Laboratory Medicine: Reference Values and Evidence-Based Medicine
Accurate and reliable laboratory tests are essential for appropriate clinical management. Individual variability means that there are wide ranges in laboratory test results that are nonpathological and it is necessary for reference intervals to be defined in statistical terms. Rational interpretation of laboratory tests is a critical part of the clinical decision-making process and must take account of not only the test value but also the clinical condition. Evidence-based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients; it means avoiding doing laboratory investigations without a specific clinical suspicion.