Meta-analysis, which uses systematic methods to search, combine, and evaluate research literature, has been praised for making the review article more scientific and objective. But studies showing that journals are much more likely to publish the results of positive over negative clinical trials have led some to question the validity and objectivity of meta-analyses. Many in the medical community are concerned that this publication bias may skew the results of meta-analyses, which increasingly are used by doctors in devising recommendations for patient treatment. In hopes of reducing this publication bias, some critics are pushing for a registry of unreported trials. But citing problems like the poor experimental design of many unpublished studies, other critics question if the registry can improve the validity of meta-analyses.
REGISTRY REJECTION: New England Journal of Medicine's Jerome Kassirer is concerned about the quality of unreviewed research.