Bias in meta-analytic research

J Clin Epidemiol. 1992 Aug;45(8):885-92. doi: 10.1016/0895-4356(92)90072-u.


With the proliferation of meta-analyses in the medical literature have come conflicting studies. In addition, observance of guidelines for the performance of meta-analyses has been spotty. Bias may explain conflicting studies and differentiate carefully performed meta-analyses from others. Meta-analysts may fail to anticipate biases which threaten their study's validity. The three stages at which bias can be injected into a meta-analysis are finding studies, selection of the identified studies for the meta-analysis and extraction of data from the selected studies. This manuscript reviews specific types of bias which are common at each of these stages.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bias*
  • Epidemiologic Methods*
  • Information Storage and Retrieval
  • Meta-Analysis as Topic*
  • Selection Bias