Children and adolescents with asthma, particularly adolescent girls with asthma, frequently have comorbid dysfunctional breathing (DB), which is correlated with poorer asthma control and higher use of beta2 agonists (β2), according to survey findings published in Pediatric Allergy and Immunology.
Investigators sought to estimate DB prevalence in children and adolescents with asthma and to characterize patterns in asthma diagnosis, treatment and compliance, and demographics to determine the impact of DB on asthma control.
A cross-sectional survey was used to estimate the prevalence of DB in pediatric patients with asthma presenting at the Pediatric and Adolescent Outpatient Clinic, University Hospital of Lillebaelt, Kolding, Denmark, for 15 months starting in February 2021. The survey was completed by 363 pediatric patients (including 183 girls) who were 10 to 17 years of age, had physician-diagnosed asthma, and used inhaled corticosteroids during the 3 months prior to survey administration.
The survey included the Nijmegen Questionnaire (NQ; used as a marker for DB), the Asthma Control Questionnaire, and questions pertaining to use of β2. Data on spirometry and prescribed asthma medications were derived from patient records. To gage the effect of DB (as measured by an NQ score of at least 23) on asthma control, investigators used a multiple regression model that used ACQ as a dependent variable and independent variables that included sex, age, body mass index, β2, forced expiratory volume in 1 second (FEV1), FEV1/forced vital capacity, allergy status, NQ responses, and add-on medication.
We suggest that DB may be a confounder of asthma symptoms, leading to a misinterpretation of asthma control as worse than is actually the case. Based on our study, we suggest routine screening for DB in difficult-to-treat pediatric and adolescent asthma in order to avoid overtreatment.
The analysis found that 18% of participants had DB (based on their NQ score). Compared with the non-DB group, the DB group was older (median 15.6 years, range 10.5-17.9 vs 13.7 years, range 10.0-17.9; P <.01) and had a preponderance of girls in the DB group (84%; P <.01). Investigators also found that in the DB group vs the non-DB group, median use of β2 was higher (2 puffs/week [range, 0-56] vs 0 puffs/week [range 0-20]) and median ACQ scores were higher (2.0 [range, 0-4] vs 0.6 [range, 0-3.4]; P <.01), predicting poorer perceived asthma control, and that mean (SD) forced expiratory volume in 1 second (FEV1) was higher (89.4 [9.0] vs 85.7 [11.8]; P <.02).
Investigators noted mean inhaled corticosteroid doses were equal between groups (416  mcg vs 420  mcg) as was use of a second controller and nasal steroids. Compliance with prescribed inhaled corticosteroids was 80% in the DB group and 85% in the non-DB group.
Female sex (P <.01), older age (P <.01), higher FEV1 (P <.05), and higher ACQ score (P <.001) were predictors of DB. Higher use of bronchial reliever medication and higher NQ scores predicted poorer asthma control as estimated by ACQ (P <.001 for both).
Significant survey limitations include a lack of information regarding comorbidities (psychiatric or functional symptoms); reliance on the NQ, a tool that is not validated for children and adolescents; and response bias due to the use of self-reported data.
Investigators concluded that especially in adolescent girls, DB was a frequent comorbidity negatively impacting perceived asthma control. “We suggest that DB may be a confounder of asthma symptoms, leading to a misinterpretation of asthma control as worse than is actually the case. Based on our study, we suggest routine screening for DB in difficult-to-treat pediatric and adolescent asthma in order to avoid overtreatment,” the study authors added.