The diagnosis of asthma using a self-questionnaire in those suffering from allergic rhinitis: a pharmaco-epidemiological survey in everyday practice in France

Background: All recent guidelines recommend a search for asthma utilizing both specific interrogation and pulmonary function tests in patients suffering from allergic rhinitis. Although the mandatory place of spirometry has not been confirmed, a self-questionnaire containing nine specific questions on asthma symptoms in different daily life situations was found to be capable of discriminating asthmatics from nonasthmatics in a rhinitic population. Objective: We addressed the questions of prevalence of asthma using a validated self-questionnaire and what might be the risk factors of being asthmatic according to that specific self-questionnaire. Methods: Between April 2003 and September 2004, nearly 12 000 rhinitis patients were enrolled by more than 2300 physicians (78% general practitioners, 22% ear nose and throat specialists). Patients were consulting for an exacerbation of chronic rhinitis and did not have a previous diagnosis of asthma. Both doctors and patients filled out a specific questionnaire on rhinitis and asthma. Results: Almost 30% of the patients had at least three positive answers to the self-questionnaire and could possibly be considered as asthmatics. We found five independent clinical risk factors for having >= 3 positive answers to the self-questionnaire. Severity of rhinitis (moderate-severe vs mild, OR = 1.84; 95% CI = 1.68-2.00), diagnosis of allergy (yes vs no) (OR = 1.86; 95% CI = 1.68-2.00), body mass index (<= 18.5 vs > 30) (OR = 0.51; 95% CI = 0.39-0.66), type of rhinitis (persistent vs intermittent) (OR = 1.25; 95% CI = 1.15-1.37), and patient age (<= 25 vs > 47) (OR = 0.73; 95% CI = 0.65-0.80). Conclusion: Asthma symptoms are frequent in rhinitics without a prior history of asthma. Several variables were shown to be predictive of asthma in these patients.