Economic Burden of Venous Thromboembolism in Cancer Patients — a Comparative Analysis between Matched Patients with Cancer with and without a Diagnosis of Venous Thromboembolism

Background:Venous thromboembolism (VTE) is a major health problem occurring at a rate of 1/1000 adults in general population. Cancer patients have a much higher risk of VTE with an annual rate of 24.6/1000 patients and this contributes to significant morbidity and mortality in this patient population. The body of evidence related to the economic burden for VTE in cancer patients is limited to small institutional studies. With increasing burden of cost for cancer care there is a significant push for cost containment measures, physicians taking care of these patients should be more aware of the economic outcomes of their patient cares.

Methods: We used a large claims based data set US database MarketScan (Truven Health Analytics) to explore the economic burden of VTE in cancer patients. Between January 1, 2013 and September 30, 2015 we identified 614,577 patients with cancer of these 195,290 were deemed to have active cancer out of which 6,569 had a VTE code in their medical claims. This study was conducted to assess the economic burden of VTE in cancer patients in comparison their non-VTE peers with similar cancer type.

All-cause costs over 3-year period were used and included the costs of all services. These were further explored to compare the total cost of care, cost based on the site of utilization of care and pharmacy cost between the patients with VTE with their matched peers. VTE-related costs were identified with a primary or secondary diagnosis of DVT or PE, and were evaluated for the entire follow-up period, starting from the initiation of the anticoagulant therapy until end of eligibility or end of data, whichever was earlier. Continuous factors were summarized by the median. Wilcoxon signed-rank tests were used to test for differences in the distribution between the VTE and non-VTE groups for cost and number of visits. Overall costs as well as total cost per day/visit were compared between groups. The costs were also evaluated by site of utilization (Emergency room vs inpatient vs outpatient) and by cancer subtype.

Results:

Among active cancer enrollees, there were 6,569 (3.4%) enrollees with VTE and 188,721 (96.6%) without. Average age was around 60 years in both groups. There were approximately 50 % females in each group and breast cancer was the most common type of cancer in the non-VTE group while gastrointestinal cancers were more common in the VTE group. Incidence of comorbid conditions like diabetes, hypertension and chronic kidney disease was similar in both cohorts but chronic liver disease was found more often in the VTE cohort. The median total cost over the study period for the VTE group ($136,976) was 2.0 times that of the non-VTE group ($67,115). This pattern holds for the inpatient, emergency, and outpatient costs. Total median drug costs were about 4 times that of the VTE group ($10,457) than the non-VTE group ($2,621). The difference the cost between groups for these measures were all highly statistically significant (<0.001). However, the VTE group also had 1.7 times the median number of days/visits than the non-VTE group (p < 0.001 for all categories). After adjusting for the number of days, the median total cost per visit was still statistically significant (p<0.001); however the cost difference is much smaller ($1,132 in VTE vs. $984 in non-VTE,). The overall total cost in the VTE groups ranges from 1.3 (pancreatic) to 3.4 (other cancers) times that of the non-VTE patients for the various cancer types, all were statistically significant (p<0.001). After adjusting for the number of visits, the relative cost difference decreased for all cancer groups it ranges from 0.97 (gynecological) to 1.5 (other cancer) times that of the non-VTE patients for the various cancer groups. Lung, breast, gastrointestinal, and other types were statistically significant (p < 0.01).

Discussion:

Based on the real world information from a large insurance claims database, this study quantifies the incremental health care cost burden associated with VTE in cancer patients. It is clear from this study the patients with cancer and VTE seek medical care more frequently than their non-VTE counterparts leading to higher healthcare costs in all settings. It was also interesting to note that when only the drug costs were taken into consideration, enrollees with VTE had up to 4 times higher drug costs, not all of which was attributable to the anticoagulant cost.