Quality indicators to detect pre-analytical errors in laboratory testing.

Pre-analytical steps, the major source of mistakes in laboratory diagnostics, arise during patient preparation, sample collection, sample transportation, sample preparation, and sample storage. However, while it has been reported that the pre-analytical phase is error-prone, only recently has it been demonstrated that most errors occur in the 'pre-pre-analytical phase'. This comprises the initial procedures of the testing process performed by healthcare personnel outside the laboratory walls and outside the direct control of the clinical laboratory. Quality indicators (QIs) should therefore cover all steps in the pre-analytical phase, from test requesting to sample storage. In the present paper, the state-of-the-art of QIs in laboratory testing is described. The focus is on the experience of a working group of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) in developing a model of QIs, 16 of which concern the pre-analytical phase.