Thirty-seven studies (n=1,856 patients) were included in the review. Randomised controlled trials (RCTs), pre-post surveys, cross-sectional studies, exit surveys and individual interviews were included; some studies used more than one research design.
Qualitative and quantitative studies reported benefits of the interventions. Qualitative studies reported benefits of feeling relaxed or positive mood changes (four studies), improved memory and concentration (three studies), feelings of invigoration (two studies), increased fitness (seven studies), reduced pain, improved sleep (one study), increased social support (one study), greater efficacy than medication (one study) and global benefits (one study). Quantitative methods based on pre-post comparisons or post-intervention surveys reported improvements in all the same areas except memory and concentration.
Improvements were found on various measures of quality of life and included significant improvement on WOMAC (four studies) and Minnesota Living with Heart Failure scales (two studies). Improvements in mediators of effect, such as self-efficacy (19 studies), were reported by some studies.