Primary Objectives:

1. To evaluate the asthma control in children and adolescents with persistent asthma, and its relationship with patient characteristics, treatment and health-related variables (treatment adherence, inhalation technique, inhaler device, asthma triggers, and smoking exposure, among others).
2. To assess the health-related quality of life of children and adolescents with persistent asthma, and its relationship with patient characteristics, treatment and health-related variables (asthma control, treatment adherence and inhalation technique, inhaler device, asthma triggers, and smoking exposure, among others).
3. To assess the risk of severe asthma exacerbations in children and adolescents with persistent asthma and its relationship with patient characteristics, treatment, and health-related variables (asthma control, treatment adherence and inhalation technique, inhaler device, health-related quality of life, asthma triggers, and smoking exposure, among others).

Secondary Objectives:

1. To evaluate the effect of monitoring inhalation techniques on patients' performance according to recommended actions when using inhalers, and outcomes such as asthma control, health-related quality of life, and asthma exacerbations.
2. To assess the treatment adherence in children and adolescents with persistent asthma, and its relationship with other treatment-related factors (inhaler technique, inhaler device, adherence attitudes, and beliefs about illness, inhaler and exacerbations, among others).
3. To evaluate health inequalities in children and adolescents with asthma in Spain.

ARCA is a prospective multicenter observational study in children and adolescents with a clinical diagnosis of persistent asthma. This clinical diagnosis of asthma is defined as the presence of wheezing three times in the last year that improves with the use of bronchodilators. Participants are consecutively recruited in outpatient pediatric pulmonology hospital consultations and primary care physicians.

Patient-reported information is obtained by computer-assisted telephone interviews (CATI) and a mobile application (ARCA App). Telephone interviews are performed by trained interviewers to children 8-16 years old and parents/caregivers of children 6-7 years of age, immediately after recruitment and every 6 months. It includes the evaluation of asthma control, prescribed asthma treatment, adherence, and severe asthma exacerbations. Information about inhalation techniques, socioeconomic status, smoking exposure, triggers, use of peak flow, symptom diary, perceived asthma care, adherence attitudes, and beliefs about illness, inhaler and exacerbations is also collected.

The 'ARCA app' combines 3 age versions: parents/guardians (proxy response) for children 6-7 years old, children aged 8-11 years (self-response), and adolescents aged 12-16 years (self-response). The application consists in an interactive chat, simulating a conversation by Short Message Service (SMS) or Instant Messaging Application (WhatsApp) with someone in real time. It includes the monthly administration of 2 questions (global rating of change and severe asthma exacerbations). At the beginning, after downloading the app, and every two months different standardized questionnaires are administered by turns: the EuroQol (EQ-5D), the Pediatric Asthma Impact Scale (PAIS), inhalation techniques scale, and environment support. These latter scales are administered randomly to two groups of equal size, defined within the subsample recruited by each pediatrician.

All the information that each participant answers through the app can be viewed by the pediatrician through a specific platform. The results of the different questionnaires are shown in charts reflecting the patient's answers over time, using the traffic lights code: green for good outcomes, amber for intermediate, and red for poor. Clinical data is registered at recruitment and annually during the follow-up.

Sample size: To detect differences between two groups in the Asthma Control Questionnaire score of 0.3 SD, 175 patients per group would be required to have a statistical power of 80%, at a significance level of 5%.