Comparison of mortality hazard ratios associated with health behaviours in Canada and the United States: a population-based linked health survey study.

BACKGROUND: Modern health surveillance and planning requires an understanding of how preventable risk factors impact population health, and how these effects vary between populations. In this study, we compare how smoking, alcohol consumption, diet and physical activity are associated with all-cause mortality in Canada and the United States using comparable individual-level, linked population health survey data and identical model specifications. METHODS: The Canadian Community Health Survey (CCHS) (2003-2007) and the United States National Health Interview Survey (NHIS) (2000, 2005) linked to individual-level mortality outcomes with follow up to December 31, 2011 were used. Consistent variable definitions were used to estimate country-specific mortality hazard ratios with sex-specific Cox proportional hazard models, including smoking, alcohol, diet and physical activity, sociodemographic indicators and proximal factors including disease history. RESULTS: A total of 296,407 respondents and 1,813,884 million person-years of follow-up from the CCHS and 58,232 respondents and 497,909 person-years from the NHIS were included. Absolute mortality risk among those with a 'healthy profile' was higher in the United States compared to Canada, especially among women. Adjusted mortality hazard ratios associated with health behaviours were generally of similar magnitude and direction but often stronger in Canada. CONCLUSION: Even when methodological and population differences are minimal, the association of health behaviours and mortality can vary across populations. It is therefore important to be cautious of between-study variation when aggregating relative effect estimates from differing populations, and when using external effect estimates for population health research and policy development.

Self-reported eye health in Canada: 20 years of data.

Context: Eye health is an indicator of health in general. Few studies on eye health have been done in Canada, and none of them covered several years of data. Data and Methods: Data from the Canadian Community Health Survey for most years from 2000 to 2020 were used. Eye health was analyzed, by year, sex and age, as well as by immigrant status, the highest level of education in the household and the income quintile of the household. Estimates were obtained using survey weights, and 95% confidence intervals were obtained with bootstrap weights. Results: In 2020, the proportion of the population that reported having good vision without correction was about 75% among youth aged 12 to 19 years for both sexes. This proportion was considerably lower for those aged around 45 to 49 years and was about 25% for those aged 55 years or older. Self-reported good vision without correction improved from 2000/2001 to 2020, except for those aged 20 to 39 years old. Every year, fewer females than males reported having good vision without correction. Interpretation: Self-reported eye health generally improved during the period of this study. Limitations of the survey arise from the fact that it uses self-reported data. Moreover, the survey underwent important changes in 2015 that could limit the comparability of data during the period of the study. However, the large number of years included in the study and the stability of the results validate the conclusions.

Sociodemographic and endogenous factors associated with access to eye care in Canada, 2016 to 2019.

Introduction: Eye care is important, but it is not always promoted as much as other aspects of health. A visit to an eye care professional is made when need, stimulus, access and availability exist. Data and methods: Data from cycles 5 and 6 (2016 to 2019) of the Canadian Health Measures Survey were used. Analyzed variables were related to sociodemographic characteristics, general health, behaviour and eye health. Estimates were obtained using survey weights, and 95% confidence intervals were obtained with bootstrap weights. Results: From 2016 to 2019, 75% of people diagnosed with diabetes visited an eye care professional during the previous year. For people not diagnosed with diabetes, the rate varied, at 57% for those aged 6 to 18 years, 40% for those aged 19 to 64, and 63% for those aged 65 to 79. For those aged 6 to 64, wearing glasses and having access to a family doctor were the main factors associated with a visit to an eye care professional in the previous year. For those aged 65 to 79, cataracts, sex, marital status and self-perceived quality of life were the most significant factors. Interpretation: Although wearing glasses or having eye diseases was associated with a visit to an eye care professional, this study revealed additional emerging associated factors: access to a family doctor for people aged 6 to 64, and an excellent or very good self-perceived quality of life for those aged 65 to 79.

Measuring health related quality of life (HRQoL) in community and facility-based care settings with the interRAI assessment instruments: development of a crosswalk to HUI3.

