Asthma medication use in infancy: Determinants related to prescription

Objective: The aim of this study was to describe which factors besides respiratory symptoms are related to asthma therapy prescription in infancy. Methods: Our study population consisted of 1202 children who participated in the WHISTLER study. Determinants of therapy initiation were assessed in the total population, children with parent reported symptoms and children with physician diagnosed symptoms. Determinants of refill were studied in children who filled an asthma mediation prescription in their first year of life. Logistic regression analysis was used to study determinants of prescription. Results: Fifteen percent of all infants started anti-asthma therapy in the first year of life. Respiratory symptoms were positively associated with prescriptions as well as day-care attendance. For the total population, therapy initiation was associated with male gender (OR = 2.0, 95% CI 1.4-2.7), maternal allergy (OR = 1.4, 95% CI 1.0-1.9) and maternal asthma (OR = 1.8, 95% CI 1.0-3.0). For children with parent reported symptoms therapy initiation was associated with male gender (OR = 1.6, 95% CI 1.0-2.4). For children with physician diagnosed symptoms, therapy initiation was negatively associated with breastfeeding (OR = 0.5, 95% CI 0.2-0.9). Refill of prescriptions was associated with Caucasian ethnicity (mother OR = 3.6, 95% CI 1.6-8.2 and father OR = 2.6, 95% CI 1.1-6.3). Conclusion: A rather high percentage of children received anti-asthma therapy in the first year of life. Asthma therapy initiation is difficult in infancy; part of the children do not need nor respond to asthma medication. Respiratory symptoms were an important determinant of asthma medication prescription. However, also non-symptom related factors played a role in prescribing and more strongly when the risk for asthma increases. Parental and environmental factors are very important for general practitioner prescription behaviour.