Asthma is a lung disease, that comprises underlying inflammation and tightening of the small tubes in the airways (called airway obstruction), which occurs in response to asthma triggers such as animal danders or pollen (also called bronchial hyperresponsiveness). The high prevalence of asthma worldwide is a major public health problem because of the high healthcare costs associated with hospitalisation and medication. Breathing exercises are a non-pharmacological intervention that has been used routinely in the treatment of patients with asthma. Breathing exercises aim to control the hyperventilation symptoms of asthma and can be performed as the Papworth Method, the Buteyko breathing technique, yoga or any other similar intervention that manipulates the breathing pattern.
We wanted to look at available evidence for the effectiveness of breathing exercises in adults with asthma.
We found 13 studies involving 906 adults with mild to moderate asthma. Eleven studies compared breathing exercises with inactive controls and two with asthma education control groups. Overall, improvements in quality of life, asthma symptoms and numbers of exacerbations were reported. Six of the eleven studies that assessed lung function showed a significant difference favouring breathing exercises. No adverse effects related to the intervention were described, which indicates that this is a safe and well-tolerated intervention in people with asthma.
Quality of the evidence
The trials were different in terms of type of breathing exercises performed, number of participants enrolled, number and duration of sessions completed, outcomes reported and statistical presentation of data. As a result, we were not able to compare the results from these trials using a meta-analysis for all outcomes. Meta-analysis was possible for only two outcomes (asthma symptoms and change in Asthma Quality of Life Questionnaire—AQLQ), each of which was reported in only two studies. Both meta-analyses showed a significant difference favouring breathing exercises. The methods used to conduct these studies were not as well reported as we would have liked, and so the quality of the trials was unclear. Overall the quality of the evidence included in the review was very low.
Even though individual trials reported positive effects of breathing exercises, no conclusive evidence in this review supports or refutes the efficacy of such intervention in the treatment of adult patients with asthma.
Even though individual trials reported positive effects of breathing exercises, no reliable conclusions could be drawn concerning the use of breathing exercises for asthma in clinical practice. This was a result of methodological differences among the included studies and poor reporting of methodological aspects in most of the included studies. However, trends for improvement are encouraging, and further studies including full descriptions of treatment methods and outcome measurements are required.
Breathing exercises have been widely used worldwide as a complementary therapy to the pharmacological treatment of people with asthma.
To evaluate the evidence for the efficacy of breathing exercises in the management of patients with asthma.
The search for trials led review authors to review the literature available in The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and AMED and to perform handsearching of respiratory journals and meeting abstracts. Trial registers and reference lists of included articles were also consulted.
The literature search has been updated to January 2013.
We included randomised controlled trials of breathing exercises in adults with asthma compared with a control group receiving asthma education or, alternatively, with no active control group.
Two review authors independently assessed trial quality and extracted data. RevMan software was used for data analysis based on the fixed-effect model. Continuous outcomes were expressed as mean differences (MDs) with confidence intervals (CIs) of 95%. Heterogeneity was assessed by inspecting the forest plots. The Chi2 test was applied, with a P value of 0.10 indicating statistical significance. The I2 statistic was implemented, with a value greater than 50% representing a substantial level of heterogeneity.
A total of 13 studies involving 906 participants are included in the review. The trials were different from one another in terms of type of breathing exercise performed, number of participants enrolled, number and duration of sessions completed, outcomes reported and statistical presentation of data. Asthma severity in participants from the included studies ranged from mild to moderate, and the samples consisted solely of outpatients. The following outcomes were measured: quality of life, asthma symptoms, number of acute exacerbations and lung function. Eleven studies compared breathing exercise with inactive control, and two with asthma education control groups. All eight studies that assessed quality of life reported an improvement in this outcome. An improvement in the number of acute exacerbations was observed by the only study that assessed this outcome. Six of seven included studies showed significant differences favouring breathing exercises for asthma symptoms. Effects on lung function were more variable, with no difference reported in five of the eleven studies that assessed this outcome, while the other six showed a significant difference for this outcome, which favoured breathing exercises. As a result of substantial heterogeneity among the studies, meta-analysis was possible only for asthma symptoms and changes in the Asthma Quality of Life Questionnaire (AQLQ). Each meta-analysis included only two studies and showed a significant difference favouring breathing exercises (MD -3.22, 95% CI -6.31 to -0.13 for asthma symptoms; MD 0.79, 95% CI 0.50 to 1.08 for change in AQLQ). Assessment of risk of bias was impaired by incomplete reporting of methodological aspects of most of the included trials.