Are positive alternative medical therapy trials credible?: Evidence from four high-impact medical journals.
Forty-five complementary and alternative medicine (CAM) efficacy randomized controlled trials (RCTs) from high-impact medical journals (NEJM, JAMA, Annals of Internal Medicine, and Archives of Internal Medicine) were reviewed based on their meeting three validity criteria (the existence of a placebo control, moderate attrition rates, and 50 or more participants per group). Of the 26 efficacy trials meeting all three criteria, only 2 (7.7%) were judged to be positive (i.e., the alternative therapy was significantly superior to its placebo control), while over half (55.5%) of the 19 trials that failed to meet one or more of these criteria reported positive results (p < .001). Of the two positive high-validity trials, one was funded and authored by the herbal company marketing the product tested and one used a placebo-control group of questionable credibility. This analysis is consistent with the hypothesis that CAM therapies are no more effective than placebos when adequate experimental control is present.
Barker Bausell
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University of Maryland School of Nursing, Baltimore, Maryland 21201, USA. bausell@son.umaryland.edu
D000529:Complementary Therapies / Q000379:methods / Q000592:standards*; D003627:Data Interpretation, Statistical; D006801:Humans; D018156:Journalism, Medical / Q000592:standards; D015990:Placebo Effect; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D015203:Reproducibility of Results