Controlled clinical trials in complementary medicine - outcome, quality and the impact factor

Objective

In parallel with the growing popularity of complementary therapies and the increasing number of publications, the market for new journals in this field seems to flourish. While some articles on the topic are published in journals of mainstream medicine (MM), the majority of papers are reported in specialised complementary medicine (CM) - journals. In an attempt to scrutinize CM-journals, a previous study¹ found a considerable preponderance of positive results (a particular intervention is helpful for a particular condition), consistent with a strong publication bias in favour of positive conclusions. However, these data, obtained from a convenience sample of CM-journals, categorised all published papers. The present study was aimed to systematically assess the outcome of controlled clinical trials (CCTs) in CM, and its relation to methodological quality and publishing journal.

Materials and methods

CCTs were obtained using reviews and meta-analyses as primary source. A Medline search (1990–October 1997) was performed to identify all reviews and meta-analyses of four major complementary therapies. The MeSH terms used were acupuncture, osteopathic medicine, chiropractic, homoeopathy and herbal medicine. Studies were included if individual trial quality was assessed. Reports not related to controlled clinical trials were excluded. All CCTs were classified as positive (significant (p<0.05) difference in favour of verum compared to control), negative (no such difference) or according to author’s conclusion. Methodological quality, journal type (CM-journal or MM-journal) and impact factor were assessed and related to trial outcome.

Results and conclusion

Will be presented at the meeting.

Reference

1. Ernst E, Pittler MH. Alternative therapy bias. Nature 1997; 385: 480.