Venous Thromboembolism Prevention in the Ambulatory Cancer Clinic (VTE-PACC): a Systems-Based, Personalized, Multidisciplinary Program to Increase Venous Thromboembolism (VTE) Risk Assessment, Education and Anticoagulant Prophylaxis in Cancer Outpatients Initiating Therapy

Introduction : Anticoagulant prophylaxis reduces VTE rates by ~50% in selected oncology patients. Among cancer patients starting chemotherapy, 2014 ASCO Guidelines recommend VTE risk assessment, VTE education, and administration of pharmacologic prophylaxis in selected patients. While validated VTE risk stratification tools are available, <10% of oncologists use a risk assessment tool in practice. Further, evidence-based and practical guidance for how to implement VTE prevention guidelines in cancer outpatients is lacking.

Hypothesis : Implementation of a systems-based multidisciplinary program that utilizes the electronic health record (EHR) and offers personalized VTE prophylaxis recommendations by consulting hematologists would increase VTE risk assessment, increase VTE education rates, and increase the rate of VTE prophylaxis in high risk patients initiating outpatient chemotherapy.

Methods: At a tertiary university cancer center, based on a quality improvement framework with an iterative design to refine the intervention over time, VTE-PACC is a multidisciplinary thrombo-oncology program developed and implemented by nurses, oncologists, pharmacists and hematologists. We identified high risk patients, provided standardized VTE education, and tailored prophylaxis for adult cancer outpatients initiating chemotherapy. Patients receiving hormonal therapy or with brain cancer were not included in the program. An assessment of VTE risk using the Khorana and Protecht scores via the EHR was built into clinical process flow and all patients were provided education on VTE symptoms and risk reduction. Patients with a high predicted VTE risk during treatment (defined as ≥3 points on the Khorana or Protecht score) were offered a hematology consultation to consider VTE prophylaxis. Results of the consultation including individualized drug and dosing recommendations were communicated to the treating oncologist.

Results : Between October 1, 2015 and July 1, 2017 (comprising a 6 month implementation phase and subsequent 15 months post implementation), 850 patients were evaluated. VTE risk assessment and education rates increased from less than 5% to 84.3% (range 65.8- 97.6% per month) during the implementation phase. Improvement in EHR documentation processes and clinical work flow resulted in a further increase to 94.9% over the subsequent 15 months. In the post-implementation phase, 153 patients (23.7%) were identified as high risk of VTE based on the Khorana or Protecht scores and offered referral to hematology. The largest patient derived factor for referral acceptance was consultative visits coincident with receiving therapy or an oncology visit. Of these high risk patients, 86% received prophylactic anticoagulation therapy (49% DOAC (direct oral anticoagulant), 32% low molecular weight heparin, 17% unfractionated heparin and 2% warfarin).

Conclusion: The VTE-PACC intervention used a multidisciplinary EHR based approach to improve VTE risk assessment and education rates in cancer outpatients initiating therapy. The great majority of high risk patients also received prophylactic anticoagulation. As large trials on the benefits and risks of pharmacologic prophylaxis are completed, methods applied here may readily translate these findings into practice.