Does yoga improve quality of life and symptoms in patients with asthma?
Regular yoga improves quality of life as measured on the Asthma Quality of Life Questionnaire (mean difference = 0.57 units on a seven-point scale; 95% confidence interval [CI], 0.37 to 0.77); improves asthma symptoms (standardized mean difference = 0.37; 95% CI, 0.09 to 0.65); and reduces medication use (relative risk [RR] = 5.35; 95% CI, 1.29 to 22.11). However, the high risk of bias and heterogeneity in the included studies limit firm conclusions about the role of yoga in the care of patients with asthma.1 (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)
Asthma affects 24.6 million Americans.2 In the United States, asthma care costs more than $12.7 billion annually and is associated with absenteeism costs from $6 million to $383 million per state.3 Yoga practice is also prevalent in the United States, with 21 million adult practitioners. Some evidence suggests that yoga may be helpful in improving asthma symptoms and asthma-related quality of life. The authors of this review investigated the effects of yoga on patients with asthma.
This review included 15 randomized controlled trials with 1,048 participants.1 Yoga improved quality of life by a mean 0.57 units on each item of the seven-point scale on the Asthma Quality of Life Questionnaire (95% CI, 0.37 to 0.77), in which a 0.5-unit change is considered significant. Yoga also improved asthma symptoms (standardized mean difference = 0.37; 95% CI, 0.09 to 0.65), although there is no defined minimal clinically important difference for the scale used to assess this. Yoga also reduced medication use (RR = 5.35; 95% CI, 1.29 to 22.11); however, the medications assessed varied among studies, and two studies that were not included in the review demonstrated no differences in medication use.
Yoga had a mixed effect on spirometry parameters. It provided no benefit for forced expiratory volume in one second (FEV1), seemed to improve the peak expiratory flow rate and forced vital capacity (FVC), but had no effect on the FEV1/FVC ratio. Four of the studies in the review looked at adverse effects but did not find enough information to draw conclusions. The authors noted that, despite significant differences in quality-of-life, symptom, and some spirometry parameters, the high risk of bias and heterogeneity in the included studies limited firm conclusions about the role of yoga in the care of patients with asthma.
Clinical guidelines do not mention yoga in the treatment of asthma. Although the European Respiratory Society/American Thoracic Society clinical practice guidelines discuss obesity, tobacco smoke, and air pollution as lifestyle and environmental factors associated with asthma, they do not include yoga as a treatment option.4 The Institute for Clinical Systems Improvement similarly discusses using medications, removing environmental triggers, and raising patient awareness about when asthma symptoms are worsening, but it does not include yoga among its treatment recommendations.5 Despite limited evidence supporting its use, yoga has minimal adverse effects and general health benefits, and it can be considered as an adjunct to traditional pharmacotherapy and environmental risk modification in patients with asthma.
The practice recommendations in this activity are available at http://www.cochrane.org/CD010346.
The views expressed are the author's and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences, the U.S. Army, the Department of Defense, or the U.S. government.