Cost-Effectiveness of Aspirin for Extended Venous Thromboembolism Prophylaxis After Major Surgery for Inflammatory Bowel Disease.

BACKGROUND AND PURPOSE

Venous thromboembolism extended prophylaxis after inflammatory bowel disease surgery remains controversial. The purpose of this study was to evaluate if adopting an aspirin-based prophylaxis strategy may address current cost-effectiveness limitations.

METHODS

A decision analysis model was used to compare costs and outcomes of a reference case patient undergoing inflammatory bowel disease-associated colorectal surgery considered for post-discharge thromboembolism prophylaxis. Low-dose aspirin was compared to an enoxaparin regimen as well as no prophylaxis. Source estimates were obtained from aggregated existing literature. Secondary analysis included out-of-pocket costs. A 10,000-simulation Monte Carlo probabilistic sensitivity analysis accounted for uncertainty in model estimates.

RESULTS

An enoxaparin-based regimen compared to aspirin demonstrated an unfavorable incremental cost-effectiveness ratio of $908,268 per quality-adjusted life year. Sensitivity analysis supported this finding in > 75% of simulated cases; scenarios favoring enoxaparin included those with > 4% post-discharge event rates. Aspirin versus no prophylaxis demonstrated a favorable ratio of $106,601 per quality-adjusted life year. Findings were vulnerable to a post-discharge thromboembolism rate < 1%, aspirin-associated bleeding rate > 1%, median hospital costs of bleeding > 3 × , and decreased efficacy of aspirin (RR > 0.75). The average out-of-pocket cost of choosing an aspirin ePpx strategy increased by $54 per patient versus $708 per patient with enoxaparin.

CONCLUSIONS

Low-dose aspirin extended prophylaxis following inflammatory bowel disease surgery has a favorable cost-safety profile and may be an attractive alternative approach.