Nonpharmacological Interventions for Dysfunctional Breathing in Adults: A Systematic Review

BACKGROUND: Dysfunctional breathing is common and leads to worse asthma outcomes. OBJECTIVES: To describe the characteristics of non-pharmacological interventions to treat dysfunctional breathing, and evidence for their efficacy. METHODS: Electronic databases (MEDLINE, Embase, CINAHL, CENTRAL and PEDro) were searched to identify studies that involved non-pharmacological interventions for people diagnosed with dysfunctional breathing. The primary aim was to determine the characteristics of intervention protocols according to the Template for Intervention Description and Replication checklist. Secondary aims included the assessment tools used, outcomes measured, and the clinical impact of the intervention. Risk of bias was assessed using the Cochrane Risk of Bias 1.0 tool or the Standard Quality Assessment Criteria depending on study design. RESULTS: Sixty-eight trials met review criteria (26 cohort studies, 20 case series, 19 randomised trials, and 3 non-randomised trials) with a total of 2119 participants. Most studies had high or unclear risk of bias across multiple domains. Five groups of non-pharmacological interventions were identified: breathing re-training ± biofeedback, psychological therapy, acupoint therapy, manual therapy, and exercise therapy. Intervention components were highly variable and inadequately reported. Breathing re-training was the most reported intervention and showed positive effects across biochemical (29/34 studies, 85%), biomechanical (10/10 studies, 100%) and psychophysiological (15/19, 79%) domains of dysfunctional breathing. There was marked heterogeneity across studies and outcomes. CONCLUSION: A variety of non-pharmacological interventions have been applied in people with dysfunctional breathing. Breathing re-training was frequently studied with low quality evidence for efficacy. Future studies should report intervention components in sufficient detail to allow replication and use consistent objective measurements to assess outcomes.