Does the standardized template bleeding time accurately reflect platelet function in vivo?
The standardized template bleeding time is a suitable screening test that accurately measures the overall hemostatic role of platelets in vivo.
The value of the standardized template bleeding time was studied in 100 normal subjects and 136 patients with various disorders. With normal platelets the bleeding time in this test is 4.5 ± 1.5 minutes (± 1 S.D.) when the circulating platelet concentration exceeds 100,000 per microliter, and is 30.5 – (platelet count per μl/3850) minutes at platelet counts between 100,000 and 10,000 per microliter. More prolonged bleeding times reflect impaired platelet function, as associated with acetylsalicylic acid ingestion, uremia, or von Willebrand's disease. In contrast, bleeding times shorter than predicted with normal platelets are due to increased hemostatic competence of young platelets, associated either with idiopathic thrombocytopenic purpura or with bone-marrow recovery after chemotherapy. The standardized bleeding time measures the overall hemostatic role of platelets in vivo, and is thus suitable for systematic screening.
Harker et al. (Thu,) studied this question.