Clin Biochem Rev. 2012 Feb; 33(1): 13–19

The principles of Evidence-Based Medicine have been established for about two decades, with the need for evidence-based clinical practice now being accepted in most health systems around the world. These principles can be employed in laboratory medicine. The key steps in evidence-based practice, namely (i) formulating the question; (ii) searching for evidence; (iii) appraising evidence; (iv) applying evidence; and (v) assessing the experience are all accepted but, as yet, translation into daily clinical and laboratory practice has been slow. Furthermore, the demand for evidence-based laboratory medicine (EBLM) has been slow to develop.

There are many contrasting observations about laboratory medicine, for example (i) there is too much testing vs insufficient testing; (ii) testing is expensive vs laboratories are expected to generate income; and (iii) test results have little impact on outcomes vs test results are crucial to clinical decision making. However, there is little evidence to support any of these observations. Integrating the principles of EBLM into routine practice will help to resolve some of these issues by identifying (a) where laboratory medicine fits into the care pathway; (b) where testing is appropriate; (c) the nature and quality of evidence required to demonstrate the clinical utility of a test; (d) how the test result impacts on clinical actions; (e) where changes in the care pathway will occur; and (f) where benefit/value can be achieved. These answers will help to establish the culture of EBLM in clinical and laboratory practice.

Clinical Chemistry 46: 1041-1050, 2000;

There is an implicit acceptance that an evidence-based culture underpins the practice of laboratory medicine, in part because it is perceived as the scientific foundation of medicine. However, several reviews of specific test procedures or technologies have shown that the evidence base is limited and in many cases flawed. One of the key deficiencies in the scientific literature on diagnostic tests often is the absence of an explicit statement of the clinical need, i.e., the clinical or operational question that the use of the test is seeking to answer. Several reviews of the literature on specific procedures have also demonstrated that the experimental methodology used is flawed with, in some cases, significant bias being introduced. Despite these limitations it is recognized that a more evidence-based approach will help in the education and training of health professionals, in the creation of a research agenda, in the production of guidelines, in the support of clinical decision-making, and in resource allocation. Furthermore, as knowledge and technologies continue to be developed, an evidence-based strategy will be critical to harnessing these developments.

Figure 2. Evidence of performance designed to facilitate decision-making.

Clinical Chemistry 50: 806-818, 2004

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.

Figure 1. Process of guideline development.