Management of Obscure Occult Gastrointestinal Bleeding: A Cost-Minimization Analysis  Ma Somsouk, Ian M. Gralnek, John M. Inadomi  Clinical Gastroenterology and Hepatology  Volume 6, Issue 6, Pages 661-670 (June 2008) DOI: 10.1016/j.cgh.2008.02.033 Copyright © 2008 AGA Institute Terms and Conditions

Figure 1 Simplified model excluding complications of 5 competing strategies for diagnosing and managing OGIB when therapy or definitive diagnosis was intended. Clinical Gastroenterology and Hepatology 2008 6, 661-670DOI: (10.1016/j.cgh.2008.02.033) Copyright © 2008 AGA Institute Terms and Conditions

Figure 2 One-way sensitivity analyses. Tornado diagram for therapy or histologic diagnosis as model end point 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 $1849 and PE is preferred when DBE cost exceeds $2473. CE was preferred when the sensitivity of DBE was less than 68%. Only variables displaying a change in preferred strategy or that were considered clinically important parameters are depicted. (B) Sensitivity analysis on the cost of DBE. By 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 $1849, CE became the preferred initial strategy (dotted vertical line, left). (C) Sensitivity analysis on the sensitivity of DBE. By 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. Clinical Gastroenterology and Hepatology 2008 6, 661-670DOI: (10.1016/j.cgh.2008.02.033) Copyright © 2008 AGA Institute Terms and Conditions

Figure 3 (A) 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 $1650. However, CE was no longer a viable strategy once its sensitivity decreased to less than 66%. (B) 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 the cost of DBE exceeded $2000 and the cost of CE exceeded $600. Clinical Gastroenterology and Hepatology 2008 6, 661-670DOI: (10.1016/j.cgh.2008.02.033) Copyright © 2008 AGA Institute Terms and Conditions

Figure 4 (A) Preferred initial testing strategy when therapy or definitive diagnosis is the model end point. By 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, whereas PE was preferred as the initial test in 8%. EN and SBFT accounted for 6% of total trials. (B) Preferred initial testing strategy when therapy or definitive diagnosis is the model end point and DBE is not available as an initial strategy. By 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, whereas EN and SBFT were preferred as the initial tests in 16% and 15% of trials, respectively. Clinical Gastroenterology and Hepatology 2008 6, 661-670DOI: (10.1016/j.cgh.2008.02.033) Copyright © 2008 AGA Institute Terms and Conditions

Figure 5 (A) Sensitivity analysis on the cost of CE. By using a model in which DBE was unavailable as an initial strategy, preference for CE was sensitive to the cost of CE. When CE cost exceeded $1190, PE became the preferred strategy (dotted vertical line). (B) Sensitivity analysis of the proportion of lesions located proximally. By using a model in which 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). Clinical Gastroenterology and Hepatology 2008 6, 661-670DOI: (10.1016/j.cgh.2008.02.033) Copyright © 2008 AGA Institute Terms and Conditions