Role of comorbid conditions in asthma hospitalizations in the south of France

Background Reasons for asthma hospitalizations are dynamic and complex. Comorbid conditions are important contributors to most chronic diseases today. We aim to characterize and describe risk factors associated with hospitalizations due to asthma in the Languedoc-Roussillon region (France) in 2009. Methods Programme de Medicalisation des Systemes d'Information (PMSI) data records from 2009 were sorted using selected International Classification of Diseases (ICD10) codes eliciting three groups of asthma hospitalizations according to acute severity. All available data including demographics, comorbid conditions, past hospitalizations either related or unrelated to asthma, seasonality and distance to medical facilities were used to compare the subjects within the three groups. Results One thousand two hundred and eighty-nine hospitalizations due to asthma exacerbation were found, concerning 1122 patients. We observed significant differences within the groups, using univariate analysis, concerning duration of hospitalizations (mean +/- SD, 4.9 +/- 5.9days vs 6.4 +/- 6.8 vs 15.8 +/- 16.8, P<0.001), deaths (percentage, 0.03% vs 1.50% vs 9.20%, P<0.001) and numbers of comorbid conditions (0.80 +/- 0.95 vs 0.75 +/- 0.97 vs 1.74 +/- 1.36, P<0.001). Recurrent admissions for asthma during the period 20062008 were significantly more frequent in the more severe group (1.93 +/- 3.91 vs 2.56 +/- 4.47 vs 2.81 +/- 3.97, P=0.006). In the multivariate model, age and number of comorbid conditions were independently associated with severe hospitalizations and deaths. Conclusions Asthma hospitalizations can be appropriately assessed using PMSI coding databases. In this study, age and the presence of comorbid conditions are the major risk factors for asthma hospitalizations and deaths.