Sex-specific trends in prevalence of childhood asthma over 30 years in Patras, Greece

Aim: According to four surveys conducted during 1978-2003, the prevalence of childhood asthma and wheezing has risen in the city of Patras, Greece, albeit at a decelerating rate. We examined sex-specific wheeze and asthma prevalence in the same urban environment in 2008. Methods: A cross-sectional parental questionnaire survey was performed in 2008 among third and fourth grade schoolchildren (8-9 year old), which was identical to previously conducted surveys in 1978 (n = 3003), 1991 (n = 2417), 1998 (n = 3076) and 2003 (n = 2725). Results: The prevalence of current wheeze and asthma in 1978, 1991, 1998, 2003 and 2008 (n = 2688) was 1.5%, 4.6%, 6.0%, 6.9% and 6.9%, respectively (p for trend < 0.001). Respective values for lifetime (ever had) wheeze and asthma in the 1991-2008 surveys were 8.0%, 9.6%, 12.4% and 12.6% (p for trend < 0.001). The male:female ratio of current and lifetime wheeze and asthma increased during the 30-year surveillance period (p for trend < 0.001). Irrespective of sex, diagnosed asthma declined among current wheezers by 17% (p < 0.001), but not among non-current ones (6.7%, p = 0.16) during 2003-2008. Conclusions: Childhood wheeze and asthma have reached a plateau in an urban environment in Greece, while the male:female ratio increased. Asthma diagnosis declined among schoolage but not preschool wheezers during 2003-2008.