Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain.

Background:  Most studies show a steep increase in asthma prevalence in the last decades, although few studies had applied the same methodology. Recent reports point out the possibility that the epidemic has come to an end. We have studied the prevalence of asthma in a very large sample of children, repeating the study eight years apart. Methods:  Repeated cross-sectional studies using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol in a sample of Spanish schoolchildren 6–7 (parent-reported) and 13–14 (self-reported) years old in 1994–95 (phase I) and 2002–2003 (phase III). The number of participants was 42 417 in phase I and 42 813 in phase III. The participat…