Evaluation of Inpatient Thrombophilia Pathway

Introduction:

Venous thromboembolism (VTE) ranges from asymptomatic deep vein thrombosis (DVT) to fatal pulmonary emboli (PE). VTE is the third most common cardiovascular illness and cause of mortality after acute coronary syndrome and stroke. Medical societies such as American Society of Hematology (ASH), British Society for Haematology, and Society for Vascular Medicine have all created selection criteria, consistent with each other, for when to order a hereditary thrombophilia workup. Guidelines indicate that thrombophilia testing should not be offered to patients who are continuing anticoagulation treatment, or to those who have had "provoked" VTE. Examples include patients who have had a transient risk factor within the past 3 months including surgery, trauma, prolonged immobility, pregnancy or puerperium, and patients on hormonal therapy. The aims of our study is to identify the prevalence of hypercoagulable testing in our hospital, evaluate how our organization follows certain criteria for patients presenting with DVT or PE, and to calculate the economic impact of ordering these workups unnecessarily.

Methods

We conducted a retrospective chart review from July 2014 to June 2015 that identified individuals that were admitted to the hospital with a diagnosed DVT or PE detected by lower extremity doppler ultrasound or computed tomography of the lungs. Inclusion criteria included newly diagnosed patients with DVT or PE. Frequencies were calculated for sex, work-up, ethnicity, smoking, estrogen therapy, malignancy, and history of VTE. Further analysis was run using work-up as predictor variable and cross tabulated with sex, ethnicity, smoking, estrogen therapy, malignancy and history of VTE. Independent t-test were conducted between work-up and age and BMI levels.

Results

We identified 241 patients admitted to the hospital for DVT or PE. Within this population, 57 individuals (23.7%) had the hypercoagulability pathway. A majority of the patients within this subpopulation were female (57.9%). Sensitivity analysis for the 57 individuals who underwent work-up also included 38.6% with a smoking history, 3.5% on estrogen therapy, 86% without history of malignancy, 40.4% with history of previous DVT or PE, and 89.5% of the patients being Caucasian. The average age and BMI was 55 and 32.9 respectively. No significant relationship was found between the work-up and sex (p= 0.11), ethnicity (p=.65), smoking (p=0.46), estrogen therapy (p= 0.8), without malignancy (p=.051), and history of DVT or PE (p=0.12). There was a significant relationship between age and work-up (p=0.002), with younger patients more likely to have the work-up.

Conclusion

Our study indicated that younger patients presenting with VTE were likely to under go work-up for thrombophilic disorders. Patients without malignancy and those who did not smoke were also more likely to undergo a work-up. In addition to this, women not on estrogen therapy were less likely to receive a work-up. Even though our results allude to inappropriate thrombophilia testing, we lack statistical significance due to our population size and patient diversity.

These tests are expensive, with costs approaching $3,000 for a full thrombophilia panel. This totals around $100,000 to $160,000 of cost savings for the 53 individuals that had the work-up within the one year span. This cost analysis does not include the expense accrued by the patient for prolonged anticoagulation plus the ongoing lab costs of INR monitoring. Research should be further investigated in a larger and more diverse population for better understanding for the role of thrombophilia evaluation in the inpatient setting.