This post courtesy of Anne Taylor-Vaisey.
From the August 20 BMJ:
Systematic review of publication bias in studies on publication bias
Hans-Hermann Dubben, Hans-Peter Beck-Bornholdt
BMJ 2005:433-434, doi:10.1136/bmj.38478.497164.F7
Publication bias is a well known phenomenon in clinical literature,1 2 in which positive results have a better chance of being published, are published earlier, and are published in journals with higher impact factors. Conclusions exclusively based on published studies, therefore, can be misleading.3 Selective underreporting of research might be more widespread and more likely to have adverse consequences for patients than publication of deliberately falsified data.1 We investigated whether there is preferential publication of posit! ive papers on publication bias.