The European Community Respiratory Health Survey.

The European Community Respiratory Health Survey (ECRHS) was planned to answer specific questions about the distribution of asthma and health care given for asthma in the European Community. Specifically, the survey is designed to estimate variations in the prevalence of asthma, asthma-like symptoms and airway responsiveness; to estimate variations in exposures to known or suspected risk factors for asthma, and assess to what extent these variations explain the variations in the prevalence of disease; and to estimate differences in the use of medication for asthma. The protocol provides specific instructions on the sampling strategy adopted by the survey teams, as well as providing instructions on the use of questionnaires, the tests for allergy, lung function measurements, tests of airway responsiveness, and blood and urine collection. The principal data collection sheets and questionnaires are provided in the appendices, together with information on coding and quality control. The protocol is published as a reference for those who wish to know more of the methods used in the study, and also to give other groups who wish to collect comparable data access to the detailed methodology.