Analyse de la relation entre le revenu et la mortalité : un commentaire méthodologique

La région urbaine de l’Outaouais (Gatineau) a un revenu moyen plus élevé que le Québec urbain; cependant, ses indicateurs de santé sont moins favorables. Cette situation, contraire à ce que l’on retrouve le plus souvent au niveau de la santé des populations, est désignée par l’expression « paradoxe outaouais ». Nous avons pu analyser l’impact des choix méthodologiques sur l’évaluation de la relation entre le revenu et la santé, au niveau de la ville et au niveau du quintile de revenu. Selon que l’unité de référence est le Québec urbain ou la RMR Ottawa-Gatineau, le paradoxe se réalise ou disparaît. Selon la partition utilisée, le gradient de l’espérance de vie ainsi que l’écart entre Ottawa et Gatineau varient de manière appréciable. Nos résultats montrent que les choix méthodologiques jouent un rôle important et doivent par conséquent être faits avec soin.The Outaouais urban area (Gatineau) has a higher average income compared to the rest of urban Quebec, but its health indicators are less favourable. This situation, contrary to what is usually expected for population health, has been called “the Outaouais paradox”. We have been able to analyse the impact of methodological choices on the evaluation of the relationship between income and health, at the city level and at the income quintile level. If the reference unit is urban Quebec the paradox appears, but if the reference unit is the Ottawa-Gatineau CMA, the paradox disappears. Depending on the partition used, the life expectancy gradient as well as the gap between Ottawa and Gatineau differ substantially. Our results show that methodological choices play an important role and must thus be done cautiously

Uncertainty Analysis in Population-Based Disease Microsimulation Models

Objective. Uncertainty analysis (UA) is an important part of simulation model validation. However, literature is imprecise as to how UA should be performed in the context of population-based microsimulation (PMS) models. In this expository paper, we discuss a practical approach to UA for such models. Methods. By adapting common concepts from published UA guidelines, we developed a comprehensive, step-by-step approach to UA in PMS models, including sample size calculation to reduce the computational time. As an illustration, we performed UA for POHEM-OA, a microsimulation model of osteoarthritis (OA) in Canada. Results. The resulting sample size of the simulated population was 500,000 and the number of Monte Carlo (MC) runs was 785 for 12-hour computational time. The estimated 95% uncertainty intervals for the prevalence of OA in Canada in 2021 were 0.09 to 0.18 for men and 0.15 to 0.23 for women. The uncertainty surrounding the sex-specific prevalence of OA increased over time. Conclusion. The proposed approach to UA considers the challenges specific to PMS models, such as selection of parameters and calculation of MC runs and population size to reduce computational burden. Our example of UA shows that the proposed approach is feasible. Estimation of uncertainty intervals should become a standard practice in the reporting of results from PMS models

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

Abstract 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

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

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

Abstract 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

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

Abstract 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

Multiple sclerosis in Canada 2011 to 2031: results of a microsimulation modelling study of epidemiological and economic impacts

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, 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 4 051 cases in 2011 to 4 794 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$2 500 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$1 300 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

La sclérose en plaques au Canada, 2011-2031 : résultats d’une étude de modélisation par microsimulation des répercussions épidémiologiques et économiques

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