BACKGROUND: Health-related quality of life (HRQoL) measures are of interest because they can be used to describe health of populations and represent a broader health outcome for population health analyses than mortality rates or life expectancy. The most widely used measure of HRQoL for deriving estimates of health-adjusted life expectancy is the Health Utilities Index Mark 3 (HUI3). The HUI3 is available in most national surveys administered by Statistics Canada, and has been used as part of a microsimulation model to examine the impact of neurological conditions over the life course. Persons receiving home care and nursing home services are often not well-represented in these surveys; however, interRAI assessment instruments are now used as part of normal clinical practice in these settings for nine Canadian provinces/territories. Building on previous research that developed a HUI2 crosswalk for the interRAI assessments, the present study examined a new interRAI HRQoL index crosswalked to the HUI3. METHODS: interRAI and survey data were used to examine the distributional properties of global and domain-specific interRAI HRQoL and HUI3 index scores, respectively. Three populations were considered: well-elderly persons not receiving home care, home care clients and nursing home residents. RESULTS: The mean HUI3 and interRAI HRQoL index global scores declined from independent healthy older persons to home care clients, followed by nursing home residents. For the home care and nursing home populations, the interRAI HRQoL global estimates tended to be lower than HUI3 global scores obtained from survey respondents. While there were some statistically significant age, sex and diagnostic group differences in global scores and within attributes, the most notable differences were between populations from different care settings. DISCUSSION: The present study provides strong evidence for the validity of the interRAI HRQoL based on comparisons of distributional properties with those obtained with survey data based on the HUI3. The results demonstrate the importance of admission criteria for home care and nursing home settings, where function plays a more important role than demographic or diagnostic criteria. The interRAI HRQoL has a distinct advantage because it is gathered as part of normal clinical practice in care settings where interRAI instruments are mandatory and are used to assess all eligible persons in those sectors. In particular, those with severe cognitive and functional impairments (who tend to be under-represented in survey data) will be evaluated using the interRAI tools. Future research should build on this work by providing direct, person-level comparisons of interRAI HRQoL index and HUI3 scores, as well as longitudinal analyses to examine responsiveness to change.

Associations between fine particulate matter and mortality in the 2001 Canadian Census Health and Environment Cohort.

BACKGROUND: Large cohort studies have been used to characterise the association between long-term exposure to fine particulate matter (PM2.5) air pollution with non-accidental, and cause-specific mortality. However, there has been no consensus as to the shape of the association between concentration and response. METHODS: To examine the shape of this association, we developed a new cohort based on respondents to the 2001 Canadian census long-form. We applied new annual PM2.5 concentration estimates based on remote sensing and ground measurements for Canada at a 1km spatial scale from 1998 to 2011. We followed 2.4 million respondents who were non-immigrants aged 25-90 years and did not reside in an institution over a 10 year period for mortality. Exposures were assigned as a 3-year mean prior to the follow-up year. Income tax files were used to account for residential mobility among respondents using postal codes, with probabilistic imputation used for missing postal codes in the tax data. We used Cox survival models to determine hazard ratios (HRs) for cause-specific mortality. We also estimated Shape Constrained Health Impact Functions (a concentration-response function) for selected causes of death. RESULTS: In models stratified by age, sex, airshed, and population centre size, and adjusted for individual and neighbourhood socioeconomic variables, HR estimates for non-accidental mortality were HR = 1.18 (95% CI: 1.15-1.21) per 10µg/m3 increase in concentration. We observed higher HRs for cardiovascular disease (HR=1.25; 95% CI: 1.19-1.31), cardio-metabolic disease (HR = 1.27; 95% CI: 1.21-1.33), ischemic heart disease (HR = 1.36; 95% CI: 1.28-1.44) and chronic obstructive pulmonary disease (COPD) mortality (HR = 1.24; 95% CI: 1.11-1.39) compared to HR for all non-accidental causes of death. For non-accidental, cardio-metabolic, ischemic heart disease, respiratory and COPD mortality, the shape of the concentration-response curve was supra-linear, with larger differences in relative risk for lower concentrations. For both pneumonia and lung cancer, there was some suggestion that the curves were sub-linear. CONCLUSIONS: Associations between ambient concentrations of fine particulate matter and several causes of death were non-linear for each cause of death examined.

