BACKGROUND AND OBJECTIVE: To estimate the incidence of asthma in schoolchildren from 6-7 years old to 14-15 years old and associated risk factors. POPULATION AND METHOD: A cohort study, with the ISAAC phases I and III in 1994 and 2002, respectively, was carried out in Castellón, and the nearby towns Vila-real, Almassora, Benicàssim, El Grau de Castelló, Borriol, and L'Alcora. In 1992, 3,607 schoolchildren aged 6-7 years old took part, of whom 1,805 were again studied in 2002, at the age of 14-15. New cases of asthma were defined following the ISAAC questionnaire. Poisson regression was used in the analysis of asthma risk factors. RESULTS: Participation was 50.0%. The cumulative incidence of asthma was 6.4% during the 8 years of study, 108 new cases of 1,698 schoolchildren free of asthma at beginning. Incidence was greater in boys than girls, and in 14-year old teenagers compared to 15-year olds, although differences were not significant. Risk factors associated with the incidence of asthma were: family history of asthma, history of allergic rhinitis, history of bronchitis and upper-middle compared to lower social class. CONCLUSIONS: A low incidence of asthma was found in schoolchildren from Castellón, Spain, in comparison with other cohort studies. Estimated risk factors were generally in accordance with incidence studies.
BACKGROUND AND OBJECTIVE: To estimate the incidence of asthma in schoolchildren from 6-7 years old to 14-15 years old and associated risk factors. POPULATION AND METHOD: A cohort study, with the ISAAC phases I and III in 1994 and 2002, respectively, was carried out in Castellón, and the nearby towns Vila-real, Almassora, Benicàssim, El Grau de Castelló, Borriol, and L'Alcora. In 1992, 3,607 schoolchildren aged 6-7 years old took part, of whom 1,805 were again studied in 2002, at the age of 14-15. New cases of asthma were defined following the ISAAC questionnaire. Poisson regression was used in the analysis of asthma risk factors. RESULTS: Participation was 50.0%. The cumulative incidence of asthma was 6.4% during the 8 years of study, 108 new cases of 1,698 schoolchildren free of asthma at beginning. Incidence was greater in boys than girls, and in 14-year old teenagers compared to 15-year olds, although differences were not significant. Risk factors associated with the incidence of asthma were: family history of asthma, history of allergic rhinitis, history of bronchitis and upper-middle compared to lower social class. CONCLUSIONS: A low incidence of asthma was found in schoolchildren from Castellón, Spain, in comparison with other cohort studies. Estimated risk factors were generally in accordance with incidence studies.