Low molecular weight heparin versus unfractionated heparin in the colonoscopy peri-procedure period: a cost modeling study.

OBJECTIVE: The aim of this study was to compare the economic outcomes of peri-procedure anticoagulation approaches for elective colonoscopy.

METHODS: Decision analysis was used to model the economic outcomes of five peri-procedure anticoagulation options: outpatient low molecular weight heparin (LMWH), inpatient unfractionated heparin infusion (UFHi), continuous warfarin (with probability of a repeat procedure using LMWH or UFHi), and discontinuation of anticoagulation therapy. The model's base-case scenario assumed drug therapy options for high-risk patients were equally effective in preventing a thromboembolic event (0.1% risk), with a higher probability for the no anticoagulation strategy (0.4%); event costs were based on published data and adjusted to 1997 dollars. Drug costs reflected 1997 average wholesale price. Medical costs for other variables were estimated based on local hospital charges. Indirect costs were not considered. Risk probabilities and LMWH drug cost were tested in sensitivity analysis.

RESULTS: In the base-case scenario, costs for the options evaluated were $1436/patient, $1792/patient, $1848/patient, $2629/patient, and $5196/patient for no anticoagulation, continuous warfarin/repeat LMWH, LMWH as outpatient, continuous warfarin/repeat UFHi, and UFHi as inpatient respectively ($1997). Discontinuing anticoagulation was the least costly approach but involved the greatest thromboembolic risk. The cost of continued warfarin anticoagulation/repeat LMWH was minimally less than the LMWH option, but assumes 25% of patients would require a second procedure. The traditional approach (UFHi) requires an extended hospitalization and is the most costly option. Varying risk category or LMWH cost in sensitivity analysis had a negligible impact on overall costs.

CONCLUSION: Within the model's assumptions, LMWH offers a novel, convenient, and economical solution to the problem of peri-procedure anticoagulation for elective colonoscopy.