Prevalence of chronic bronchitis in the children of Lisbon.

Portugal is one of the European countries with the highest mortality from Chronic Bronchitis (CB). This constitutes a severe problem as CB is one of the main causes of absenteeism and incapacity. To determine the prevalence of this disease, an epidemiological study was planned. The first part of this study involved the children of Lisbon because of the large number of children attending chest clinics for respiratory symptoms, because a similar study is being carried out in Europe by WHO in children from 8 to 10 years of age and because of the importance that this type of study in children may have in the prediction of the development of CB in adults. The study consisted in a standard questionnaire (WHO), a physical examination based on the CECA questionnaire, an ENT examination, a simple respiratory function test and a 70 mm microradiograph of the chest. 4148 children of both sexes, whose ages ranged from 6 to 14 were studied. The operational diagnosis of CB was based on the presence of chronic cough for the past 2 years, for at least 3 months and nearly every day during the Autumn and Winter months. The prevalence of CB in the overall population was 4.9%. The global analysis of the data collected seems to show the following: - Measles and whooping cough contribute to the incidence of CB. --Socio-economic conditions probably contribute to the increase in the incidence of CB. --A high incidence of ENT pathology was found in CB. --Atmospheric pollution does not appear to influence the incidence of CB.