Alzheimer's and other dementias in Canada, 2011 to 2031: a microsimulation Population Health Modeling (POHEM) study of projected prevalence, health burden, health services, and caregiving use.

BACKGROUND: Worldwide, there is concern that increases in the prevalence of dementia will result in large demands for caregivers and supportive services that will be challenging to address. Previous dementia projections have either been simple extrapolations of prevalence or macrosimulations based on dementia incidence. METHODS: A population-based microsimulation model of Alzheimer's and related dementias (POHEM:Neurological) was created using Canadian demographic data, estimates of dementia incidence, health status (health-related quality of life and mortality risk), health care costs and informal caregiving use. Dementia prevalence and 12 other measures were projected to 2031. RESULTS: Between 2011 and 2031, there was a projected two-fold increase in the number of people living with dementia in Canada (1.6-fold increase in prevalence rate). By 2031, the projected informal (unpaid) caregiving for dementia in Canada was two billion hours per year, or 100 h per year per Canadian of working age. CONCLUSIONS: The projected increase in dementia prevalence was largely related to the expected increase in older Canadians, with projections sensitive to changes in the age of dementia onset.

Development and implementation of microsimulation models of neurological conditions.

BACKGROUND: As part of a program of the first National Population Health Study of Neurological Conditions launched in 2009, a series of microsimulation models of neurological conditions (called POHEM-Neurological meta-model) was developed to project health and economic impacts of seven neurological conditions (NCs)-Alzheimer's disease and other dementias, cerebral palsy, epilepsy, multiple sclerosis, Parkinson's disease, traumatic brain injury, and traumatic spinal cord injury-over a 20-year horizon. DATA AND METHODS: The common framework of the seven models allows for dynamic, continuous-time, discrete-event simulation of synthetic large populations in which persons are subject to the risk of developing the NC under study and are assigned a value of functional health and a probability of receiving a caregiver and of entering long-term care. Calculations for transitions are done every year over the life course, and costs are accumulated throughout the life of the synthetic person. The need to reconcile empirical estimates of incidence and mortality with prevalence required implementation of "cure" parameters for two of the NCs. RESULTS: The POHEM-Neurological meta-model integrates the latest Canadian microdata on neurological conditions and satisfies most criteria for validation of microsimulation models, including conceptualization, computer implementation, assessment of output plausibility, and comparison with external data. Limitations include an absence of risk factors and the lack of uncertainty measures. INTERPRETATION: The POHEM-Neurological meta-model has been useful for projections of health and economic impacts of NCs on persons affected and their caregivers, and allows for comparison of specific scenarios to the base case.

Linking the Canadian Community Health Survey and the Canadian Mortality Database: An enhanced data source for the study of mortality.

BACKGROUND: This study summarizes the linkage of the Canadian Community Health Survey (CCHS) and the Canadian Mortality Database (CMDB), which was performed to examine relationships between social determinants, health behaviours and mortality in the household population. DATA AND METHODS: The 2000/2001-to-2011 Canadian Community Health Surveys were linked to the 2000-to-2011 CMDB using probabilistic methods based on common identifiers (names, date of birth, postal code and sex) for eligible respondents (85%; n = 614,774). Mortality records from January 1, 2000 through December 31, 2011 for people aged 12 or older were eligible for linkage (n = 2.774 million). The linkage was enhanced with information from the Historical Tax Summary File. Quality assessment consisted of internal and external validation. Cox survival analysis (age-adjusted) was conducted to estimate hazard ratios (HRs) associated with selected health behaviours. RESULTS: Overall, 5.3% of eligible CCHS respondents linked to a mortality record; false positive and false negative rates were 0.04% and 2.43%, respectively. Linkage rates were higher among males (5.8%) and people aged 75 or older (20.2%), reflecting known mortality risks. Survival analyses confirmed elevated mortality risk associated with heavy (HR 2.36, CI 1.84, 2.89) and light smoking (HR 1.91, CI 1.52, 2.33), compared with not smoking; underweight and obesity, compared with normal and overweight; low fruit and vegetable consumption; and lack of physical activity. INTERPRETATION: Linking health behaviour information from the CCHS to mortality data from the CMDB allows for a greater understanding of modifiable determinants of mortality.

