Evidence-based guidelines in laboratory medicine: principles and methods.

BACKGROUND Guidelines are commonly used tools for supporting medical decisions. Formulating evidence-based recommendations has become a leading principle in guideline development. AIM This narrative review integrates the most recent methods of evidence-based guideline development and adapts those to the field of laboratory medicine. SUMMARY We present a 10-step process and a list of criteria for the development of laboratory guidelines. Laboratory guidelines should be outcome oriented, be developed by a multidisciplinary team, and begin with a clear statement of the clinical question(s) that the use of the test(s) is addressing. The clinical questions define the type of study designs that offer the best evidence to answer those questions. Guidelines should be based on the critical appraisal and systematic review of literature and explicitly state the strength of evidence supporting each recommendation. Pragmatic considerations dictate that priority is given to topics with the highest clinical or economic impact. Scientific evidence is necessary but insufficient for recommendations, as considered judgment is required about benefits, harms, costs, and local applicability of recommendations. Formal consensus methods are needed when the evidence base is lacking or controversial. Guidelines should be disseminated widely and their impact monitored regularly. Regular reviewing is needed because the lack of timely updates is a major cause of nonadherence to guidelines. CONCLUSIONS Guidelines should be developed in a transparent process by a multidisciplinary team, with graded recommendations based on critically appraised scientific studies. Systematic, standardized, and explicit methodology, adapted to laboratory medicine, should be followed when developing recommendations involving the use of laboratory tests.