Preanalytic indicators of laboratory performances and quality improvement of laboratory testing.

Laboratory diagnosis is traditionally a three-part process that develops within the preanalytic, analytic and post-analytic phases. There is consolidated evidence that lack of standardization and monitoring of preanalytic variables, including procedures for patient identification, sample collection, handling and processing has an adverse influence on the reliability of test results, consuming valuable healthcare resources and compromising the patient's outcome. The preanalytic phase enfolds the greatest potential for quality improvement, once reliable strategies are identified and applied. A comprehensive quality program should outstrip the traditional confines of clinical laboratories, encompassing reliable monitoring policies of the state of quality across the entire process. Such an approach requires the adoption of a reliable global quality monitoring system based on a core set of broad, evidence-based preanalytic performance measures. The present article synthesizes current evidence on this topic, defining a tentative approach for implementation of a preanalytic quality monitoring system in clinical laboratories.