The evidence-based recommendations for the evaluation of new tests to be used in practice are a key issue to improve diagnostic clinical pathway inducing effective care. Emerging precision or personalized medicine requires innovative and pioneering biomarker tests for molecularly targeted therapies, possibly fitted for the individual patient's condition. Beyond the traditional analytical specifications that should guarantee the proper clinical diagnostic performances in response to a specific clinical question, the outcomes of a new test should be clearly defined and evaluated. Analytical and diagnostic performances such as sensitivity, specificity, imprecision, positive and negative predictive values are traditionally established measures but the clinical impact and the healthcare outcomes, to which these accuracy measures are related, are complex to measure. The extent of the improvement of the patients' health due to a diagnostic test remains a "holy grail" notwithstanding it should be the ultimate goal.
Keywords: GRADE; clinical diagnostic outcomes; evidence-based laboratory medicine; guidelines; test evaluation.