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BackgroundAs atmospheric greenhouse gas concentrations continue to rise, temperature and humidity will increase further, causing potentially dire increases in human heat stress. On physiological and biophysical grounds, exposure to higher levels of humidity should worsen heat stress by decreasing sweat evaporation. However, population-scale epidemiological studies of heat exposure and response often do not detect associations between high levels of humidity and heat-related mortality or morbidity. These divergent, disciplinary views regarding the role of humidity in heat-related health risks limit confidence in selecting which interventions are effective in reducing health impacts and in projecting future heat-related health risks.ObjectivesVia our multidisciplinary perspective we seek to a) reconcile the competing realities concerning the role of humidity in heat-related health impacts and b) help ensure robust projections of heat-related health risks with climate change. These objectives are critical pathways to identify and communicate effective approaches to cope with present and future heat challenges.DiscussionWe hypothesize six key reasons epidemiological studies have found little impact of humidity on heat-health outcomes: a) At high temperatures, there may be limited influence of humidity on the health conditions that cause most heat-related deaths (i.e., cardiovascular collapse); b) epidemiological data sets have limited spatial extent, a bias toward extratropical (i.e., cooler and less humid), high-income nations, and tend to exist in places where temporal variations in temperature and humidity are positively correlated; c) analyses focus on older, vulnerable populations with sweating, and thus evaporative, impairments that may be further aggravated by dehydration; d) extremely high levels of temperature and humidity (seldom seen in the historical record) are necessary for humidity to substantially impact heat strain of sedentary individuals; e) relationships between temperature and humidity are improperly considered when interpreting epidemiological model results; and f) sub-daily meteorological phenomena, such as rain, occur at high temperatures and humidity, and may bias epidemiological studies based on daily data. Future research must robustly test these hypotheses to advance methods for more accurate incorporation of humidity in estimating heat-related health outcomes under present and projected future climates. https://doi.org/10.1289/EHP11807.

Background Precipitation anomalies are associated with a number of poor health outcomes. One potential consequence of precipitation extremes is human geographic mobility. We evaluated the associations between precipitation anomalies (droughts and heavy rains) and short-term mobility in 23 sub-Saharan African countries by linking satellite data on precipitation to cross-sectional representative surveys. Methods Using data from 23 Demographic and Health Surveys from 2011 to 2017, we estimated the associations between deviations in long-term rainfall trends and short-term mobility among 294,539 women and 136,415 men over 15 years of age. We fit multivariable logistic regression models to assess potential non-linear relationships between rainfall deviations and short-term mobility, adjusting for survey month and socio-demographic covariates, and stratified by participant gender. Furthermore, we assessed whether these associations differed by marital status. Results Rainfall deviations were associated with short-term mobility among women, but not men. The relationship between rainfall deviations and mobility among women was U-shaped, such that women had increased marginal probabilities of mobility in instances of both lower and heavier precipitation. Differences between married and unmarried women were also revealed: among married women, we found positive associations between both rainfall deviation extremes (drought and heavy rains) and mobility; however, among unmarried women, there was only a positive association for heavy rains. Conclusion Precipitation anomalies were associated with short-term mobility among women, which may be in turn associated with poor health outcomes. More research with longitudinal data is needed to elaborate the associations between weather shocks, mobility, and downstream health impacts.

