Evidence from the Cochrane Collaboration for Traditional Chinese Medicine therapies.

Manheimer, Eric; Wieland, Susan; Kimbrough, Elizabeth; Cheng, Ker; Berman, Brian M

BACKGROUND The Cochrane Collaboration, an international not-for-profit organization that prepares and maintains systematic reviews of randomized trials of health care therapies, has produced reviews summarizing much of the evidence on Traditional Chinese Medicine (TCM). Our objective was to review the evidence base according to Cochrane systematic reviews. METHODS In order to detect reviews focusing on TCM, we searched the titles and abstracts of all reviews in Issue 4, 2008 of the Cochrane Database of Systematic Reviews. For each review, we extracted data on the number of trials included and the total number of participants. We provided an indication of the strength of the review findings by assessing the reviewers' abstract conclusions statement. We supplemented our assessment of the abstract conclusions statements with a listing of the comparisons and outcomes showing statistically significant meta-analyses results. RESULTS We identified 70 Cochrane systematic reviews of TCM, primarily acupuncture (n = 26) and Chinese herbal medicine (n = 42), and 1 each of moxibustion and t'ai chi. Nineteen (19) of 26 acupuncture reviews and 22/42 herbal medicine reviews concluded that there was not enough good quality trial evidence to make any conclusion about the efficacy of the evaluated treatment, while the remaining 7 acupuncture and 20 herbal medicine reviews and each of the moxibustion and t'ai chi reviews indicated a suggestion of benefit, which was qualified by a caveat about the poor quality and quantity of studies. Most reviews included many distinct interventions, controls, outcomes, and populations, and a large number of different comparisons were made, each with a distinct forest plot. CONCLUSIONS Most Cochrane systematic reviews of TCM are inconclusive, due specifically to the poor methodology and heterogeneity of the studies reviewed. Some systematic reviews provide preliminary evidence of Chinese medicine's benefits to certain patient populations, underscoring the importance and appropriateness of further research. These preliminary findings should be considered tentative and need to be confirmed with rigorous randomized controlled trials.