Prevalence and patient characteristics of dysfunctional breathing in children and adolescents with asthma

Abstract

Background: Dysfunctional breathing (DB) has been shown to negatively affect asthma control in adults, but in children and adolescents, the knowledge is scarce. DB is among others characterized by dyspnea and hyperventilation. The Nijmegen Questionnairre (NQ) is often used as a marker for DB.

Aims and objectives: to estimate the prevalence of DB in children and adolescents with asthma in a hospital outpatient clinic and to describe patterns of this group regarding asthma treatment and control.

Methods: Patients between 10-17 years were invited to complete the NQ, the Asthma Control Questionnairre (ACQ) and report use of beta2 agonist (β2), when attending our outpatient clinic for a scheduled asthma follow up visit. Spirometry data and prescribed asthma medications were noted.

Results: 363 patients (180 boys) completed the survey. 67 patients (18 %) scored ≥23 points in the NQ predicting DB. The DB group was older (median (range)) 15.6 (10.5-17.9) vs 13.7 (10.0-17.9) years) (p<0.01) and girls were overrepresented (84 %) (p< 0.01). FEV1% exp. was higher in the DB group (mean (SD)) (89.4 (9.0) vs 85.7 (11.8)) (p< 0.02). ACQ score (median (range)) (2.0 (0-4) vs 0.6 (0-3.4)) (p<0.01) and use of β2 (median (range)) (2 (0-56) vs 0 (0-20) puffs/week) (p< 0.01) were higher, predicting poorer perceived asthma control. Inhaled corticosteroid dose (mean (SD) (416 (160) vs 420 (150) mcg), and use of a second controller were equal between the groups.

Conclusion: Dysfunctional breathing was a frequent complication of asthma, especially in adolescent girls. DB was correlated with poorer asthma control and higher use of β2 and may be an important cofactor in difficult-to-treat asthma.