Unintentional injury hospitalizations and socio-economic status in areas with a high percentage of First Nations identity residents.

BACKGROUND: Few national studies of hospitalizations due to injuries among the First Nations population have been conducted. DATA AND METHODS: Based on 2004/2005 to 2009/2010 data from the Discharge Abstract Database, this study examines associations between unintentional injury hospitalizations, socio-economic status and location relative to an urban core in Dissemination Areas (DAs) with a high percentage of First Nations identity residents versus a low percentage of Aboriginal identity residents. RESULTS: Unintentional injury hospitalization rates were higher in the less affluent and the most remote DAs. When DAs with the same socio-economic status and location were compared, the risk of hospitalizations was greater in high-percentage First Nations identity DAs relative to low-percentage Aboriginal identity DAs. INTERPRETATION: Socio-economic conditions and remote location accounted for some, but not all, of the differences in unintentional injury hospitalizations between high-percentage First Nations identity and low-percentage Aboriginal identity DAs. This suggests that characteristics not measured in this analysis--such as environmental, behavioural or other factors--play an additional role in DA-level unintentional injury hospitalization risk.

Canadian Cancer Risk Management Model: evaluation of cancer control.

OBJECTIVES: The aim of this study was to develop a decision support tool to assess the potential benefits and costs of new healthcare interventions. METHODS: The Canadian Partnership Against Cancer (CPAC) commissioned the development of a Cancer Risk Management Model (CRMM)--a computer microsimulation model that simulates individual lives one at a time, from birth to death, taking account of Canadian demographic and labor force characteristics, risk factor exposures, and health histories. Information from all the simulated lives is combined to produce aggregate measures of health outcomes for the population or for particular subpopulations. RESULTS: The CRMM can project the population health and economic impacts of cancer control programs in Canada and the impacts of major risk factors, cancer prevention, and screening programs and new cancer treatments on population health and costs to the healthcare system. It estimates both the direct costs of medical care, as well as lost earnings and impacts on tax revenues. The lung and colorectal modules are available through the CPAC Web site (www.cancerview.ca/cancerrriskmanagement) to registered users where structured scenarios can be explored for their projected impacts. Advanced users will be able to specify new scenarios or change existing modules by varying input parameters or by accessing open source code. Model development is now being extended to cervical and breast cancers.

Modelling risk factor information for linked census data: The case of smoking.

BACKGROUND: Statistics Canada has initiated a series of data linkages of Census of Population long form and health outcome data. These linked data lack risk factor information. This study assesses the feasibility of using statistical modelling techniques to assign smoking status to census respondents. DATA AND METHODS: The 2000/2001 Canadian Community Health Survey (CCHS) was used to develop age-/sex-specific predictive models to model smoking status based on variables available on the 1991 Census. The 2002/2003 CCHS was used to validate the modelled variable. Data from the 2002/2003 CCHS linked to data from the Hospital Morbidity Database (2001/2002 to 2004/2005) were used to evaluate the use of modelled versus self-reported smoking status on smoking-related hospitalizations. RESULTS: For the current daily smoker models, income, education, marital status, dwelling ownership and region of birth were significant predictors. For the never smoker models, marital status, dwelling ownership, Aboriginal identity and region of birth were significant predictors. Modelled current daily smoker status was associated with increased odds of smoking-related hospitalization, compared with being a never smoker, even when adjusting for covariates. INTERPRETATION: This study demonstrates the feasibility of using statistical modelling techniques to assign smoking status to census data, provided socio-economic and identity information is available.

Validation of population-based disease simulation models: a review of concepts and methods.

