[The IBERPOC project: an epidemiological study of COPD in Spain. Scientific Committee of the IBERPOC study].

The aim of the IBERPOC study is to determine the prevalence of chronic obstructive pulmonary disease in Spain, to collect data on its management, the degree of variability in diagnosis, treatment and quality of life, and to estimate the mean annual direct health costs for these patients. IBERPOC is a multicentric transversal epidemiologic study that selects participants from populations corresponding to geographic and/or administrative areas using a probabilistic formula. Included are both males and females between 40 and 69 years of age who are residents in the study area and living outside institutions. This article describes the study design, sample selection criteria, the method and its application, and control systems used to prevent errors in patient selection and in pulmonary function testing. The schedule for data analysis is also included.