## Abstract

Abstract 2476

Poster Board II-453

Introduction:

It is unknown whether it is cost effective to screen adolescents with menorrhagia for von Willebrand disease (VWD) prior to starting oral contraceptive pills (OCPs). Because OCPs can mask a diagnosis of VWD, a woman is at risk for potential future traumatic or surgical bleeding, once OCPs are stopped. We, therefore, designed a decision analysis model to evaluate the cost utility of VWD testing in adolescents with menorrhagia.

Methods:

A 20-year Markov decision analytic model was constructed to evaluate the cost-utility of two strategies: testing or not testing for VWD. The hypothetical patient is a 15-year-old female presenting with menorrhagia and a decision regarding VWD testing is made. The model includes probabilities of remaining well, suffering an acute menorrhagia bleeding event, surgical complications, OCP complications or dying. Probabilities, costs and utilities were estimated from published literature. The prevalence of type 1 VWD in adolescent females with menorrhagia was estimated to be 13%. We assumed all patients were treated with OCPs regardless of whether hemostatic testing was performed. All patients were assumed to have mild type I VWD, the most common subtype, and all were responsive to intravenous DDAVP. Probabilities of surgical complications in patients with and without VWD were based on adenotonsillectomy hemorrhage rates in children. The probability of acute menorrhagia bleeding necessitating hospitalization or red blood cell transfusion was estimated to be 1% in an adolescent with VWD and 0% in an adolescent with normal hemostatic testing. The sole complication from OCPs incorporated into this decision analytic model was acute deep vein thrombosis.

Results:

The cost of testing adolescents with menorrhagia for VWD was $1,638, vs.$1,251 for not testing for VWD. The effectiveness of not testing in quality-adjusted life-year (QALY) gained (14.237 QALY) was similar to the VWD testing strategy (14.246 QALY). Compared to not testing for VWD, screening for VWD had an incremental cost-effectiveness ratio (ICER) per QALY of $45,061/QALY, a value typically considered economically reasonable. In one-way sensitivity analysis, the outcome and ICER were most sensitive to the probabilities of an acute bleeding event, surgical complication, and the prevalence of VWD. Monte Carlo probabilistic sensitivity analysis, substituting input distributions rather than a single point estimate for the probabilities, costs and utilities, was also performed. Under this assumption, testing for VWD is a cost-effective strategy approximately 60% of the time when the cost-effectiveness threshold is$100,000/QALY.

Conclusions:

It is cost effective to perform VWD testing in adolescents presenting with menorrhagia prior to initiating OCPs. This is related to avoiding cost from postoperative and other bleeding when the diagnosis is masked by OCPs.

Disclosures:

No relevant conflicts of interest to declare.

## Author notes

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Asterisk with author names denotes non-ASH members.