Incidence and risk factors of acute rhinosinusitis in an urban population: a GA²LEN study

Introduction: The epidemiology of acute rhinosinusitis (ARS) is largely unknown, due to a lack of comparable studies with standardized diagnostic criteria. The present study, as part of the Ga²len Survey, aims to characterize the incidence and risk factors ARS in an urban population. Methods: The study was designed as a cross-sectional mail-based survey. A random sample of 5000 inhabitants was sent a questionnaire in up to three attempts. The questionnaire was constructed based on the ECRHS questionnaire for asthma and allergic rhinitis, and on the EP3OS criteria for rhinosinusitis. Additionally, patients were asked the frequency of ARS episodes, if they visited a doctor for ARS, and if antibiotics and nasal steroids were taken. Risk factors and corresponding odds ratios were estimated using binomial and multinomial logistic regression. Results: 1881 subjects (37%) returned the questionnaire, of which 54,1% were female and the median age was 45y. 25.6% of subjects were past smokers, and 23.7% were current smokers. The incidence of at least one episode of ARS was 34,0% (IQR 31,9-35,2%). Of those, 52,3% consulted a doctor, 24,0% had antibiotics, and 32,6% had nasal steroids for ARS. Logistic regression for ARS revealed significant associations with female sex, smoking history, eczema history, chronic plegm coughing, current allergic rhinitis and CRS. With multinomial regression, risk factors were evaluated for the frequency of ARS episodes. Current allergic rhinitis was associated with all frequencies of ARS episodes, and CRS increased the odds of having 2 or more episodes. Age was negatively correlated with up to 3 episodes, and female sex was associated with 2 or 3 episodes. Smoking was associated with 3 or more episodes. Visiting a doctor for ARS was associated with CRS, current allergic rhinitis and age. Age and CRS were associated with antibiotic use. The frequency of ARS episodes, current allergic rhinitis and a healthcare job were associated with nasal steroid use. Discussion: We report a 34% yearly incidence of at least one episode of ARS in an urban population. This number is strikingly higher compared to previously reported incidences, but differences in diagnostic criteria and limitations of mail-based surveys must be considered. Female sex and young age were associated with modest increases in ARS episodes. The association of smoking behavior with high numbers of ARS episodes opens perspectives on the effect of smoke on upper airway defense mechanisms