Implementation and validation of a risk stratification method at The Ottawa Hospital to guide thromboprophylaxis in ambulatory cancer patients at intermediate-high risk for venous thrombosis

- VTE is a common complication of cancer leading to significant morbidity & mortality.
- The risk for VTE varies markedly between individual cancer patients.
- Identifying those at intermediate- high risk for VTE may enable better use of VTE prophylaxis.
- Tools to stratify VTE risk in cancer patients have been previously described.
- Validation of these tools and methods to implement them into practice are lacking.

BackgroundCancer patients have a significantly higher risk of developing a venous thromboembolism (VTE) compared to non-cancer patients and yet studies suggest VTE risk among ambulatory cancer patients varies widely. Recently, predictive models capable of risk-stratifying a broad range of ambulatory cancer outpatients have been developed. Using the Khorana model a score of 2 was intermediate-high risk for VTE as reported by Ay and colleagues. However, validation in a broader population and methods to implement this model seamlessly into clinical practice are lacking.ObjectiveTo create and assess the feasibility of an innovative computerized Care Process Management System (CPMS) that would automatically access electronic medical records to calculate in real-time the risk of VTE in patients with active cancer using an established VTE risk scoring system.MethodsA prospective observational study of all newly referred cancer patients at the Ottawa Regional Cancer Center, the sole cancer care provider for 1.2 million inhabitants, was conducted.Results699 new referrals were determined to have a cancer diagnosis for the first time as identified by the computer software and qualified for our study and 580 were eligible. In total 25% had intermediate-high risk for VTE and during the 3-month follow up period, 16 of the 143 (11%) developed a VTE which further validates the Khorana model for identifying intermediate-high risk patients. Of the 437 patients in the low risk group 19 (4%) developed a VTE.ConclusionNewly diagnosed cancer patients can be readily stratified into intermediate-high and low risk of VTE using our novel CPMS system. This innovative tool can be used to facilitate customized management decisions regarding VTE prophylaxis for intermediate-high risk patients based their individual risk factors.