"Pre-pre" and "post-post" analytical error: high-incidence patient safety hazards involving the clinical laboratory.

Data from recent studies suggest that the highest incidence of laboratory-related errors occurs in the pre-analytical phase of laboratory testing. However, few studies have examined the frequency of errors in laboratory test selection and interpretation. A survey of physicians who use our clinical laboratory demonstrated that the largest number of test ordering errors appear to involve physicians simply ordering the wrong test. Diagnostic algorithms providing guidance for test selection in specific disorders are also used as the basis for the establishment of reflex protocols in the clinical laboratory. The provision of an expert-driven interpretation by laboratory professionals resulted in improvements both in the time to and the accuracy of diagnosis. A survey of our physician staff has shown that in the absence of such an interpretation, for patients being assessed for a coagulation disorder, approximately 75% of the cases would have involved some level of test result misinterpretation.