Nonpharmacological Interventions for Dysfunctional Breathing in Adults: A Systematic Review.

Background: Dysfunctional breathing is common and leads to worse asthma outcomes.

Objective: To describe the characteristics of nonpharmacological interventions to treat dysfunctional breathing, and evidence for their efficacy.

Methods: We searched electronic databases (MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, and Physiotherapy Evidence Database) to identify studies that involved nonpharmacological interventions for people with the diagnosis of 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. We assessed the risk of bias using the Cochrane Risk of Bias 1.0 tool or the Standard Quality Assessment Criteria, depending on the study design.

Results: A total of 68 trials met review criteria (26 cohort studies, 20 case series, 19 randomized trials, and three nonrandomized trials), with 2,119 participants. Most studies had a high or unclear risk of bias across multiple domains. Five groups of nonpharmacological interventions were identified: breathing retraining with or without biofeedback, psychological therapy, acupoint therapy, manual therapy, and exercise therapy. Intervention components were highly variable and inadequately reported. Breathing retraining was the most reported intervention and showed positive effects across biochemical (29 of 34 studies; 85%), biomechanical (10 of 10 studies; 100%), and psychophysiological (15 of 19; 79%) domains of dysfunctional breathing. There was marked heterogeneity across studies and outcomes.

Conclusions: A variety of nonpharmacological interventions have been applied in people with dysfunctional breathing. Breathing retraining 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.