Hematology and coagulation preanalytics for clinical chemists: Factors intrinsic to the sample and extrinsic to the patient

In hematology and coagulation, diligence in the preanalytical phase of testing is of critical importance to obtaining reliable test results. If the sample used for testing is unsuitable, even outstanding analytical procedures and technology cannot produce a clinically-reliable result. Therefore, the intent of this manuscript is to review preanalytical factors intrinsic to the sample that affect the hematology and coagulation testing. Factors intrinsic to the sample (excluding in vivo anomalies) can be controlled, theoretically, by phlebotomists (including nurses) and laboratorians in the preanalytical phase of testing. Furthermore, the management and prevention of such factors is highlighted. Erroneous control of preanalytical factors can produce laboratory errors.