Critical evaluation of scientific articles and other sources of information: an introduction to evidence-based veterinary medicine.

The purpose of this paper is to briefly review key concepts regarding critical reading of the scientific literature to make informed decisions, in the context of evidence-based veterinary medicine. Key concepts are reviewed, based on the broader experience in human medicine, with adaptations, as indicated, to veterinary medicine. That a paper has been published in a peer-reviewed journal does not guarantee its credibility; guidelines are given regarding the general merit of different kinds of articles, as well as checklists and criteria that can be used to assess a paper. Specific study designs, their merits and limitations, are briefly discussed. Standard numerical indices for assessment of studies involving treatments and for assessments of diagnostic tests are summarized. Criteria for assessing drug trials are presented. The principles of statistical analysis are described, including practical considerations and common errors. Finally, numerous sources of bias are reviewed.