Symptom control
Symptom control was assessed using Test for Respiratory and Asthma
Control in Kids (TRACK) questionnaire. This is a standardised tool
validated to identify symptom control over the preceding 4 weeks in
children with preschool wheeze[12]. It is a 5‐item, 100‐point
caregiver‐completed questionnaire, with poor asthma control defined as a
score of <80/100 (see figure 1 online supplement). A change in
score of >10 is the minimum clinically meaningful
change[13].