What is evidence-based medicine?
Evidence-based medicine (EBM) is "the integration of strongest available evidence to make informed unbiased decisions about the diagnosis and treatment of patients" . According to Sackett et al., EBM is the "conscientious, explicit and judicious use of the current best evidence in making decisions about the care of individual patients" .
What is evidence-based laboratory medicine?
Rephrasing these definitions [1-2]: EBLM integrates into clinical decision-making the best available research evidence for the use of laboratory tests with the analytical and clinical expertise and experience of health care professionals and the needs and expectations of patients.
The aims of EBLM are:
• to support clinical and policy decisions and patient choices
regarding the utilization of laboratory investigations,
• to improve the care and outcomes of individual patients, and
• to support the effective use of health care resources.
This involves complex pathways. Clinical decisions are complex, and the evidence is only one element in the process. Evidence should therefore always be assessed in close collaboration between clinicians and specialists in laboratory medicine. Making evidence-based diagnostic decisions requires:
• familiarity with the clinical problem, including the clinical needs of both patient and clinical staff,
• knowledge of the analytical and diagnostic performance and limitations of the tests,
• consideration of the clinical impact, and
• locally available human, technical and financial resources .
Best available research evidence is defined as systematically compiled and critically appraised information, preferably coming from well-designed primary studies, to answer a specific clinical question .
Adapting this to our profession, we suggest the following definition:
Evidence in laboratory medicine is systematically compiled and critically appraised information, preferably from well-designed primary studies, to answer a specific question on the utility of laboratory tests in diagnosis, screening, monitoring, risk assessment and prognosis.
The best research evidence for the clinical utility of laboratory tests provides an explicit framework to making informed decisions by patients, clinical staff or representatives of health policy.
Systematic reviews are overviews of multiple primary studies which locate, appraise and synthesize the evidence in a systematic way, according to predefined methodology. Systematic reviews aim to gather all available, relevant and valid scientific data, and analyze and pool the results in a way to maximize precision of conclusions, while avoiding bias. Practice guidelines, economic evaluations, technology appraisal reports often integrate the findings of systematic reviews.
When the results of multiple primary studies are not only summarized in a qualitative manner, but also combined statistically, it is called a meta-analysis. In other words, there are two types of systematic reviews, one without and the other with meta-analysis. The term "overview" is sometimes used to denote both types of systematic reviews.
Clinical guidelines are systematically developed statements that assist doctors and other health care professionals in making decisions about the appropriate and effective care for their patients .
 Evidence-Based Medicine Working Group. Evidence-based medicine. A new approach to teaching the practice of medicine. JAMA. 1992 Nov 4;268(17):2420-5.
 Sackett DL, Richardson WS, Rosenberg W, Haynes RB (eds). Evidence-based Medicine. How to Practice and Teach EBM. Churchill Livingston, London, 1997; pp250.
 Price CP. Evidence-based Laboratory Medicine: Supporting Decision-Making. Clin Chem 2000; 46: 1041-1050.
 Field MJ, Lohr KN, eds. Guidelines for clinical practice. From development to use. Washington, DC: National Academy Press, 1992. 426pp.