Novel assessment tool to detect breathing pattern disorder in patients with refractory asthma.

ABSTRACT

BACKGROUND AND OBJECTIVE: Breathing pattern disorder (BPD) can co-exist with and mimic asthma, acting to amplify symptoms and confound assessment of disease control, resulting in inappropriate treatment escalation. The aim of this research was to report the utility of a novel breathing pattern assessment tool (BPAT) to detect BPD in treatment-refractory asthma. METHODS: As a component of a multidisciplinary assessment, adult patients referred with treatment-refractory asthma underwent respiratory physiotherapy assessment to diagnose BPD. Based on this assessment, patients were classified as having asthma, asthma + BPD or BPD alone. BPAT data were collected in addition to questionnaire data (Asthma Quality of Life Questionnaire (AQLQ) and Nijmegen Questionnaire (NQ)), pulmonary function and an assessment of exercise capacity. RESULTS: Data were retrospectively analysed for 150 (female; 69%) patients, mean (SD) age of 43 (14) years; characterized as asthma-only (n = 54, 36%), asthma + BPD (n = 63, 42%) and BPD-only (n = 33, 22%). Of the total population, 113 (76%) had an NQ score ≥23, but of these only 68% had physiotherapy evidence of BPD. Exercise capacity and AQLQ were lower in the asthma + BPD group than in the asthma-only group (P < 0.05), whilst lung function was similar between groups. Sensitivity analysis indicated that a BPAT score of ≥4 corresponded to a sensitivity of 0.92 and a specificity of 0.75 for diagnosis of BPD in this cohort. CONCLUSION: Breathing pattern irregularities are highly prevalent in individuals referred with treatment-refractory asthma and can be characterized using the BPAT. Further work is needed to determine inter-observer and within-subject variability and ensure the BPAT is a robust clinical tool. Watch the video abstract.