Management of obscure occult gastrointestinal bleeding: a cost-minimization analysis

Abstract

Background & aims: Capsule endoscopy (CE) and double-balloon enteroscopy (DBE) allow complete small-bowel examination but consume additional health care resources. A cost-minimization analysis determined the optimal initial management strategy for obscure occult gastrointestinal bleeding (OGIB).

Methods: We compared 5 strategies: initial small-bowel follow-through, enteroclysis, push enteroscopy (PE), CE, or DBE. Incorporation of multiple tests was allowed with costs taken from a third-party payer perspective. We modeled medically refractory disease with 2 separate model end points in which treatment or definitive diagnosis was necessary and in which visual diagnosis was sufficient to suspend testing. Sensitivity analyses included variations in parameter estimates, Monte Carlo simulation, and structural variations in the model in which DBE was not available as an initial strategy.

Results: When treatment or definitive diagnosis was necessary, the optimal strategy was initial DBE at a cost of $3824. An initial CE strategy costs an incremental $440. CE was preferred when DBE exceeded $1849 or when the sensitivity of DBE decreased to less than 68%. If DBE was unavailable as an initial test then CE was preferred to PE unless CE exceeded $1190, capsule retention was greater than 3%, or 64% of lesions were within reach of PE. When visual diagnosis was sufficient, initial CE was preferred.

Conclusions: For OGIB, initial DBE may be the least expensive strategy when treatment or definitive diagnosis is necessary and initial CE may be preferred when visual identification is sufficient. In settings where DBE is not available as an initial test, initial CE may be the preferred strategy.

Figure 1

Simplified model excluding complications of five competing strategies for diagnosing and managing OGIB when therapy or definitive diagnosis was intended.

Figure 2

Figure 2a. One-way sensitivity analyses. Tornado diagram for therapy or histological diagnosis as model endpoint depicts the effect on costs by varying each of the examined variables. DBE is preferred unless a threshold is identified (black line). Preference for CE occurs when cost of DBE exceeds $1,849 and PE preferred when DBE cost exceeds $2,473. CE was preferred when sensitivity of DBE was less than 68%. Only variables displaying a change in preferred strategy or that were considered clinically important parameters are depicted. DBE: double balloon enteroscopy; CE: capsule endoscopy; PE: push enteroscopy Figure 2b. Sensitivity analysis on the cost of DBE. Using a model with the goal of endoscopic therapy or definitive diagnosis, preference for DBE was sensitive to the cost of DBE. When either antegrade or retrograde DBE cost exceeded $1,849, CE became the preferred initial strategy (dotted vertical line – left). Figure 2c. Sensitivity analysis on the sensitivity of DBE. Using a model with the goal of endoscopic therapy or definitive diagnosis, preference for DBE changed to CE when DBE identified less than 68% of lesion.

Figure 3

Figure 3a. Two-way sensitivity analysis varying DBE cost and sensitivity of CE. At optimal CE performance (sensitivity > 90%), CE was preferred as long as the cost of DBE exceeded $1,650. However, CE was no longer a viable strategy once its sensitivity fell below 66%. Figure 3b. Two-way sensitivity analysis varying DBE cost and CE cost. CE was not a viable strategy whenever CE costs exceeded $875 or when the cost of DBE was less than $975. PE became viable when cost of DBE exceeded $2,000 and cost of CE exceeded $600.

Figure 4

Figure 4a. Sensitivity analysis on the cost of CE. Using a model where DBE was unavailable as an initial strategy, preference for CE was sensitive to the cost of CE. When CE cost exceeded $1,190, PE became the preferred strategy (dotted vertical line). Figure 4b. Sensitivity analysis of the proportion of lesions located proximally. Using a model where DBE was unavailable as an initial strategy, preference for CE was sensitive to the proportion of lesions located proximally, which is defined as within the reach of a PE. When the proportion of proximal lesions exceeded 64%, then PE became the preferred strategy (dotted vertical line).

Figure 5

Figure 5a. Preferred initial testing strategy when therapy or definitive diagnosis is the model endpoint. Using a Monte Carlo simulation of 100,000 trials, 77% of trials favored DBE as the initial diagnostic strategy. CE was preferred in 9% of simulated trials, while PE was preferred as the initial test in 8%. EN and SBFT accounted for 6% of total trials. Figure 5b. Preferred initial testing strategy when therapy or definitive diagnosis is the model endpoint and DBE is not available as an initial strategy. Using a Monte Carlo simulation of 100,000 trials, 45% of trials favored CE as the initial diagnostic strategy. PE was preferred in 24% of simulated trials, while EN and SBFT were preferred as the initial test in 16% and 15% of trials respectively.