Evaluation of randomized controlled trials on complementary and alternative medicine

Objectives: Use of complementary and alternative medicine (CAM) is growing in all Western countries. The goal of this study was to evaluate quality of randomized controlled trials (RCTs) of CAM interventions for specific diag noses to inform clinical decision making. Methods: MEDLINE and related databases were searched for CAM RCTs. Visual r eview was done of bibliographies, meta-analyses, and CAM journals. Inclusio n criteria for review and scoring were blinded RCT, specified diagnosis and intervention, complete study published between January 1, 1966 and July 31 , 1998 in an English-language, peer-reviewed journal. Two reviewers indepen dently scored each study. Results: More than 5,000 trials were found, but only 258 met all study incl usion criteria. The main cause for rejection (> 90%) was that the study was not an RCT or had no blinding. Mean score across 95 diagnosis/intervention categories was 44.7 (S.D. +/- 14.3) on a 100-point scale. Ordinary least-s quares regression found date of publication, biostatistician as author or c onsultant, published in one of five widely read English-language medical jo urnals and diagnosis/intervention category of hypertension/relaxation as si gnificant predictors of higher scores. Conclusions: The overall quality of evidence for CAM RCTs is poor but impro ving slowly over time, about the same as that of biomedicine. Thus, most se rvices are provided without good evidence of benefit.