Clinical use of prothrombin and partial thromboplastin times

Clinical use of prothrombin and partial thromboplastin times

The prothrombin time and activated partial thromboplastin time are commonly ordered tests in hospitalized patients. They are often ordered as part of routine admission laboratory testing, despite studies that have shown them to be poor screening tests for coagulation disorders. To evaluate whether prothrombin time and activated partial thromboplastin time determinations are being ordered inappropriately, Erban and associates reviewed the medical records of 372 patients admitted to the internal medicine service of a large university hospital.

In 300 of these patients (80.6 percent), prothrombin time and activated partial thromboplastin time were determined during hospitalization. The authors compared the indications for these tests as documented in the patient’s records with the generally accepted criteria for the appropriate use of these tests (see table). Based on these criteria, at least 70 percent of the tests were not clinically indicated. The inappropriate tests cost almost $61, 000 per year for the medical service.

The authors conclude that review and correction of the inappropriate use of prothrombin time and activated partial thromboplastin time might help hospitals reduce costs and improve patient care. (JAMA, November 3, 1989, vol. 262, p. 2428.) k

Criteria for the Appropriate Use of Prothrombin and Partial Thromboplastin Times

Preprocedure evaluation

Evidence of liver disease on physical examination prior to an invasive procedure

History of malabsorption or malnutrition noted prior to an invasive procedure

Clinical history unavailable prior to an invasive procedure

Any indication listed below if noted or detected prior to an invasive procedure

Evaluation of abnormal bleeding

Active bleeding or evidence of abnormal bleeding on physical examination

History of abnormal, excessive or spontaneous bleeding

Use of anticoagulants

Recent or current use of therapeutic heparin or warfarin

Evaluation of abnormal coagulation

Suspected or proved thromboembolism

Suspected or proved disseminated intravascular coagulation

From Erban SB, et al. Routine use of the prothrombin and partial thromboplastin times. JAMA 1989;262(17):2428-32. Copyright 1989, American Medical Association. Used with permission.

COPYRIGHT 1990 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group