Analysis of Ordering Practice of Thrombophilia Testing at a Single Large Teaching Hospital

• Published in: Blood 2010-11, Vol.116 (21), p.3188-3188
• Main Authors: Tsai, Judy Peih-Ying, Taiwo, Evelyn O., Cervantes, Natalie, Jasso, Guadalupe, Frenkel, Eugene P., Sarode, Ravindra, Shen, Yu-Min
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V116.21.3188.3188

Abstract 3188 Thrombophilia describes either an inherited or acquired predisposition to thrombosis. There are no well defined guidelines for thrombophilia testing. Thus, testing after a single episode of thrombosis in unselected patients has become a common yet often inappropriate practice. An ideal work-up includes: antithrombin (AT) activity, protein C (PC) activity, protein S (PS) activity and antigen (total and free), activated protein C resistance (APC-R), factor V Leiden (FVL) if the APC-R is abnormal, prothrombin gene mutation (PGM), factor VIII (FVIII) and antiphospholipid antibodies (aPL) (lupus anticoagulant, anti-cardiolipin, and anti-β2 glycoprotein I, IgG, M and A). The purpose of this retrospective observational study was to characterize the pattern of such thrombophilia testing at a single large teaching hospital. All laboratory requests for thrombophilia testing in October and November of 2009 were included in this retrospective evaluation. The tests included were PC, PS, AT, FVIII, FVL, PGM, homocysteine and aPL. Clinical information was extracted from electronic medical records and analyzed for indication and timing of testing, completeness of the tests, whether the tests were performed on anticoagulation, and whether an abnormal test result was repeated to confirm the diagnosis. The study consisted of 100 consecutive patients (69 females, 68 less than 50 years of age). 70 patients had a known event prior to thrombophilia testing, 34 had an inappropriate indication [provoked thrombosis, 1–2 pregnancy losses, pre-eclampsia] (Table 1). 88% of the patients who were tested had an incomplete workup for the indication. Of the 70 patients who had an identifiable event prior to testing for thrombophilia, 41 patients were tested at the time of the event (