A serious problem of publication bias

Steve Simon


I was browsing a paper by Leonard Leibovici [Medline] about alternative medicine when a comment by Andrew Vickers in the eletters section caught my eye. He noted the serious problem of publication bias in Chinese journals. Apparently, the Chinese journals almost never publish a negative trial. He cites two sources: Vickers et al 1998 CCT [Medline] and Tang et al 1999 BMJ [Medline].

I only have the abstract of the Vickers paper, but the numbers quoted there are astounding. In studies of accupuncture, every single trial published in China was positive. In areas other than acupuncture, 99% of the trials were positive.

You can find an earlier version of this page on my original website.