Bleeding time. A guide to its diagnostic and clinical utility.

Although the bleeding time is the most widely used clinical test employed to assess platelet function, its indications are poorly defined. The test is commonly used as a preoperative screen to predict hemorrhage, but the data supporting this indication are contradictory at best. In this review we highlight the physiologic basis for the bleeding time and survey the literature for data supporting the valid indications for its use. The bleeding time is a useful test for assessing platelet function in patients with hemorrhagic disorders. Its utility in providing helpful clinical information in patients who do not have a known bleeding diathesis by history is minimal. Specific recommendations regarding the rational use of the bleeding time for the preoperative evaluation of patients are presented.