[European study on asthma. Prevalence of bronchial hyperreactivity and asthma in young adults from 5 Spanish areas. Spanish Group of the European Study on Asthma].

BACKGROUND: The European Study on Asthma is a multicentric survey designed to determine variations in the prevalence of asthma and its determinants in Europe. The first phase of the study in Spain, by means of a short questionnaire, allowed to estimate the prevalence of symptoms related to asthma in representative samples of five Spanish areas: Albacete, Barcelona, Galdakao, Huelva and Oviedo. MATERIAL AND METHODS: The annual prevalence of symptoms related to asthma was determined with a respiratory questionnaire adapted from the IUATLD questionnaire. Participants performed a forced spirometry and bronchial hyperresponsiveness was measured through a methacholine challenge. A hyperreactive individual was defined as a subject with a fall in FEV1 of 20% or more during the challenge (cumulative dose of inhaled methacholine of 5.117 mumols) or extrapolating to 8 mumols. RESULTS: The prevalence of bronchial hyperresponsiveness ranged from 8.3% in Galdakao (95% CI 5.5-11.2) to 31.7% in Albacete (95% CI 28.6-36.6). The prevalence of asthma, defined as presence of bronchial hyperresponsiveness and symptoms related to asthma was: 4.7% in Albacete (95% CI 2.4-6.9); 3.5% in Barcelona (95% CI 0.7-6.2); 1.1% in Galdakao (95% CI 0.0-2.2); 1.0 in Huelva (95% CI 0.0-2.2); and 1.7 in Oviedo (95% CI 0.0-3.3). Different definitions of asthma produced variations of 3.1 to 4.7 fold in the prevalence of asthma between the five participating areas. CONCLUSIONS: Asthma is a common disorder in Spain and there are substantial variations in the prevalence of bronchial hyperresponsiveness and asthma between the five Spanish areas surveyed.