Persistent Asthma at School Age: Associated Factors in Preschool Children with Asthma.

Most patients with childhood asthma present their first symptoms at preschool age. Identifying modifiable risks and protective factors at an early age may help develop asthma prevention and control strategies. This study aimed to identify factors at preschool age that are associated with persistent asthma at school age. This retrospective observational study included preschool children with asthma from 2015 to 2020 at a university hospital in Southern Thailand. In total, 189 eligible participants (70.9% boys; median age, 7.6 [6.7, 8.5] years) were included. Wheeze characteristics included early transient wheeze, persistent wheeze, and late-onset wheeze that accounted for 55%, 27.5%, and 19.5% of the patients, respectively. Approximately 20% of the participants had persistent asthma. Breastfeeding was a protective factor (odds ratio [OR] 0.4 [0.2, 0.9], = 0.04). The modifiable risk factors were siblings living in the same household (OR 2.6 [1.1, 6.2], = 0.02) and residence in an industrial area (OR 3.8 [1.4, 10.5], = 0.009). Additionally, presence of allergic rhinitis was associated with an increased risk of persistent asthma at school age (OR 3.6 [1.6, 8.2], = 0.002). Early therapeutic interventions targeting modifiable factors provide a window of opportunity to prevent persistent asthma at school age.