Breathing Pattern Assessment Tool as a new screening tool to identify dysfunctional breathing

Background: Dysfunctional breathing (DB) is one of the most common co-morbidities in patients with difficult asthma. However, the prevalence and impact of DB in general populations with difficult asthma has not previously been reported and beyond the clinical description there is no gold standard for the diagnosis of DB. Objective: To investigate: 1) the prevalence of DB among patients with difficult asthma 2) The Breathing Pattern Assessment Tool (BPAT) as a screening tool to identify DB. Methods: Patients ≥18 years old with difficult asthma according to the ERS/ATS 2014 guidelines seen in four respiratory outpatient clinics over a year underwent systematic assessment in which potential causes of poor asthma control were systematically investigated including screening for DB with the Nijmegen questionnaire and objective signs of DB with BPAT, which evaluates aspects of breathing such as flow and rate. Results: A total of 117 patients with difficult asthma were included. Among these, 29.9 % (35/117) had DB according to the Nijmegen score. Patients with DB had a poorer asthma control (ACQ: Mean (SD) 2.86 ± 1.05 vs. 1.46 ± 0.93) and lower quality of life (AQLQ score: Mean (SD) 4.2 ± 1.04 vs. 5.49 ± 0.85) vs. patients without DB. Similarly, patients with objective signs of DB according to the BPAT score had worse asthma control: BPAT > 4 vs Conclusion: DB is a common co-morbidity among difficult asthma patients. The BPAT tool identified DB associated with poor asthma control, suggesting that objective breathing pattern assessment may be useful in addition to symptom based assessment. The BPAT and NQ do not seem to identify the same patients.