PREVALENCE OF ASTHMA IN ISFAHAN JUNIOR HIGH SCHOOL CHILDREN (1998-1999)
Abstract
Introduction. Asthma is the most common chronic disease in children. Unfortunately there are not exact epidemiologic data concerning the prevalence of this disorder in Iranian children. The purpose of this study was to estimate the prevalence of asthma or respiratory symptoms in Isfahan Junior high school children.
Methods. From 1998 Oct. to 1999 May. 3986 children from urban junior high schools children were selected by a proportional random cluster sampling. A self administered questionnaire prepared by International Study of Asthma and Allergies in Childhood (ISSAC) modified by several supplementary questions was distributed among the selected children. The response rate was 98.5 percent (N=3924). Of these children, 2588 pupils who had at least one positive answer referring to respiratory symptoms were invited to AL-Zahra medical center for further evaluation, but 1710 pupils (66 percent of the invited) attended the clinic and underwent complete medical interview, physical examination and post-exercise pulmonary function testing. Those children who failed to attend the clinic were examined at their schools (774 cases) and 104 absent pupils were not examined. Our criterion for the diagnosis of asthma was the positive history of wheezing and dyspnea.
Results. The overall prevalence of asthma was 19.6 percent with a male to female ratio of 1.7:1 (P<0.0001). The frequencies of wheezing ever in life and sleep disturbed by wheeze were 31.7 percent and 9.5 percent, respectively. Wheeze and rhoncus on chest auscultation while the children were examined in clinic or school was recorded in 4.2 percent and 3.5 percent of the population, respectively. Pulmonary function tests revealed FEV1:5,80 percent of predicted value (prd) in 5.9 percent, FEF 25-75£70 Percent prd in 9.6 percent and FEF75£70 percent prd in 20.5 percent of tested children. The three later findings correlated to history of wheezing and dyspnea (P < 0.0001).
Discussion. The prevalence of asthma in the students of the junior high schools of Isfahan is more than average rates reported in many parts of the world, and it seems necessary to pay more attention to poorly controlled air pollution in Isfahan as an industrial city.
Methods. From 1998 Oct. to 1999 May. 3986 children from urban junior high schools children were selected by a proportional random cluster sampling. A self administered questionnaire prepared by International Study of Asthma and Allergies in Childhood (ISSAC) modified by several supplementary questions was distributed among the selected children. The response rate was 98.5 percent (N=3924). Of these children, 2588 pupils who had at least one positive answer referring to respiratory symptoms were invited to AL-Zahra medical center for further evaluation, but 1710 pupils (66 percent of the invited) attended the clinic and underwent complete medical interview, physical examination and post-exercise pulmonary function testing. Those children who failed to attend the clinic were examined at their schools (774 cases) and 104 absent pupils were not examined. Our criterion for the diagnosis of asthma was the positive history of wheezing and dyspnea.
Results. The overall prevalence of asthma was 19.6 percent with a male to female ratio of 1.7:1 (P<0.0001). The frequencies of wheezing ever in life and sleep disturbed by wheeze were 31.7 percent and 9.5 percent, respectively. Wheeze and rhoncus on chest auscultation while the children were examined in clinic or school was recorded in 4.2 percent and 3.5 percent of the population, respectively. Pulmonary function tests revealed FEV1:5,80 percent of predicted value (prd) in 5.9 percent, FEF 25-75£70 Percent prd in 9.6 percent and FEF75£70 percent prd in 20.5 percent of tested children. The three later findings correlated to history of wheezing and dyspnea (P < 0.0001).
Discussion. The prevalence of asthma in the students of the junior high schools of Isfahan is more than average rates reported in many parts of the world, and it seems necessary to pay more attention to poorly controlled air pollution in Isfahan as an industrial city.
Keywords
ASTHMA, JUNIOR HIGH SCHOOL, PREVALENCE STUDY, CHILDHOOD, SPIROMETERY, PULMONARY FUNCTION TEST, EPIDEMIOLOGY