Uncontrolled Asthma in School-Aged Children—a Nationwide Specialist Care Study

Previous questionnaire-based studies have determined the prevalence of uncontrolled childhood asthma (UCA) to be greater than 50%. The purpose of this study was to identify and describe the uncontrolled pediatric asthma population across all Global Initiative for Asthma (GINA) treatment steps.The study included 5,497 Swedish children aged 6 to 17 years treated for asthma in the outpatient setting through the Swedish National Airway Register.The study was a cross-sectional cohort study that defined UCA as those patients with an forced expiratory volume (FEV) 1 < 80%, and/or ≥2 exacerbations per year, and/or Asthma Control Test (ACT) score ≤ 19. Many variables, including demographic data, BMI, lung function as FEV1% of predicted, exacerbations, allergic diagnosis, asthma education, and written treatment plan availability were also extracted from the Swedish National Airway Register. Asthma treatment was classified by GINA 2018 guideline steps: step 1 (SABA or LABA PRN), step 2 (ICS or LTRA), step 3 (ICS + LABA, ICS + LTRA, or LTRA + LABA), step 4 (ICS + LABA + LAMA and/or LTRA), and step 5 (biologics). Additionally, temperature laminar airflow, a step 5 treatment available in Sweden, was included. χ2, ANOVA, and independent sample t tests were used to compare groups. Bivariate and multivariate logistic regression analysis were used to evaluate ORs and 95% CIs.Among the study population, almost 31% had UCA, and the most frequently met criteria for diagnosis was a low ACT score (64%), followed by airflow limitation (31%) and recurrent exacerbations (20%). UCA was most prevalent in patients on steps 4 and 5 (34.7%). These patients were also more likely to be given written action plans and asthma education. There were 58% of children on step 1 and 2 of treatment. There was a statistically significant difference between age, sex, and BMI in uncontrolled versus controlled asthma patients in steps 1 and 2, with uncontrolled patients more often being female, older, and obese. Patients with UCA on treatment steps 1 and 2 were younger, had higher ACT scores and were less likely to be obese or have an allergic diagnosis but were more likely to have exacerbations than those on steps 4 and 5.Associations with uncontrolled childhood asthma include obesity, female sex, older age, and higher GINA treatment step. Patients with UCA and recurrent exacerbations are being undertreated, particularly those on GINA step 1 and 2.Asthma is the most common chronic childhood disease, with improved control being the primary outcome goal of disease management. The immediate risk of undertreatment is the increased symptomatic disease burden on the patient, but longer-term risks include overall elevated healthcare costs and resource utilization, as well as subsequent pulmonary dysfunction. The large size of this study population and standardized national register source allows for effective extrapolation and generalizability of its results, in addition to a diminished selection bias.