Effect of a Daily Text Reminder on Asthma Medication Use, Symptom Control, and Lung Function in Children

Inhaler adherence was measured using the Inhaler Adherence Scale for Children (IASC), which evaluates adherence across three domains: Cognitive, Psychosocial, and Control & Autonomy. The scale consists of 12 questions, with responses ranging from 0 (indicating poor adherence) to 4 (indicating full adherence) for each question. A higher total score indicates better adherence.

Symptom control was assessed using the Asthma Control Test (ACT) for participants aged 12 years and older, and the Childhood Asthma Control Test (c-ACT) for children under 12 years old. The ACT consists of 5 questions regarding asthma symptoms, and the c-ACT includes 4 questions for the child and 3 for the caregiver. A higher score indicates better control over asthma symptoms.

Pulmonary function was assessed using spirometry at 90 days (T2). This measure evaluates the participants' lung function by assessing key parameters such as Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC). A bronchodilator response (BDR) was defined as an increase of more than 10% in FEV₁ or FVC following the administration of 400 µg of inhaled salbutamol; responses below this threshold indicated absence of BDR. Pulmonary function was categorized into four groups: (1) normal baseline spirometry without BDR (considered the only normal pattern), (2) normal baseline spirometry with BDR, (3) obstructive pattern without BDR, and (4) obstructive pattern with BDR. Additionally, lung function impairment severity was classified using z-score values: > -1.645 (normal), -1.65 to -2.5 (mild), -2.51 to -4 (moderate), and < -4.1 (severe).