Prevalence and Severity of Asthma Symptoms in Students of Tehran and Rasht: Phase III ISAAC Study

This study is a part of the third phase of the "International Study of Asthma and Allergy in Childhood" (ISAAC) aiming to study the prevalence and severity of asthma symptoms among children of Rasht and Tehran. This analytical cross-sectional study assessed Rasht and Tehran students in two age groups (6-7 and 13-14 years) during 2001-2002. After performing statistical analysis, prevalence of asthma symptoms was compared between the students form the two cities and was evaluated in both sexes and age groups by using the Chi-square test. A total of 12,214 students from both Rasht and Tehran participated in this study. History of wheezing and asthma were significantly higher among Rasht students. Prevalence of wheezing, speech limitation due to wheezing, wheezing during exercise and dry nocturnal cough were higher among 13-14 year olds in both cities. History of wheezing and exercise wheezing were higher in 6-7 year-old girls living in Tehran. However, prevalence of the aforementioned symptoms and prevalence of asthma were higher in total boys residing in Rasht. Also, prevalence of asthma, wheezing during exercise and dry nocturnal cough were higher in 13-14 year old boys in Rasht. No significant difference was found in this regard between Tehran girls and boys in this age group. Prevalence of asthma and some of its symptoms was significantly higher among Rasht students compared to those residing in Tehran.