Asthma therapy during the first 8 years of life: a PIAMA cohort study

OBJECTIVE: Many studies evaluated asthma medication use in children in a cross-sectional manner, yet little is known about longitudinal use patterns. This study describes the formation of a longitudinal data set on asthma medication use and shows first results regarding the prevalence and incidence of medication use. METHODS: The PIAMA (Prevention and Incidence of Asthma and Mite Allergy) study is a prospective birth cohort study among 3963 Dutch children. Recruitment took place in 1996-1997. The data of the PIAMA birth cohort study were complemented with pharmacy data. Prescription information of family members was used to determine whether medication histories were complete from birth until age 8. The prevalence and incidence of asthma medication use was studied in children for whom complete medication histories were available. RESULTS: A first prescription for asthma medication was filled before age 8 by 280 (36%) children, with 88% starting therapy before age 5. Of all children who started therapy, 91.1% received short-acting beta(2)-agonists and 61.1% inhaled corticosteroids. CONCLUSION: The applied method of data collection rendered a data set including 777 children with complete medication histories for their first 8 years of life. This data set provides the opportunity to study longitudinal medication use patterns. First analyses show that asthma medication is initiated in a rather high percentage of children in this cohort and mainly at an age at which an asthma diagnosis cannot yet be firmly established.