BACKGROUND: Computer simulation models are used increasingly to support public health research and policy, but questions about their quality persist. The purpose of this article is to review the principles and methods for validation of population-based disease simulation models. METHODS: We developed a comprehensive framework for validating population-based chronic disease simulation models and used this framework in a review of published model validation guidelines. Based on the review, we formulated a set of recommendations for gathering evidence of model credibility. RESULTS: Evidence of model credibility derives from examining: 1) the process of model development, 2) the performance of a model, and 3) the quality of decisions based on the model. Many important issues in model validation are insufficiently addressed by current guidelines. These issues include a detailed evaluation of different data sources, graphical representation of models, computer programming, model calibration, between-model comparisons, sensitivity analysis, and predictive validity. The role of external data in model validation depends on the purpose of the model (e.g., decision analysis versus prediction). More research is needed on the methods of comparing the quality of decisions based on different models. CONCLUSION: As the role of simulation modeling in population health is increasing and models are becoming more complex, there is a need for further improvements in model validation methodology and common standards for evaluating model credibility.

Cerebral palsy in Canada, 2011-2031: results of a microsimulation modelling study of epidemiological and cost impacts. / La paralysie cérébrale au Canada, 2011-2031 : résultats d'une étude de modélisation par microsimulation des répercussions épidémiologiques et économiques.

INTRODUCTION: The objective of our study was to present model-based estimates and projections on current and future health and economic impacts of cerebral palsy in Canada over a 20-year time horizon (2011-2031). METHODS: We used Statistics Canada's Population Health Model (POHEM)-Neurological to simulate individuals' disease states, risk factors and health determinants and to describe and project health outcomes, including disease incidence, prevalence, life expectancy, health-adjusted life expectancy, health-related quality of life and health care costs over the life cycle of Canadians. Cerebral palsy cases were identified from British Columbia's health administrative data sources. A population-based cohort was then used to generate the incidence and mortality rates, enabling the projection of future incidence and mortality rates. A utility-based measure (Health Utilities Index Mark 3) was also included in the model to reflect various states of functional health to allow projections of health-related quality of life. Finally, we estimated caregiving parameters and health care costs from Canadian national surveys and health administrative data and included them as model parameters to assess the health and economic impact of cerebral palsy. RESULTS: Although the overall crude incidence rate of cerebral palsy is projected to remain stable, newly diagnosed cases of cerebral palsy will rise from approximately 1800 in 2011 to nearly 2200 in 2031. In addition, the number of people with the condition is expected to increase from more than 75 000 in 2011 to more than 94 000 in 2031. Direct health care costs in constant 2010 Canadian dollars were about $11 700 for children with cerebral palsy aged 1-4 years versus about $600 for those without the condition. In addition, people with cerebral palsy tend to have longer periods in poorer health-related quality of life. CONCLUSION: Individuals with cerebral palsy will continue to face challenges related to an ongoing need for specialized medical care and a rising need for supportive services. Our study offers important insights into future costs and impacts associated with cerebral palsy and provides valuable information that could be used to develop targeted health programs and strategies for Canadians living with this condition.

Multiple sclerosis in Canada 2011 to 2031: results of a microsimulation modelling study of epidemiological and economic impacts. / La sclérose en plaques au Canada, 2011-2031 : résultats d'une étude de modélisation par microsimulation des répercussions épidémiologiques et économiques.

INTRODUCTION: The objective of our study was to present model-based estimates and projections on current and future health and economic impacts of multiple sclerosis (MS) in Canada over a 20-year time horizon (2011-2031). METHODS: Using Statistics Canada's Population Health Microsimulation Model (POHEM) framework, specifically the population-based longitudinal, microsimulation model named POHEM-Neurological, we identified people with MS from health administrative data sources and derived incidence and mortality rate parameters from a British Columbia population-based cohort for future MS incidence and mortality projections. We also included a utility-based measure (Health Utilities Index Mark 3) reflecting states of functional health to allow projections of health-related quality of life. Finally, we estimated caregiving parameters and health care costs from Canadian national surveys and health administrative data and included them as model parameters to assess the health and economic impact of the neurological conditions. RESULTS: The number of incident MS cases is expected to rise slightly from 4051 cases in 2011 to 4794 cases per 100 000 population in 2031, and the number of Canadians affected by MS will increase from 98 385 in 2011 to 133 635 in 2031. The total per capita health care cost (excluding out-of-pocket expenses) for adults aged 20 and older in 2011 was about $16 800 for individuals with MS, and approximately $2500 for individuals without a neurological condition. Thus, after accounting for additional expenditures due to MS (excluding out-of-pocket expenses), total annual health sector costs for MS are expected to reach $2.0 billion by 2031. As well, the average out-of-pocket expenditure for people with MS was around $1300 annually throughout the projection period. CONCLUSION: MS is associated with a significant economic burden on society, since it usually affects young adults during prime career- and family-building years. Canada has a particularly high prevalence of MS, so research such as the present study is essential to provide a better understanding of the current and future negative impacts of MS on the Canadian population, so that health care system policymakers can best plan how to meet the needs of patients who are affected by MS. These findings also suggest that identifying strategies to prevent MS and more effectively treat the disease are needed to mitigate these future impacts.

