Prevalence of asthma among schoolchildren in Patras, Greece: four questionnaire surveys during 1978-2003

Background: The prevalence of asthma and wheezing has risen during the past four decades. Recent reports suggest that the ''asthma epidemic'' has reached a plateau. Objective: To examine further trends in the prevalence of childhood diagnosed asthma and wheezing in an urban environment in Greece. Methods: A population-based cross-sectional parental questionnaire survey was repeated among third-grade and fourth-grade school children (8-10 years) of public primary schools in 2003 in the city of Patras, Greece, by using methods identical to that of surveys conducted in 1978 (completed questionnaires, n = 3003), 1991 (n = 2417) and 1998 (n = 3076). Results: 2725 questionnaires were completed in the 2003 survey. The prevalence rates of current asthma and/or wheezing in 1978, 1991, 1998 and 2003 were 1.5%, 4.6%, 6% and 6.9%, respectively (p for trend < 0.001). The lifetime prevalence of asthma and/or wheezing in the three more recent surveys was 8%, 9.6% and 12.4%, respectively (p for trend < 0.001). The male: female ratios of current asthma and/ or wheezing in the four surveys were 1.14:1, 1.15:1, 1.16:1 and 1.22:1, respectively. The proportion of those with wheezing diagnosed with asthma has increased during the study period, more so among non-current children with asthma. Conclusions: Our findings show a continuous increase in the prevalence of asthma and wheezing among preadolescent children in Patras, Greece, over 25 years, albeit at a decelerating rate. There seems to be a true increase in wheezing, despite some diagnostic transfer, particularly among younger children. The male predominance of the disease has persisted in the population of this study.