The effects of Tai Chi on quality of life of cancer survivors: a systematic review and meta-analysis

Purposes To assess the effects of Tai Chi on quality of life (QOL) of cancer survivors. Methods The following databases were searched: PubMed, Cochrane CENTRAL, EBSCO (including MEDLINE, CINAHL, and other databases), ScienceDirect, CNKI, Wangfang Data, and CQVIP until April 25, 2018. Randomized controlled trials (RCTs) published in English or Chinese examining the effects of Tai Chi intervention for cancer survivors were included. The primary outcome was QOL; the secondary outcomes were limb function/muscular strength, immune function indicators, cancer-related fatigue (CRF), and sleep disturbance. Methodological quality was assessed using the Cochrane Risk of Bias tool. Results of RCTs were pooled with mean difference (MD) or standardized mean difference (SMD) with 95% confidence intervals (CI). Quality of evidence for each outcome was assessed with the GRADE system. Results Twenty-two RCTs were included in this review. Tai Chi improved the physical (SMD 0.34, 95%CI 0.09, 0.59) and mental health (SMD 0.60, 95%CI 0.12, 1.08) domains of quality of life. The intervention improved the limb/muscular function of breast cancer survivors (SMD 1.19, 95%CI 0.63, 1.75) and in mixed samples of cancer survivors reduced the levels of cortisol (MD - 0.09, 95%CI - 0.16, - 0.02), alleviated CRF (SMD - 0.37, 95%CI - 0.70, - 0.04), and promoted sleep (SMD - 0.37, 95%CI - 0.72, - 0.02). Conclusion There is low-level evidence suggesting that Tai Chi improves physical and mental dimensions of QOL and sleep. There is moderate-level evidence suggesting Tai Chi reduces levels of cortisol and CRF and improves limb function. Additional studies with larger sample sizes and with higher-quality RCT designs comparing different regimens of Tai Chi are warranted.