Analysis of Thrombophilia Test Ordering Practices at an Academic Center: A Proposal for Appropriate Testing to Reduce Harm and Cost

Abstract

Ideally, thrombophilia testing should be tailored to the type of thrombotic event without the influence of anticoagulation therapy or acute phase effects which can give false positive results that may result in long term anticoagulation. However, thrombophilia testing is often performed routinely in unselected patients. We analyzed all consecutive thrombophilia testing orders during the months of October and November 2009 at an academic teaching institution. Information was extracted from electronic medical records for the following: indication, timing, comprehensiveness of tests, anticoagulation therapy at the time of testing, and confirmatory repeat testing, if any. Based on the findings of this analysis, we established local guidelines in May 2013 for appropriate thrombophilia testing, primarily to prevent testing during the acute thrombotic event or while the patient is on anticoagulation. We then evaluated ordering practices 22 months after guideline implementation. One hundred seventy-three patients were included in the study. Only 34% (58/173) had appropriate indications (unprovoked venous or arterial thrombosis or pregnancy losses). 51% (61/119) with an index clinical event were tested within one week of the event. Although 46% (79/173) were found to have abnormal results, only 46% of these had the abnormal tests repeated for confirmation with 54% potentially carrying a wrong diagnosis with long term anticoagulation. Twenty-two months after guideline implementation, there was an 84% reduction in ordered tests. Thus, this study revealed that a significant proportion of thrombophilia testing was inappropriately performed. We implemented local guidelines for thrombophilia testing for clinicians, resulting in a reduction in healthcare costs and improved patient care.

A clinical audit of thrombophilia testing in pediatric patients with acute thromboembolic events: impact on management

“…The most common positive tests during the acute phase were a positive LA and decreased PS activity, both of which are subject to acute phase effects. 8 Only 1 of these in each category remained positive when tested at 12 weeks or more. By delaying testing until after the resolution of the acute phase, more accurate results can easily be obtained.…”

“…Twelve of 35 patients younger than 1 year (34%), including 1 neonate, had unnecessary blood draws to complete thrombophilia Family history of thrombosis, n (%) 8 (8) testing; all were classified as having provoked TEEs. None of the patients who had false-positive testing were misdiagnosed with a thrombophilia disorder or received unwarranted anticoagulation because of false-positive test results; however, 38% (15/40) of the initial positive tests were not repeated (Table 3).…”

“…This is unlike in the adult population, where many such patients are not followed by hematologists. 8 There is also a substantial potential for misdiagnosis based on erroneous laboratory results if the patient follows up with physicians without hemostasis thrombosis expertise.…”

“…7 In adults, thrombophilia testing rarely affects acute management. 8 However, data are lacking for the pediatric population. There is mounting evidence that thrombophilia testing is overused at many centers.…”

Saddle pulmonary embolism as the initial presentation of prothrombin gene mutation G20210A

“…Not every patient with first time VTE needs to be screened for hereditary thrombophilia, especially those with active cancer, transient risk factors or superficial VTE. Adult patients with the following conditions merit screening for hereditary thrombophilia: unprovoked or idiopathic VTE at a young age (age <40), recurrent idiopathic VTE, warfarin-induced skin necrosis, strong family history of VTE (defined as two or more first-degree relatives or >20% symptomatic relatives) or unexplained spontaneous abortions 1 2. Thrombophilia screening in cases of VTE at unusual sites (eg, intra-abdominal, cerebral vein thrombosis) and arterial thrombosis are still controversial.…”