Management of venous thromboembolism in cancer patients: the economic burden of hospitalizations
BACKGROUND Patients with venous thromboembolism (VTE) are at increased risk of developing recurrent VTE and post-thrombotic syndrome (PTS), a complication of deep vein thrombosis (DVT) characterized by venous reflux and residual venous obstruction that may manifest as chronic pain and swelling. Therefore, formulary/policy decision makers should understand the clinical and economic consequences associated with VTE. OBJECTIVES To describe the real-world clinical complications, such as recurrent VTE and PTS, associated with VTE and quantify the incremental direct all-cause and potentially disease-related health care costs associated with VTE. METHODS Health insurance claims between January 2004 and December 2008 from the Ingenix Impact database were used. Adult patients with an initial VTE diagnosis (index DVT, pulmonary embolism [PE], or both) with at least 12 months of enrollment prior to the index VTE were matched 1:1 with comparison patients without VTE. Matching criteria included demographic factors, baseline health care costs, and diagnoses of VTE risk factors such as multiple traumas, malignant cancer, or major surgery. Each patient's observation period began on the date of the index VTE, or corresponding study index date for comparison cases, and ended on the earliest of 1 year after the study index date, the health plan disenrollment date, or December 31, 2008. The proportions of patients with (a) recurrent hospital-documented VTE, defined as an inpatient episode with a diagnosis of VTE in any claim field; (b) PTS; and (c) other potentially disease-related diagnoses (thrombocytopenia, superficial venous thrombosis, venous ulcer, pulmonary hypertension, stasis dermatitis, and venous insufficiency) were calculated. Health care costs were defined as standardized net provider payments after subtraction of member cost-sharing amounts. All-cause incremental health care costs and disease-related costs, defined as provider payments for hospitalization or outpatient claims with a primary or secondary diagnosis of VTE, PTS, or any of the potentially disease-related diagnoses, were computed. Costs were calculated per patient per year (PPPY) by weighting each patient's total cost for up to 1 year post-index by the length of follow-up. RESULTS The matched VTE and no-VTE cohorts included 16,969 subjects in each group. The index VTE event was DVT, PE, or both in 12,711, 2,473, and 1,785 patients, respectively. In the VTE cohort, the risks of recurrent VTE and PTS during the follow-up period (mean [SD] observation of 271.7 [121.6] days) were 3.6% and 7.1%, respectively. Patients with VTE had significantly higher average PPPY all-cause costs compared with the no-VTE patients (mean [SD] $33,531 [$70,393] vs. $17,590 [$42,011]; cost difference = $15,941, 95% CI = $14,819-$17,012). Corresponding potentially disease-related health care costs PPPY were also significantly higher for the VTE group (mean [SD] $3,141 [$17,055] vs. $228 [$3,221]; cost difference = $2,913, 95% CI = $2,693-$3,157) and represented 18.3% (i.e., $2,913 of $15,941) of the all-cause cost difference between the 2 groups. CONCLUSIONS In this large matched-cohort study, VTE was associated with a 3.6% risk of hospital-documented recurrence and a 7.1% risk of PTS up to 1 year after index VTE. Potentially disease-related costs represented approximately one-fifth of the incremental all-cause costs associated with VTE.