Determining the safety and effectiveness of Tai Chi: a critical overview of 210 systematic reviews of controlled clinical trials Author: Guo-Yan Yang#1, Jennifer Hunter#2, Fan-Long Bu3, Wen-Li Hao4, Han Zhang5, Peter M Wayne6, Jian-Ping Liu7,8 Affiliation: <sup>1</sup> NICM Health Research Institute, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia. e.yang@westernsydney.edu.au. <sup>2</sup> Health Research Group, Sydney, NSW, 2000, Australia. <sup>3</sup> National Center for Children&#x27;s Health, Beijing Children&#x27;s Hospital, Capital Medical University, Beijing, 100045, China. <sup>4</sup> Public Health School, Inner Mongolia Medical University, Hohht, 010000, Inner Mongolia, China. <sup>5</sup> School of Acupuncture and Massage, Beijing University of Chinese Medicine, Beijing, 100029, China. <sup>6</sup> Osher Center for Integrative Medicine, Brigham and Women&#x27;s Hospital and Harvard Medical School, Boston, MA, 02215, USA. <sup>7</sup> Center for Evidence-Based Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China. <sup>8</sup> The Faculty of Health Science, Department of Community Medicine, UiT The Arctic University of Norway, The National Research Center in Complementary and Alternative Medicine - NAFKAM, Hansine Hansens veg 19, 9037, Tromsø, Norway. Conference/Journal: Syst Rev Date published: 2022 Dec 3 Other: Volume ID: 11 , Issue ID: 1 , Pages: 260 , Special Notes: doi: 10.1186/s13643-022-02100-5. , Word Count: 332 Background: This overview summarizes the best available systematic review (SR) evidence on the health effects of Tai Chi. Methods: Nine databases (PubMed, Cochrane Library, EMBASE, Medline, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), Sino-Med, and Wanfang Database) were searched for SRs of controlled clinical trials of Tai Chi interventions published between Jan 2010 and Dec 2020 in any language. Effect estimates were extracted from the most recent, comprehensive, highest-quality SR for each population, condition, and outcome. SR quality was appraised with AMSTAR 2 and overall certainty of effect estimates with the GRADE method. Results: Of the 210 included SRs, 193 only included randomized controlled trials, one only included non-randomized studies of interventions, and 16 included both. Common conditions were neurological (18.6%), falls/balance (14.7%), cardiovascular (14.7%), musculoskeletal (11.0%), cancer (7.1%), and diabetes mellitus (6.7%). Except for stroke, no evidence for disease prevention was found; however, multiple proxy-outcomes/risks factors were evaluated. One hundred and fourteen effect estimates were extracted from 37 SRs (2 high, 6 moderate, 18 low, and 11 critically low quality), representing 59,306 adults. Compared to active and/or inactive controls, 66 of the 114 effect estimates reported clinically important benefits from Tai Chi, 53 reported an equivalent or marginal benefit, and 6 an equivalent risk of adverse events. Eight of the 114 effect estimates (7.0%) were rated as high, 43 (37.7%) moderate, 36 (31.6%) low, and 27 (23.7%) very low certainty evidence due to concerns with risk of bias (92/114, 80.7%), imprecision (43/114, 37.7%), inconsistency (37/114, 32.5%), and publication bias (3/114, 2.6%). SR quality was often limited by the search strategies, language bias, inadequate consideration of clinical, methodological, and statistical heterogeneity, poor reporting standards, and/or no registered SR protocol. Conclusions: The findings suggest Tai Chi has multidimensional effects, including physical, psychological and quality of life benefits for a wide range of conditions, as well as multimorbidity. Clinically important benefits were most consistently reported for Parkinson's disease, falls risk, knee osteoarthritis, low back pain, cerebrovascular, and cardiovascular diseases including hypertension. For most conditions, higher-quality SRs with rigorous primary studies are required. Systematic review registration: PROSPERO CRD42021225708. Keywords: Overview; Prevention; Rehabilitation; Systematic review; Tai Chi; Treatment. PMID: 36463306 DOI: 10.1186/s13643-022-02100-5