Supplementary Material 1

Supplementary Material 1

In recent years, a vast number of studies have been generated on the impacts caused by heat waves on the health of the population. This study analyzes how heat waves that occur between the months of October and March increase the risks of morbidity and mortality of the population of five northeastern municipalities: Belém de São Francisco, Floresta, Itacuruba, Jeremoabo, Paulo Afonso and Petrolândia. It is observed that the months of January, February and October are the ones that present the most cases of morbidity and mortality of the population and that the municipality of Belén do São Francisco presents the greatest probability of risk. A consistent positive signal was found between heat waves and cardiovascular hospitalization. We also observe an increase in temperatures in the region during the last 30 years, as evidence of a possible future risk., En los últimos años se generaron un vasto número de estudios sobre impactos que causan las olas de calor sobre la salud de la población, sin embargo, muchos de ellos fuera del país. Este estudio tiene el objetivo de analizar el impacto de olas de calor sobre la salud cardiovascular y respiratoria de la población nordestina, analizando cómo olas de calor de octubre a marzo aumentan los riesgos de morbilidad y mortalidad de la población de cinco municipios. Se observa que los meses de Enero, Febrero y Octubre son los que presentan más casos de morbilidad y mortalidad de la población y que el municipio de Belém del São Francisco presenta la mayor probabilidad de riesgo. Adicionalmente se encontró una señal positiva constante entre las olas de calor y la hospitalización cardiovascular. Se utilizó un diseño cruzado de casos estratificado para estudiar la asociación entre ola de calor y óbitos e internaciones., Nos últimos anos, um grande número de estudos tem sido gerado sobre os impactos causados pelasondas de calor na saúde da população, porém, muitos deles fora do país. Esse estudo tem como objetivoanalisar o impacto das ondas de calor na saúde cardiovascular e respiratória da população nordestina,analisando como as ondas de calor de outubro a março aumentam os riscos de morbimortalidade dapopulação de cinco municípios. Observa-se que os meses de janeiro, fevereiro e outubro são os que maisapresentam casos de morbimortalidade da população e, que o município de Belém do São Francisco,apresenta a maior probabilidade de risco. Além disso, um sinal positivo consistente foi encontradoentre as ondas de calor e a hospitalização cardiovascular. Metodologicamente, foi usado um desenhocruzado estratificado de casos para estudar a associação entre onda de calor e óbitos e hospitalizações.

Changing environmental conditions constitutes one of the greatest threats to human health by reducing agricultural yields and exacerbating the burden of undernutrition. Mozambique is a region characterized by a high dependence on agricultural productivity and an increasing prevalence of climate shocks in the form of droughts and floods. Low food availability as a result of changing environmental conditions can impair child development and long-term agricultural productivity, thus necessitating e!orts to understand and protect children’s health. Women’s empowerment is strongly associated with children’s nutritional status, such that disparities in maternal autonomy and educational attainment may explain variations in climate-related vulnerabilities in this regional context. The purpose of this research is to determine the extent climate shocks are associated with child undernutrition among di!erent populations in Mozambique by focusing on droughts and floods during the main crop growing season. In addition, this research investigates the potential of women's empowerment for mitigating climate-related vulnerabilities of children. Demographic health data is linked with regional gridded climate data using a stratified regression analysis to provide information on the impact of climate shocks on child undernutrition among livelihood subgroups of croppers and fishers. This cross-sectional study found that exposure to climate shocks during the main rainy season, from November to May, increases the risk of stunting in children under age five and that women’s empowerment may not be a mitigating factor in the protection of children’s health from climate shocks. Identifying population groups most adversely a!ected by climate change will be important for reducing social inequities and achieving the Sustainable Development Goals within Mozambique.

Additional file 7.

Additional file 1. PEP4PA_CONSORT Extension for Cluster Trials 2012 Checklist.

Additional file 4. Unadjusted regression coefficients and 95% confidence intervals (CI) for all outcomes.

Additional file 3. Qualitative tool: interview guide for the population. QualPop.

Additional file 4. Qualitative tool: interview guide for the health service providers. QualHSP.

GPS data processing for all participants in the study

Additional file 5. Marginal estimates for secondary outcomes.

Additional file 6. Sensitivity analyses.

Additional file 2. PEP4PA_TIDieR-Checklist-Word.

Additional file 3. Standardized mean differences.

Additional file 7. Cumulative per person costs for intervention and control conditions.

Additional file 6.

International audience; BACKGROUND: Emerging epidemiological evidence suggests a relationship between exposure to air pollution and dementia. However, most of the existing studies relied on health administrative databases for the diagnosis of dementia. In a large French population-based cohort (the 3C Study), we assessed the effects of particulate matter ≤2.5 µm (PM2.5), nitrogen dioxide (NO(2)) and black carbon (BC) on the risk of dementia diagnosed with reliable tools.METHODS: Participants aged ≥65 years were recruited between 1999 and 2001 and followed for 12 years. At baseline and every 2 years, dementia was suspected on the basis of the neuropsychological and neurological examination and confirmed by an independent committee of clinicians. Exposure to NO(2), BC and PM2.5 at the participants’ residential address was estimated using land use regression models. For each pollutant and year of follow-up, the 10-year moving average of past exposure was estimated. Multilevel spatial random-effects Cox proportional hazards models were used in which exposure was included as a time-varying variable. Analyses were adjusted for individual (age, sex, education, APOE4 genotype, health behaviours) and contextual (neighbourhood deprivation index) confounders.RESULTS: At baseline, the median age of the 7066 participants was 73.4 years, and 62% were women. The median follow-up duration was 10.0 years during which 791 participants developed dementia (n = 541 Alzheimer’s disease (AD) and n = 155 vascular/mixed dementia (VaD)). The 10-year moving average of PM2.5 concentrations ranged from 14.6 to 31.3 µg/m(3). PM2.5 concentration was positively associated with dementia risk: HR = 1.20, 95% CI (1.08-1.32) for all-cause dementia, 1.20 (1.09-1.32) for AD, and 1.33 (1.05-1.68) for VaD per 5 µg/m(3) PM2.5 increase. No association was detected between NO(2) or BC exposure and dementia risk.CONCLUSION: In this large cohort of older adults, long-term PM2.5 exposure was associated with increased dementia incidence. Reducing PM2.5 emissions might lessen the burden of dementia in aging populations.

