[The EPI-SCAN survey to assess the prevalence of chronic obstructive pulmonary disease in Spanish 40-to-80-year-olds: protocol summary].

BACKGROUND AND OBJECTIVES: Chronic obstructive pulmonary disease (COPD) causes considerable morbidity and mortality in Spain. The 1997 IBERPOC study, applying the old criteria of the European Respiratory Society, reported a COPD prevalence of 9.1% in the adult population of Spain. The Epidemiologic Study of COPD in Spain (EPI-SCAN) aims to determine the current prevalence of COPD in residents of Spain aged 40-80 years and to estimate changes over the past 10 years. Secondary objectives are, among others, to describe the current prevalence of smoking and changes in COPD prevalence relative to previous studies; to describe treatments received by patients, quality of life, and the BODE index (body mass index, obstruction of airflow, dyspnea, and exercise tolerance); and to measure inflammatory markers in blood and exhaled-breath condensate. PATIENTS AND METHODS: EPI-SCAN is a population-based, cross-sectional epidemiologic study targeting the general population of Spain aged between 40 and 80 years. Participating centers were located in Barcelona, Burgos, Cordoba, Huesca, Madrid, Oviedo, Seville, Valencia, Vic, and Vigo. All subjects filled in an extensive questionnaire to collect social, demographic, and clinical information. Slow and forced spirometry tests before and after a bronchodilator test were also undertaken. Additionally, selected subjects performed a 6-minute walk test and answered generic and specific quality-of-life questionnaires, as well as an activities-of-daily-living questionnaire. Exhaled-breath condensate and blood samples were also collected from these subjects for measurement of inflammatory and other biomarkers.