ADHD, and related comorbidities, mortality, and type of health service use among children and young adults, using different case definitions. METHODS: We conducted a population-based retrospective cohort study between 2000 and 2018, using the Quebec Integrated Chronic Disease Surveillance System (QICDSS) database. All residents aged less than 25 years eligible for health insurance coverage were included. We compared outcomes of three indicators (morbidity, services use and mortality) according two different algorithms of ADHD definitions, to the general population. RESULTS: The cumulative prevalence of ADHD has risen steadily over the past decade, reaching 12.6% in 2017-2018. People with ADHD have a higher prevalence of psychiatric comorbidities, make greater use of medical, mental health services, and are hospitalized more often. The comparison of prevalence between the two algorithms and the general population for the three indicators showed that the cohort having one claim was very close to that with two or more, and statistically significant higher to that of people without ADHD. CONCLUSION: This finding support that a single claim algorithm for ADHD can be used for case definition. More research is needed on the impact of potentially effective treatments in improving consequences of ADHD.

Avoidable Hospitalizations in Persons with Dementia: a Population-Wide Descriptive Study (2000-2015).

BACKGROUND: Whether avoidable hospitalizations in community-dwelling persons with dementia have decreased during primary care reforms is unknown. METHODS: We described the prevalence and trends in avoidable hospitalizations in population-based repeated yearly cohorts of 192,144 community-dwelling persons with incident dementia (Quebec, 2000-2015) in the context of a province-wide primary care reform, using the provincial health administrative database. RESULTS: Trends in both types of Ambulatory Care Sensitive Condition (ACSC) hospitalization (general and older population) and 30-day readmission rates remained constant with average rates per 100 person-years: 20.5 (19.9-21.1), 31.7 (31.0-32.4), 20.6 (20.1-21.2), respectively. Rates of delayed hospital discharge (i.e., alternate level of care (ALC) hospitalizations) decreased from 23.8 (21.1-26.9) to 17.9 (16.1-20.1) (relative change -24.6%). CONCLUSIONS: These figures shed light on the importance of the phenomenon, its lack of improvement for most outcomes over the years, and the need to develop evidence-based policies to prevent avoidable hospitalizations in this vulnerable population.

Population coverage of the Canadian Chronic Disease Surveillance System: a survey of the contents of health insurance registries across Canada. / Couverture de la population dans le Système canadien de surveillance des maladies chroniques : enquête sur le contenu des registres d'assurance-maladie au Canada.

INTRODUCTION: Health insurance registries, which capture insurance coverage and demographic information for entire populations, are a critical component of population health surveillance and research when using administrative data. Lack of standardization of registry information across Canada's provinces and territories could affect the comparability of surveillance measures. We assessed the contents of health insurance registries across Canada to describe the populations covered and document registry similarities and differences. METHODS: A survey about the data and population identifiers in health insurance registries was developed by the study team and representatives from the Public Health Agency of Canada. The survey was completed by key informants from most provinces and territories and then descriptively analyzed. RESULTS: Responses were received from all provinces; partial responses were received from the Northwest Territories. Demographic information in health insurance registries, such as primary address, date of birth and sex, were captured in all jurisdictions. Data captured on familial relationships, ethnicity and socioeconomic status varied among jurisdictions, as did start and end dates of coverage and frequency of registry updates. Identifiers for specific populations, such as First Nations individuals, were captured in some, but not all jurisdictions. CONCLUSION: Health insurance registries are a rich source of information about the insured populations of the provinces and territories. However, data heterogeneity may affect who is included and excluded in population surveillance estimates produced using administrative health data. Development of a harmonized data framework could support timely and comparable population health research and surveillance results from multi-jurisdiction studies.

Utilization of Health Care Services by Patients With Cluster B Personality Disorders or Schizophrenia.

OBJECTIVE: The comparable severities of cluster B personality disorders and schizophrenia are increasingly recognized. The authors sought to compare the general medical and psychiatric comorbid conditions and use of medical services among individuals with one or both of these disorders. METHODS: Data were collected from the linked health administrative databases of Quebec's universal health plan in the Quebec Integrated Chronic Disease Surveillance System, which covers 99% of Quebec's population. The study cohort of 2016-2017 included almost 7.05 million people, and the study covered the 1996-2017 period. RESULTS: Comorbid conditions were extremely prevalent in the three groups studied-persons with cluster B personality disorders, schizophrenia, or both-compared with the general population. People having both disorders had the highest prevalence of comorbid conditions. Psychiatric services were used more frequently by individuals in all three groups than among those in the general population, and use was especially high among people with both disorders. Medical care service use was heterogeneous, with patients with cluster B personality disorders using more medical care services but fewer specialized outpatient treatments and psychotherapy than those with schizophrenia or with both disorders. CONCLUSIONS: The three cohorts had higher rates of comorbid conditions and health care service use than individuals in the general population. Patients with cluster B personality disorders used fewer psychiatric services than patients with schizophrenia or with both disorders. One explanation for this difference may be that people with cluster B personality disorders encounter more obstacles in accessing mental health care services.

Primary care continuity and potentially avoidable hospitalization in persons with dementia.

BACKGROUND/OBJECTIVE: To measure the association between high primary care continuity and potentially avoidable hospitalization in community-dwelling persons with dementia. Our hypothesis was that high primary care continuity is associated with fewer potentially avoidable hospitalizations. DESIGN: Population-based retrospective cohort (2012-2016), with inverse probability of treatment weighting using the propensity score. SETTING: Quebec (Canada) health administrative database, recording most primary, secondary and tertiary care services provided via the public universal health insurance system. PARTICIPANTS: Population-based sample of 22,060 community-dwelling 65 + persons with dementia on March 31st, 2015, with at least two primary care visits in the preceding year (mean age 81 years, 60% female). Participants were followed for 1 year, or until death or long-term care admission. EXPOSURE: High primary care continuity on March 31st, 2015, i.e., having had every primary care visit with the same primary care physician, during the preceding year. MAIN OUTCOME MEASURES: Primary: Potentially avoidable hospitalization in the follow-up period as defined by ambulatory care sensitive conditions (ACSC) hospitalization (general and older population definitions), 30-day hospital readmission; Secondary: Hospitalization and emergency department visit. RESULTS: Among the 22,060 persons, compared with the persons with low primary care continuity, the 14,515 (65.8%) persons with high primary care continuity had a lower risk of ACSC hospitalization (general population definition) (relative risk reduction 0.82, 95% CI 0.72-0.94), ACSC hospitalization (older population definition) (0.87, 0.79-0.95), 30-day hospital readmission (0.81, 0.72-0.92), hospitalization (0.90, 0.86-0.94), and emergency department visit (0.92, 0.90-0.95). The number needed to treat to prevent one event were, respectively, 118 (69-356), 87 (52-252), 97 (60-247), 23 (17-34), and 29 (21-47). CONCLUSION: Increasing continuity with a primary care physician might be an avenue to reduce potentially avoidable hospitalizations in community-dwelling persons with dementia on a population-wide level.