Additional file 1.

Electronic cigarettes (e-cigarettes) are the preferred smoking-cessation aid in the United States; however, there is little evidence regarding long-term effectiveness among those who use them. We used the Population Assessment of Tobacco and Health Study to compare long-term abstinence between matched US smokers who tried to quit with and without use of e-cigarettes as a cessation aid. We identified a nationally representative cohort of 2,535 adult US smokers in 2014-2015 (baseline assessment), who, in 2015-2016 (exposure assessment), reported a past-year attempt to quit and the cessation aids used, and reported smoking status in 2016-2017 (outcome assessment; self-reported ≥12 months continuous abstinence). We used propensity-score methods to match each e-cigarette user with similar nonusers. Among US smokers who used e-cigarettes to help quit, 12.9% (95% confidence interval (CI): 9.1%, 16.7%) successfully attained long-term abstinence. However, there was no difference compared with matched non-e-cigarette users (cigarette abstinence difference: 2%; 95% CI: -3%, 7%). Furthermore, fewer e-cigarette users were abstinent from nicotine products in the long term (nicotine abstinence difference: -4%; 95% CI: -7%, -1%); approximately two-thirds of e-cigarette users who successfully quit smoking continued to use e-cigarettes. These results suggest e-cigarettes may not be an effective cessation aid for adult smokers and, instead, may contribute to continuing nicotine dependence.

L’équité en santé est largement identifiée comme un objectif auquel les politiques et activités de santé publique doivent répondre en priorité, mais dont la définition varie considérablement. Dans ce chapitre, nous proposons une définition de l’équité en santé qui fait référence à la distribution des bénéfices des politiques publiques. Dans ce chapitre nous présentons différentes méthodes de mesures des inégalités de santé, leur application à l’évaluation des effets des interventions à travers l’exemple de l’effet de l’exemption du paiement des frais de soins sur l’accès aux soins obstétricaux dans le cadre d’un exemple simulé. Ces mesures incluent notamment l’indice de concentration et l’indice de Theil. Enfin, nous proposons différentes approches pour les appliquer à l’évaluation des effets des interventions donc à l’équité incluant une approche simple et une base sur l’utilisation de méthodes quasi-expérimentales. L’évaluation de l’équité en santé publique est importante pour s’assurer que, d’une part, des interventions ne contribuent pas à augmenter les inégalités de santé et qu’elles répondent aux objectifs énoncés dans le cadre d’interventions visant à réduire les inégalités de santé. Health equity is considered a priority for public health interventions and policies, but the concept of an equitable intervention varies in definition. We define an equitable intervention as one that has heterogeneity in its effects, and provides greater benefits for subgroups or territories of a population that have been defined as vulnerable. In this chapter, we assess the impact of an intervention establishing free obstetric care (childbirth costs excluded) on increasing equity and access to care. We notably present the concentration index and the Theil Index. Simulated data from population surveys is used to discuss important issues regarding measurement of inequalities and different indicators that can be used in evaluating the equitability of an intervention. Lastly, two evaluation strategies are discussed: a simple evaluation approach to illustrate the application of inequality measurement methods and an approach based on quasi-experimental designs. These tools to assess public health equity is important to ensure that interventions meet objectives to reduce inequalities and prevent them from contributing to increasing health disparities. La equidad en salud es ampliamente identificada como un objetivo al que las políticas y actividades de salud pública deben responder como una prioridad, pero cuya definición varia considerablemente. En este capítulo proponemos una definición de equidad en salud que se refiere a la distribución de los beneficios de las políticas públicas. En este capítulo se presentan diferentes métodos para medir las desigualdades en salud, su aplicación a la evaluación de los efectos de las intervenciones a través del ejemplo del efecto de la exención de las tasas de atención sanitaria sobre el acceso a la atención obstétrica en un ejemplo simulado. Estas medidas incluyen el indice de concentración y el indice de Theil. Finalmente, proponemos diferentes enfoques para aplicarlos a la evaluación de los efectos de las intervenciones y, por lo tanto, a la equidad, incluyendo un enfoque simple y una base sobre el uso de métodos cuasi-experimentales. La evaluación de la equidad en salud pública es importante para garantizar que, por una parte, las intervenciones no contribuyan a aumentar las desigualdades en salud y, por otra parte, que cumplan los objetivos establecidos en las intervenciones para reducir las desigualdades en salud.

