Presentation of the PAISIM Collaborative Project: Relations Between Short-Term Exposures of Air Pollution, Socioeconomic Inequalities in Health and the Onset of Myocardial Infarction

P-022 Abstract: In most industrialized countries, socio-economic gradients in morbidity and mortality rates for coronary heart disease, notably for acute myocardial infarction (AMI), are relatively well documented, e.g. a lower socio-economic status (SES) represents a higher risk factor for AMI. These socio-economic inequalities in health can be partly explained by biological and behavioural factors (smoking, alcohol consumption, diabetes, hypertension…), psychosocial factors (stress, working environment…), material living circumstances and access to health care. Another part of these inequalities may be explained by environmental exposures, especially exposure to urban air pollution. The aim of the PAISIM project is to investigate and to test the relationships between socio-economic status, onset of myocardial infarction and short-term exposures of air pollutants on an ecological basis. This approach was investigated only in few studies and never in France to date. Our project will be carried out in an eastern French large urban area. The statistical unit will be the IRIS 2000, the smallest geographic area for which socio-economic data are available (National Institute for Statistics and Economic Studies - INSEE). Daily counts of myocardial infarction between 2000 and 2002 will be provided mainly by the local population-based coronary disease Registry. All the cases will be allocated to their IRIS of residence. We will also discuss the possibility of using data from emergency and rescue services. For each IRIS, hourly concentrations of PM10, O3, NO2 and SO2 will be estimated from the local air quality monitoring association using essentially a deterministic model, ADMS-Urban. A set of composite indexes of SES will be constructed and compared from demographic and socio-economic data of the 1999 national population census supplied by INSEE. To assess the role of SES on the spatial distribution of air pollutants levels and on the risk of myocardial infarction, we will use both case crossover and time series designs. These studies will allow us to test the potential modifying effect of SES on the relationship “air pollutants - myocardial infarction” by the addition of an interaction term in the model or by stratified analyses. The whole of these analyses will be adjusted for potential confounders (long-term trends, seasonality, weather, influenza episodes, day-of-week…) and will take into account different lags (0 to 5 days) between the exposure to pollutants and the onset of myocardial infarction.