INTRODUCTION: L'objectif de notre étude est de présenter des estimations et des projections des répercussions épidémiologiques et économiques de la sclérose en plaques (SP) au Canada sur 20 ans (2011-2031). MÉTHODOLOGIE: Nous avons utilisé un modèle de microsimulation de la santé de la population (POHEM) de Statistique Canada, plus précisément le modèle longitudinal de microsimulation démographique appelé POHEM - Maladies neurologiques. Nous avons sélectionné les personnes atteintes de SP à partir de sources de données administratives sur la santé et dérivé les paramètres liés à l'incidence de la maladie et au taux de décès d'une étude de cohorte de la Colombie-Britannique afin de prévoir quels seront l'incidence de la SP et son taux de décès. Nous avons également inclus une mesure reposant sur l'utilité (Health Utilities Index Mark 3) qui rend compte des états de santé fonctionnelle afin de réaliser des projections sur la qualité de vie liée à la santé. Enfin, nous avons estimé les paramètres de prestation de soins et de coûts des soins de santé à partir de sondages nationaux du Canada et de données administratives sur la santé et nous les avons inclus comme paramètres dans le modèle visant à évaluer les répercussions économiques et sur la santé des maladies neurologiques. RÉSULTATS: On anticipe une légère augmentation du nombre de cas incidents de SP, passant de 4 051 cas pour 100 000 personnes en 2011 à 4 974 en 2031. Le nombre de Canadiens touchés par la SP passera ainsi de 98 385 en 2001 à 133 635 en 2031. Le coût total des soins de santé par personne (à l'exception des dépenses directes) pour les adultes de 20 ans et plus atteints de SP en 2011 était d'environ 16 800 $, contre un peu moins de 2500 $ pour ceux ne souffrant d'aucune affection neurologique. Si on comptabilise les dépenses supplémentaires liées à la SP (à l'exception des dépenses directes), les coûts totaux annuels de la SP pour le secteur de la santé devraient donc atteindre deux milliards de dollars d'ici 2031. Par ailleurs, les dépenses directes moyennes des personnes atteintes de SP seront d'environ 1300 $ par année tout au long de la période de projection. CONCLUSION: La SP est associée à un important fardeau économique pour la société car elle touche surtout de jeunes adultes à un moment fondateur pour leur vie professionnelle et leur vie familiale. Sa prévalence étant particulièrement élevée au Canada, des recherches comme la nôtre sont essentielles afin de mieux comprendre les répercussions actuelles et futures de la SP sur la population canadienne, afin que les décideurs du réseau de la santé puissent mieux planifier les besoins en soins de santé pour les malades qui en sont atteints. Selon ces résultats, des stratégies pour prévenir la SP et la traiter plus efficacement sont essentielles pour en atténuer les futures répercussions.

Prevalence and characteristics of body piercing and tattooing among high school students.

BACKGROUND: Although body piercing and tattooing seem to be gaining popularity among a diversity of social and age groups, studies of these practices in general adolescent populations are scarce. This study establishes the prevalence of body modification (tattooing and body piercing) among high school students in grades 7-11 (aged 12 to 18). METHODS: Data come from a 2002 in-school survey conducted among a representative sample of 2,180 students (81% response rate) enrolled in the 23 high schools of the Outaouais region in Quebec. Systematic sampling was performed. Specific data on tattooing and body piercing are available for 2,145 students (1% non-response rate). RESULTS: A prevalence of 27% for body piercing and 8% for tattooing is observed among high school students. Differences between girls and boys are observed in many ways: i.e., frequency and number of tattoos or piercings; aftercare practices. While most teens say that a "professional" in a studio performed their body modification and that they received aftercare instruction, a high percentage of students report health complications following the procedure. CONCLUSION: Results show that tattooing and body piercing are common among adolescents and may involve health risks. Consequently, appropriate preventive measures should be adopted by professionals such as school counsellors, nurses, physicians and others who are in contact with teenagers to help them make informed choices.