Les méthodes quasi-expérimentales (MQE) sont des alternatives aux essais contrôlés randomisés, qui permettent, en se basant sur le modèle contre-factuel, d’évaluer les effets d’interventions en exploitant des expérimentations naturelles. L’objectif de ce chapitre est d’introduire deux MQE, à savoir la me la méthode de Différence dans les Différences (DD) ainsi que l’approche de Régression avec Discontinuité (RD). Leur application afin d’évaluer l’effet de l’âge légal minimum sur la consommation d’alcool chez les jeunes est ensuite présentée. Sont présentées toutes les étapes nécessaires et les codes statistiques (pour R et Stata) permettant de reproduire ce type d’analyse. Ces approches constituent de bonnes solutions lorsque des essais contrôlés randomisés sont impossibles ou difficiles à mener, permettant de s’assurer que des objectifs d’un programme de santé publique sont bel et bien atteints, de décider quant au maintien, à la modification ou à l’arrêt d’interventions existantes et de s’assurer que les ressources publiques sont utilisées de manière efficace. Quasi-experimental methods have been developed to evaluate ‘naturel experiments, ’ an alternative design to randomized controlled trials that relies on the notion of the counterfactual to estimate causal effects. The objective of this chapter is to describe quasi-experimental methods, apply them empirically to an example, and provide all elements of the evaluation, allowing the reader to reproduce these analyses (in R and Stata) in their given context. The main objective of this type of policy evaluation is to attribute a causal effect of an intervention on a health indicator. We apply these methods to estimate the impact of a policy raising minimum legal drinking on alcohol consumption among young people. Two types of quasi-experimental methods are used in this evaluation: the Différence in Différences (DD) method and the discontinuous regression (RD) approach. We show that these approaches can be good solutions to evaluate policies when randomized controlled trials are impossible. These evaluation tools can be used to ensure that policies contribute to the improvement of population health, to inform and décidé whether to maintain, modify or discontinue existing interventions and to ensure public resources are used effectively. Se han desarrollado métodos cuasi-experimentales para evaluar los « experimentos naturales », un diseño alternativo a los ensayos controlados aleatorios que se basa en la noción de lo contrafactual para estimar los efectos causales. El objetivo de este capítulo es describir métodos cuasiexperimentales, aplicarlos empíricamente a un ejemplo y proporcionar todos los elementos de la evaluación, permitiendo al lector reproducir estos anâlisis (en R y Stata) en su contexto dado. El objetivo principal de este tipo de evaluación de políticas es atribuir un efecto causal de una intervención a un indicador de salud. Aplicamos estos métodos para estimar el impacto de una política que aumenta el consumo mínimo legal de alcohol en el consumo de alcohol entre los jóvenes. En esta evaluación se utilizan dos tipos de métodos cuasiexperimentales: el método de la Diferencia de Diferencias (DD) y el enfoque de regresión discontinua (RD). Demostramos que estos enfoques pueden ser buenas soluciones para evaluar las políticas cuando los ensayos controlados aleatorios son imposibles. Estas herramientas de evaluación pueden utilizarse para garantizar que las políticas contribuyan a mejorar la salud de la población, para informar y decidir si se mantienen, modifican o interrumpen las intervenciones existentes y para garantizar que los recursos públicos se utilicen de manera eficaz.

