[Relevance of the health insurance databases to study spatial disparities in asthma prevalence: A study in southeastern France]

Data on asthma prevalence at a small-area level would be useful to set up and monitor French local public health policies. This study, based on drug reimbursement databases in southeastern France, aimed to (1) compare asthma-like disorders prevalence estimated by using three different indicators; (2) study sociodemographic characteristics associated with these indicators; (3) verify whether these indicators are equivalent to study geographical disparities of the asthma-like disorders prevalence at a small-area level.The study was conducted among the beneficiaries of the National Health Insurance Fund aged 18-44 years residing in southeastern France in 2010 (n=1,371,816). Using data on asthma drugs reimbursements (therapeutic class R03), we built three indicators to assess asthma-like disorders prevalence: at least 1, 2 or 3 purchase(s) in 2010. We analyzed sociodemographic characteristics associated with these indicators, and their geographical disparities at a small-area level using multilevel logistic regression models.The crude asthma-like disorders prevalence varied between 2.6 % and 8.4 % depending on the indicator. It increased with age, was higher for women than for men, and among low-income people for all three indicators. We measured significant geographical disparities. Areas with high prevalence rates were the same regardless of the indicator.The indicators built in this study can be useful to identify high prevalence areas. They could contribute to launch discussion on environmental health issues at the local level.