scope:

This document provides guidelines regarding preanalytical, analytical, and postanalytical (preexamination, examination, and postexamination) elements of testing including, but not limited to:

• A description of the value of clinical determination of the pretest probability (PTP) of venous thromboembolism (VTE)

• The proper collection and handling of the specimen

• Assays used for D-dimer analysis

• Establishment of the threshold for exclusion of VTE and its interpretation related to the reference interval (RI)

• Interpretation of test results

• Aspects of regulatory and accreditation requirements

The guideline is intended for clinical laboratorians and laboratory directors, for manufacturers of the methods used to perform the test, for clinicians with an interest in the laboratory elements of the tests, and for regulatory and accrediting agencies overseeing the use of D-dimer for this purpose.

This guideline is not intended for use by patients with clinical conditions that require D-dimer evaluation. Patients reading this document are encouraged to discuss its content with their health care providers. Issues of intermethod standardization or the development of calibrators for standardization are discussed; however, guidelines regarding standardization and calibration are beyond the scope of this document. The document does not address other clinical settings in which the measurement of D-dimer may be clinically useful, including diagnosis and monitoring of overt and nonovert disseminated intravascular coagulation (DIC); risk of recurrence of VTE following the completion of anticoagulant therapy; detection of occult malignancy; staging or risk stratification of diagnosed malignancy; risk of future myocardial infarction in patients presenting with chest pain; and evaluation for subarachnoid hemorrhage.² Studies have demonstrated some value in the combined use of the D-dimer and ultrasonography in the exclusion of VTE. However, the focus of this document is the value of D-dimer to potentially avoid the need for imaging studies. The combined use of D-dimer with imaging studies in the evaluation of VTE is not addressed.