Une couverture universelle des soins de santé en 2030 pour tous les êtres humains, du Nord au Sud ? Réaliser cet objectif de développement durable aussi ambitieux que nécessaire exigera une exceptionnelle volonté politique, mais aussi de solides données probantes sur les moyens d’y arriver, notamment sur les interventions de santé mondiale les plus efficaces. Savoir les évaluer est donc un enjeu majeur. On ne peut plus se contenter de mesurer leur efficacité : il nous faut comprendre pourquoi elles l’ont été (ou pas), comment et dans quelles conditions. Cet ouvrage collectif réunissant 27 auteurs et 12 autrices de différents pays et de disciplines variées a pour but de présenter de manière claire et accessible, en français, un florilège d’approches et de méthodes avancées en évaluation d’interventions : quantitatives, qualitatives, mixtes, permettant d’étudier l’évaluabilité, la pérennité, les processus, la fidélité, l’efficience, l’équité et l’efficacité d’interventions complexes. Chaque méthode est présentée dans un chapitre à travers un cas réel pour faciliter la transmission de ces savoirs précieux.

International audience; Background: Several studies highlighted the impact of community-based interventions whose purpose was to reduce the vectors' breeding sites. These strategies are particularly interesting in low-and-middle-income countries which may find it difficult to sustainably assume the cost of insecticide-based interventions. In this case study we determine the spatial distribution of a community-based intervention for dengue vector control using different entomological indices. The objective was to evaluate locally where the intervention was most effective, using spatial analysis methods that are too often neglected in impact assessments.Methods: Two neighbourhoods, Tampouy and Juvenat in Ouagadougou, Burkina Faso, were chosen among five after a survey was conducted, as part of an assessment related to the burden of dengue. As part of the community-based intervention conducted in Tampouy between August and early October 2016, an entomological survey was implemented in two phases. The first phase consisted of a baseline entomological characterization of potential breeding sites in the neighbourhood of Tampouy as well as in Juvenat, the control area. This phase was conducted in October 2015 at the end of the rainy season. The mosquito breeding sites were screened in randomly selected houses: 206 in Tampouy and 203 in Juvenat. A second phase took place after the intervention, in October 2016. The mosquito breeding sites were investigated in the same yards as during the baseline phase. We performed several entomological analyses to measure site productivity as well as before and after analysis using multilevel linear regression. We used Local Indicators of Spatial Association (LISAs) to analyse spatial concentrations of larvae.Results: After the intervention, it is noted that LISAs at Tampouy reveal few aggregates of all types and the suppression of those existing before the intervention. The analysis therefore reveals that the intervention made it possible to reduce the number of concentration areas of high and low values of pupae.Conclusions: The contribution of spatial methods for assessing community-based intervention are relevant for monitoring at local levels as a complement to epidemiological analyses conducted within neighbourhoods. They are useful, therefore, not only for assessment but also for establishing interventions. This study shows that spatial analyses also have their place in population health intervention research.

Additional file 2. Questionnaire Endline.

Additional file 1.

Additional file 1: Table S1. Oaxaca-Blinder decomposition of differences in daily smoking between high school students and apprentices in the 2008 sample without the variables “parental smoking”: estimates and percentage contributions. Table S2. Oaxaca-Blinder decomposition of differences in daily smoking between high school students and apprentices in 2008 without the variable “money received”: estimates and percentage contributions. Table S3. Oaxaca-Blinder decomposition of differences in daily smoking between high school students and apprentices in the 2008, 2017-A and 2017-B samples. Sensitivity analysis with one model for each independent variable: estimates and percentage contributions.

