Near Universal Underestimation of the Risk of Recurrent Venous Thromboembolism (VTE)- an Institutional Survey of Thrombophilia

Introduction: Current guidelines suggest consideration of indefinite anticoagulation for patients with unprovoked proximal deep vein thrombosis (DVT) and pulmonary embolism at low to intermediate risk for bleeding. In clinical practice, many patients are not treated with prolonged anticoagulation placing them at an increased risk for recurrent VTE. An underappreciation of the risk of recurrent thrombosis may result in the premature discontinuation of anticoagulation in some high-risk patients.

Methods: An online, anonymous questionnaire was sent to all physicians and advanced practice providers in a 711-bed academic community hospital inquiring about their practice, specialty, medical degree, years in practice, and basic questions regarding their comfort and frequency of prescribing anticoagulants. The questionnaire also asked the providers how they would manage ten various clinical scenarios related to anticoagulation management. The participants were graded and scores were calculated based upon percent correct. One question asked the clinicians to estimate the five-year risk of recurrent thrombosis off anticoagulation in a 70-year-old male after completing one year of therapeutic anticoagulation for an unprovoked proximal DVT. The choices given ranged from 1% to 30%. Data was de-identified, SPSS was used to perform t-test and descriptive analysis.

Results: Only 63 (15%) out of 420 respondents appreciated that there is approximately a 30% risk for recurrent VTE after stopping anticoagulation. A slight majority felt that the risk was 5% or less (55.9%). Approximately one-third (29.1%) estimated the risk to be 15%. In the context of practice setting, 22 (37%) from 109 (27%) in-patient providers answered the question correctly, compared to 11 (18%) from 97 (24%) of out-patient providers. In terms of experience, providers with an experience of >10 years (30, 50% correct from 162, 40% responses) did better compared to providers with <10 years of experience (30, 50% correct form 242, 60% responses). t-test results show that providers who answered correctly (30% recurrence), have significant better scores (mean 70.50), compared to those who answered it wrong (mean 57.01), with p-value<0.001.

Conclusion: Underestimation of the risk of recurrent VTE was pervasive in a large, academic healthcare system. It seems likely that this knowledge gap exists outside our institution, and it very likely contributes to premature termination of anticoagulation in some high-risk patients. Quality improvement efforts are needed to educate providers about VTE recurrence risk.