Asthma concepts and epidemiological tools for prevalence researches

Asthma, as a multifatorial disease, with high prevalence and frequent recurrence, attack people, independently of age, sex and geographical area. Because of lack of consensus about the definition of asthma, many questionnaires have been developed to standardize epidemiological criteria of suspicion and diagnosis. Among them, the European Community Respiratory Health Survey (ECRHS) is an important tool for prevalence studies on adults aged from 20 to 44 years old, that represented a methodological improvement of epidemiological surveys, turning them comparable about time and place. The objectives of this article are to comment the evolution of asthma concepts and its repercussion on epidemiological surveys, as well as to chronicle the tools used on these surveys, emphasizing the importance of ECRHS and presenting epidemiological data of asthma on 351 universitary hospital servers at Recife City -- Pernambuco -- Brazil.