BackgroundExposure to fine particulate matter (PM2.5) during pregnancy has been shown to be associated with reduced birth weight and racial/ethnic minorities have been found to be more vulnerable. Previous studies have focused on the mean value of birth weight associated with PM2.5, which may mask meaningful differences. We applied a quantile regression approach to investigate the variation by percentile of birth weight and compared non-Hispanic (NH) Black, NH White, and Hispanic mothers.MethodsData for singleton births in California from October 24, 2005 to February 27, 2010 were collected from the birth records accessed from the California Department of Public Health. Air pollution monitoring data collected by the California Air Resources Board and interpolated for each zip code using an inverse-distance weighting approach, and linked to maternal zip code of residence reported on the birth certificate. Multilevel linear regression models were conducted with mother's residential zip code tabulation area as a random effect. Multilevel quantile regression models were used to analyze the association at different percentiles of birth weight (5th, 10th, 25th, 50th, 75th, 90th, 95th), as well as examine the heterogeneity in this association between racial/ethnic groups.ResultsLinear regression revealed that a 10 μg/m3 increase in PM2.5 exposure during pregnancy is associated with a mean birth weight decrease of 7.31 g [95% confidence interval (CI): 8.10, 6.51] and NH Black mothers are the most vulnerable. Results of the quantile regression are not constant across quantiles. For NH Black mothers whose infants had the lowest birthweight of less than 2673 g (5th percentile), a 10 μg/m3 increase in PM2.5 exposure is associated with a decrease of 18.57 g [95% CI: 22.23, 14.91], while it is associated with a decrease of 7.77 g [95% CI: 8.73, 6.79] for NH White mothers and 7.76 [8.52, 7.00] decrease for Hispanic mothers at the same quantile.ConclusionResults of the quantile regression revealed greater disparities, particularly for infants with the lowest birth weight. By identifying vulnerable populations, we can promote and implement policies to confront these health disparities.

Table S1. Number of steps taken per minute during episodes of transfer in public transport trips represented as point locations in the mobility survey (RECORD MultiSensor Study). Table S2. Average number of trips per individual per day according to the main mode in the trip and according to the geographic location of the residence (RECORD MultiSensor Study). (DOCX 17 kb)

© The Author 2017. Published by Oxford University Press. Background: Despite strong efficacy in randomized trials, the population effectiveness of pharmaceutical aids in long-term smoking cessation is lacking, possibly because of confounding (factors that are associated with both pharmaceutical aid use and difficulty quitting). Matching techniques in longitudinal studies can remove this confounding bias. Methods: Using the nationally representative Tobacco Use Supplement to the Current Population Survey (TUS-CPS), we assessed the effectiveness of medications to aid quitting among baseline adult smokers who attempted to quit prior to one year of follow-up in two longitudinal studies: 2002-2003 and 2010-2011. Pharmaceutical aid users and nonusers with complete data (n ¼ 2129) were matched using propensity score models with 12 potential confounders (age, sex, race-ethnicity, education, smoking intensity, nicotine dependence, previous quit history, self-efficacy to quit, smoke-free homes, survey year, and cessation aid use). Using matched data sets, logistic regression models were fit to assess whether use of any individual pharmaceutical aid increased the proportion of patients who were abstinent for 30 days or more at follow-up. Results: Propensity score matching markedly improved balance on the potential confounders between the pharmaceutical aid use groups. Using matched samples to provide a balanced comparison, there was no evidence that use of varenicline (adjusted risk difference [aRD] ¼ 0.01, 95% confidence interval [CI] ¼ -0.07 to 0.11), bupropion (aRD ¼ 0.02, 95% CI ¼ -0.04 to 0.09), or nicotine replacement (aRD ¼ 0.01, 95% CI ¼ -0.03 to 0.06) increased the probability of 30 days or more smoking abstinence at one-year follow-up. Conclusions: The lack of effectiveness of pharmaceutical aids in increasing long-term cessation in population samples is not an artifact caused by confounded analyses. A possible explanation is that counseling and support interventions provided in efficacy trials are rarely delivered in the general population.

Distribution of the “share of total commuting time spent active” among active commuters, N = 537. (DOCX 13 kb)

Sensitivity analysis: association between neighborhood education, distance to work* and the probability of reporting any active commuting (N = 1169). (DOCX 14 kb)

Sensitivity analysis: association between neighborhood education, distance to work* and share of total commuting time spent active among active commuters (N = 537). (DOCX 13 kb)

Additional analysis: association between neighborhood education level and the absolute time of active commuting, N = 537a. (DOCX 12 kb)