Effects of Reductions in Body Mass Index on the Future Osteoarthritis Burden in Canada: A Population-Based Microsimulation Study.

OBJECTIVE: Osteoarthritis (OA) is the most common joint disease and a major cause of disability. Incidence and prevalence of OA are expected to increase due to population aging and increased levels of obesity. The purpose of this study was to project the effect of hypothetical interventions that change the distribution of body mass index (BMI) on OA burden in Canada. METHODS: We used a microsimulation computer model of OA based on the Population Health Model platform. The model used demographic predictions for Canada and population data from an administrative database in British Columbia and national Canadian surveys. RESULTS: Under the base-case scenario, between 2010 and 2030, OA prevalence is expected to increase from 11.5% to 15.6% in men and 16.3% to 21.1% in women. In scenarios assuming, on average, a 0.3-, 0.5-, or 1-unit drop in BMI per year, OA prevalence in 2030 would reach 14.9%, 14.6%, and 14.2% in men and 20.3%, 19.7%, and 18.5%, in women, respectively. Under these scenarios, the proportion of new cases prevented would be 9.5%, 13.2%, and 16.7%, respectively, in men, and 9.1%, 15.2%, and 25.0% in women. Targeting only those people ages ≥50 years for weight reduction would achieve approximately 70% of the impact of a full population strategy. Targeting only the obese (BMI ≥30) would likely result in a larger benefit for men than women. CONCLUSION: Due to the aging of the population, OA will remain a major and growing health issue in Canada over the next 2 decades, regardless of the course of the obesity epidemic.

Projections of preventable risks for cardiovascular disease in Canada to 2021: a microsimulation modelling approach.

BACKGROUND: Reductions in preventable risks associated with cardiovascular disease have contributed to a steady decrease in its incidence over the past 50 years in most developed countries. However, it is unclear whether this trend will continue. Our objective was to examine future risk by projecting trends in preventable risk factors in Canada to 2021. METHODS: We created a population-based microsimulation model using national data on births, deaths and migration; socioeconomic data; cardiovascular disease risk factors; and algorithms for changes in these risk factors (based on sociodemographic characteristics and previous cardiovascular disease risk). An initial population of 22.5 million people, representing the Canadian adult population in 2001, had 13 characteristics including the risk factors used in clinical risk prediction. There were 6.1 million potential exposure profiles for each person each year. Outcome measures included annual prevalence of risk factors (smoking, obesity, diabetes, hypertension and lipid levels) and of co-occurring risks. RESULTS: From 2003 to 2009, the projected risks of cardiovascular disease based on the microsimulation model closely approximated those based on national surveys. Except for obesity and diabetes, all risk factors were projected to decrease through to 2021. The largest projected decreases were for the prevalence of smoking (from 25.7% in 2001 to 17.7% in 2021) and uncontrolled hypertension (from 16.1% to 10.8%). Between 2015 and 2017, obesity was projected to surpass smoking as the most prevalent risk factor. INTERPRETATION: Risks of cardiovascular disease are projected to decrease modestly in Canada, leading to a likely continuing decline in its incidence.

Data resource profile: 1991 Canadian Census Cohort.

The 1991 Canadian Census Cohort is the largest population-based cohort in Canada (N=2,734,835). Prior to the creation of this Cohort, no national population-based Canadian cohort was available to examine mortality by socioeconomic indicators. The 1991 Canadian Census Cohort was created via the linkage of a sub-sample of respondents from the mandatory 1991 Canadian Census long-form to historical tax summary files, Canadian Mortality Database, Canadian Cancer Database, 1991 Health and Activity Limitation Survey and a sub-sample of the Longitudinal Worker File. Overall ascertainment of mortality and cancer is anticipated to be nearly complete and the Cohort is broadly representative of most groups in the Canadian population. The Cohort has been used to examine mortality outcomes by different indicators of socioeconomic status, occupational categories, ethnic groups, educational attainment, and for exposure to ambient air pollution. Results have shown that the estimated remaining years of life at age 25 differed substantially by income adequacy quintile, educational attainment, housing type and Aboriginal ancestry.

