Venous thromboembolism (VTE) is a common cause of serious morbidity and mortality, and patients with cancer are at particular risk. “VTE has a substantial burden on the current US medical system. Its preventable costs and indirect costs from premature deaths are substantial,” said Alex C. Spyropoulos, MD, of McMaster University, Hamilton, Canada.
Dr Spyropoulos and colleagues developed a decision tree and cost model to estimate the national healthcare costs for pulmonary embolism (PE), total hospital-acquired PE, and total preventable PE. The model demonstrated annual savings of $4.6 billion to $14.3 billion in the base model, and as high as $12.8 billion to $42.2 billion when adjusted to 2011 US dollars in the sensitivity analysis.
The authors concluded that “appropriate type, dose, and duration of prophylaxis is cost-effective.”
VTE Prophylaxis Is Cost-Effective
Other investigators from the University of Pittsburgh agreed that VTE prophylaxis is cost-effective. As background, they noted that despite evidence that low-molecular-weight heparin (LMWH) has antitumor effects and improves short-term survival, the cost-effectiveness of anticoagulation in ambulatory cancer patients is unknown.
Allyson Pishko, BS, and colleagues constructed a Markov model to evaluate prophylactic anticoagulation with enoxaparin in such patients with no previous VTE during 4 months of chemotherapy. The model used data from a 2011 Cochrane Review of 9 randomized controlled studies of cancer patients with no indication for anticoagulation prophylaxis. The researchers measured medical costs, effectiveness (measured by mortality reduction), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) over a 24-month period. Enoxaparin 40 mg/day was estimated to cost $1132 per month.
The cost of treating a major bleeding event was $5317 and the cost of a minor bleeding, $73. Death was calculated at $5000. Compared with no LMWH, 4 months of primary prophylaxis with enoxaparin was associated with a relative mortality risk of 0.92 over 24 months, at a gain of 0.0484 QALY, for an ICER of $76,922 per QALY gained. The relative risk for deep-vein thrombosis was 0.55.
“This is well within the accepted $100,000/QALY threshold,” Ms Pishko said. However, if the ICER increases to >$100,000 per QALY, it may no longer be considered cost-effective.
“Prophylactic anticoagulation appears to be cost-effective in ambulatory cancer patients during the first 4 months of chemotherapy. If the suggested mortality benefit is confirmed by additional randomized controlled studies, administering anticoagulation to ambulatory cancer patients during high-risk chemotherapy treatments should be considered,” she concluded.
Electronic Reminder Enhances VTE Prophylaxis
The use of an electronic “smart order set” to remind physicians about VTE risk boosted the use of VTE prophylaxis within Johns Hopkins Hospital. The intervention also dramatically reduced the rate of symptomatic VTEs, reported Amer M. Zeidan, MD, of Johns Hopkins University.
A review of patient records showed that risk-appropriate prescribing rates rose from 68% to 86% when the smart order set was added to the institution’s decision support (P <.001). The rate of VTE episodes within 90 days of admission fell from 2.5% to 0.7% (P = .002), as a result of VTEs that occurred postdischarge: the rates of major bleeding did not increase with the use of VTE prophylaxis.
This intervention was developed after an internal review showed that VTE prophylaxis was not being prescribed for many patients deemed eligible by national guidelines. “Our results support the use of a mandated risk-adaptive strategy for consideration of VTE prophylaxis for every hospitalized patient,” Dr Zeidan said.—CH