Les changements climatiques constituent un enjeu important en santé publique. En effet, une hausse des températures provoquera une hausse de la mortalité attribuable à la chaleur. En outre, certaines populations et territoires sont particulièrement vulnérables aux effets de la chaleur. Il est donc nécessaire de les identifier clairement ainsi que les impacts futurs pour orienter avec équité les politiques publiques aujourd’hui et à l’avenir. L’objectif de cette thèse est de documenter les facteurs de vulnérabilité à la chaleur dans le présent et les éléments permettant leur prise en compte pour l’avenir dans le contexte des changements climatiques. Quatre étapes ont été menées pour répondre à cet objectif : a) Mener une revue systématique et une méta-analyse des facteurs de vulnérabilité face aux risques de mortalité en lien avec la chaleur ; b) Analyser si l’exposition chronique à la pollution atmosphérique modifie la relation entre la chaleur et la mortalité dans un contexte urbain (Paris) et explorer la double interaction avec la défaveur sociale ; c) Développer une méthode de quantification des impacts liés à la chaleur en lien avec les changements climatiques en intégrant une grande diversité de simulations climatiques ; d) Estimer les inégalités d’années de vies perdues attribuables à la chaleur et leurs projections futures dans deux contextes distincts (Montréal et Paris) et comparer ces inégalités. Cette thèse a permis de mettre en évidence sur la base de la littérature épidémiologique les groupes de population qui sont les plus vulnérables face aux effets de la chaleur et de montrer qu’il y a plusieurs divergences par rapport aux recommandations émises par les institutions de santé publique vis-à-vis de l’identification de populations vulnérables. Cette thèse a permis également d’identifier l’exposition chronique à la pollution atmosphérique comme nouveau facteur de vulnérabilité à la chaleur et que cette vulnérabilité était encore plus prononcée lorsqu’il s’agissait de populations défavorisées socialement. Puis, une méthode permettant de quantifier l’impact des changements climatiques sur les décès attribuables à la chaleur et ses sources d’incertitudes a été développée, et a permis de mettre en évidence que la probabilité que les changements climatiques conduisent à une augmentation de la mortalité en lien avec la chaleur est très forte. Cette méthode a ensuite été utilisée pour estimer que l’augmentation de la température conduira à une augmentation des inégalités sociales d’années de vie perdues à la fois à Montréal et à Paris, l’effet des changements climatiques sur l’accroissement de ces inégalités étant plus fort à Montréal qu’à Paris. Cette thèse, en se basant sur diverses méthodes épidémiologiques, a permis dans l’ensemble de clarifier quelles populations étaient particulièrement à risque face aux effets de la chaleur et de questionner les recommandations émises par les organismes tels que l’OMS. Elle a également permis de montrer l’effet des changements climatiques sur l’évolution de vulnérabilités face à la chaleur pour inciter dès aujourd’hui la mise en place de politiques publiques équitables et limiter l’impact des changements climatiques sur l’accroissement des inégalités de santé., Climate change is an important public health threat. An increase in temperatures will lead to an increase in mortality attributable to temperature. In addition, some populations and territories are particularly vulnerable to the impact of increases in heat. It is thus necessary to identify these populations and territories as well as examine future heat-related health impacts in order to recommend equity-oriented policies today and in the future. The general objective of this thesis is to document current and future heat-related vulnerability factors in the context of climate change. In order to address this general objective, the thesis involved four components: a) to conduct a systematic review and a meta-analysis to assess the heterogeneity in the heat-mortality associations with respect to individual and contextual population characteristics; b) to identify whether and how the magnitude of mean temperature effects on all-cause mortality were modified by chronic air pollution exposure, social deprivation, and a combination of these two dimensions; c) to develop a method to quantify the climate change impacts on heat-related mortality using climate modeling; d) to assess historical and future social disparities in years of life lost caused by ambient temperature in Montreal and Paris, and compare these estimates as well as the impact of climate change on social disparities between the two cities. This thesis highlights which populations are more vulnerable to heat and shows that several differences exist with regard to guidelines from international public health institutions for the identification of vulnerable populations. This thesis also identified chronic air pollution exposure as a new vulnerability factor in heat-related mortality and that it has a double interaction with social deprivation. Furthermore, in this thesis a novel method to quantify future heat-related mortality was developed which emphasized the strong evidence of an increase in heat-related mortality under climate change. This method was then applied to estimate the increase in daily years of life lost social disparities in both Montreal and Paris under climate change which showed that this increase would be greater in Montreal compared to Paris in the future. Thus, this thesis which used a variety of epidemiologic methods has clarified which populations are particularly vulnerable to heat impacts and challenges guidelines for the identification of vulnerable populations from international public health institutions. It has also highlighted the climate change impacts on health inequalities and aims to reorient equity-focused policies., Thèse réalisée en cotutelle avec Université Paris 11 (Ecole Doctorale 420)

Additional file 1. SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*.

Additional file 1. SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*.