Justifying Total Costs of Extended Venothromboembolism Prophylaxis After Colorectal Cancer Surgery.

Background: Current guidelines recommend extended venothromboembolism (VTE) prophylaxis for most patients following colorectal cancer surgery, but provider uptake has been limited. The purpose of this study was to identify thresholds for when such extended prophylaxis (ePpx) may be value-appropriate.

Methods: All colorectal cancer postoperative discharges were identified within a private payer administrative database (MarketScan® 2010-2014, IBM Truven Health Analytics). Outcomes of interest were VTE event rate, mortality, and overall costs of care. The data along with published literature were used as parameter estimations for a decision analysis model with probabilistic sensitivity analysis.

Results: We identified 22,463 colorectal cancer surgical patients (4.0% with ePpx) that served as the parameter estimates for the decision model with a VTE event rate of 0.2%. Decision analysis demonstrated that prescribing ePpx was dominated by usual practice with the former having higher probability-adjusted incremental costs ($1078.68 per person) and lower probability-adjusted benefits (- 0.000098 quality adjusted life years). Broad sensitivity analysis found that probability of a VTE event, bleeding case fatality rate, and probability of an ePpx-associated bleeding event were the primary effectors of the model. VTE event rates of greater than 3.0% benefited from prescribing ePpx to all patients.

Conclusions: Very few patients are discharged on ePpx following colorectal cancer surgery despite its endorsement by national guidelines. A decision analysis model does not support the use of ePpx except in cases of markedly high VTE rates. Clinical guidance could be improved by further recognizing the role of risk stratification in the determination of high-risk patients requiring ePpx.