Evidence-based medicine in dermatology

EBM is the use of the best current evidence in making decisions about the care of individual patients. Practicing EBM requires five steps: (1) formulating well-built clinical questions, (2) finding the best evidence to answer the questions, (3) critically appraising the evidence, (4) applying the evidence to specific patients, and (5) saving the critically appraised evidence. The Cochrane Library is the best source for finding the best evidence about treatment. The second best method for finding evidence about treatment and the best source for finding most other types of best evidence in dermatology is by searching the MEDLINE database using the PubMed Clinical search engine of the National Library of Medicine (http://++www.ncbi.nlm.nih.gov/PubMed/clin ica l.html). MEDLINE searches have inherent software and operator limitations that make their reliability quite variable. The quality (strength) of evidence is based on a hierarchy of evidence: results of systematic reviews of well-designed clinical studies, results of one or more well-designed clinical studies, results of large case series, and expert opinion. Once the best evidence has been found, the EBM approach involves critically appraising the quality of the evidence, determining its magnitude and precision, and applying it to the specific patient. Guidelines to appraise critically and apply evidence are available. The clinical question, best evidence, and its critical appraisal should be saved in a format that can be easily retrieved for future use.