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 diagnoses to inform clinical decision making.
Methods: MEDLINE and related databases were searched for CAM RCTs.
Visual review was done of bibliographies, meta-analyses, and CAM journals.
Inclusion 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
independently scored each study.
Results: More than 5,000 trials were found, but only 258 met all
study inclusion 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-squares regression found date of publication,
biostatistician as author or consultant, published in one of five widely read
English-language medical journals and diagnosis/intervention category of
hypertension/relaxation as significant predictors of higher scores.
Conclusions: The overall quality of evidence for CAM RCTs is poor
but improving slowly over time, about the same as that of biomedicine. Thus,
most services are provided without good evidence of benefit.