Acute care hospital days and mental diagnoses.

BACKGROUND: Data from the Discharge Abstract Database of the Canadian Institute for Health Information were used to examine acute care hospital days for patients with a mental condition coded as the most responsible diagnosis or a comorbid diagnosis. In 2009/2010, patients with a mental diagnosis represented 11.8% of people who had been hospitalized and 25.5% of acute care hospital days. Those for whom the mental condition was the most responsible diagnosis accounted for 9.0% of hospital days (1.2 million), and those with a comorbid mental diagnosis accounted for 16.5% of hospital days (2.3 million). Mental diagnoses were often associated with physical conditions. The average hospitalization with a mental diagnosis was two and a half times as long as the average for hospitalizations without a mental diagnosis. About one-quarter of hospital days with a mental diagnosis were designated as alternate level of care days.

Thirty-day in-hospital revascularization and mortality rates after acute myocardial infarction in seven Canadian provinces.

BACKGROUND: Recent clinical trials have demonstrated benefit with early revascularization following acute myocardial infarction (AMI). Trends in and the association between early revascularization after (ie, 30 days or fewer) AMI and early death were determined. METHODS AND RESULTS: The Statistics Canada Health Person-Oriented Information Database, consisting of hospital discharge records for seven provinces from the Canadian Institute for Health Information Hospital Morbidity Database, was used. If there was no AMI in the preceding year, the first AMI visit within a fiscal year for a patient 20 years of age or older was included. Times to death in hospital and to revascularization procedures were counted from the admission date of the first AMI visit. Mixed model regression analyses with random slopes were used to assess the relationship between early revascularization and mortality. The overall rate of revascularization within 30 days of AMI increased significantly from 12.5% in 1995 to 37.4% in 2003, while the 30-day mortality rate decreased significantly from 13.5% to 10.6%. There was a linearly decreasing relationship - higher regional use of revascularization was associated with lower mortality in both men and women. CONCLUSIONS: These population-based utilization and outcome findings are consistent with clinical trial evidence of improved 30-day in-hospital mortality with increased early revascularization after AMI.

HISTORIQUE: De récents essais cliniques ont démontré l'avantage d'une revascularisation précoce après l'infarctus aigu du myocarde (IAM). Les tendances quant à la revascularisation précoce (c.-à-d., après 30 jours ou moins) dans l'IAM et son lien avec la mortalité précoce ont été déterminés. RÉSULTATS: Les auteurs ont utilisé la Base de données sur la santé orientée vers la personne de Statistique Canada, composée des dossiers de congés hospitaliers pour sept provinces de la Base de données sur la morbidité de l'Institut canadien d'information sur la santé. En l'absence d'IAM au cours de l'année précédente, les premières visites pour IAM à l'intérieur d'une année fiscale pour les patients de 20 ans ou plus ont été compilées. Le temps avant décès à l'hôpital ou avant revascularisation a été calculé à partir de la date de l'admission lors d'une première visite pour IAM. Les auteurs ont procédé à des analyses de régression selon un modèle mixte avec courbes aléatoires afin d'évaluer le lien entre la revascularisation précoce et la mortalité. Le taux global de revascularisation dans les 30 jours suivant l'IAM a significativement augmenté, de 12,5 % en 1995 à 37,4 % en 2003, tandis que le taux de mortalité à 30 jours a significativement diminué de 13,5 % à 10,6 %. On a noté un lien linéairement décroissant ­ l'utilisation régionale plus élevée de la revascularisation a été associée à une mortalité moindre chez les hommes et chez les femmes. CONCLUSIONS: Ces résultats basés dans la population sur l'utilisation et l'issue de l'intervention concordent avec les conclusions des essais cliniques quant à l'amélioration de la mortalité perhospitalière dans les 30 jours associée à un taux plus élevé de revascularisation précoce après l'IAM.