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The Optimal Utilization of EUS in Pancreatic Cancer Staging
*S1604 Cost-effectiveness of Capsule Endoscopy in Diagnosing Obscure Gastrointestinal Bleeding: An International Comparison Elvira Mueller, Bjoern Schwander, Rito Bergemann PURPOSE: To analyze the cost-effectiveness of capsule endoscopy (CE) in diagnosing obscure gastrointestinal bleeding from a health care payer perspective in the United States, France, the United Kingdom, Switzerland and Germany. METHODS: Based on clinical trial data and more than 20 publications available through December 1, 2003, a microsimulation model incorporating first- and second-order Monte Carlo simulation was developed. The model calculates the costs per correctly diagnosed case in patients with obscure gastrointestinal bleeding. Sensitivity and specificity values for CE and the comparator push enteroscopy (PE) as well as kind and number of other procedures performed prior to diagnosis were evaluated from 7 controlled clinical trials (n=184) and confirmed by published data. Procedure cost, the cost of diagnostic failure (false positive and false negative diagnosis) are considered and incremental costeffectiveness ratios dependent on disease prevalence are given. Cost data were estimated from a healthcare payer perspective using the Medicare fee schedule (United States), Assurance Maladie fee schedule (France), NHS Reference Cost (UK), EBM fee schedule (Germany), and the TARMED fee schedule (Switzerland). All costs refer to 2003 EURO. RESULTS: Sensitivity for CE was 89-99% and 27-60% for PE. Specificity values were 90-99% for CE and 50-70% for PE respectively. In all five countries CE was cost saving, i.e. more effective and less costly compared to push enteroscopy, when the prevalence of the disease was 30% or higher. Most common use for CE is at a prevalence of 50%. Cost savings at a prevalence of 50% are for example 517 EUR (Germany), 1004 EUR (US) and 2240 EUR (Switzerland). Probabilistic sensitivity analyses approved a high robustness for these results. CONCLUSIONS: CE proved to have a higher effectiveness than its comparator when diagnosing obscure bleeding. Though procedure costs vary substantially from country to country incremental analysis shows that the use of CE has a cost-saving potential in all five countries. From a health-economic perspective the use of capsule endoscopy is recommended in the work-up of patients with obscure gastrointestinal bleeding after upper and lower GI endoscopy.
*S1606 Economic Evaluation of Wireless Capsule Endoscopy in Diagnosing Crohn's Disease Neil I. Goldfarb, Laura Pizzi, Christopher Salvador, Vanja Sikirica, Joseph P. Fuhr Jr. Purpose: To develop a decision tree model for economic evaluation of wireless capsule endoscopy (WCE) in comparison with diagnostic tests for Crohn’s Disease in the small bowel. Methods: Published literature, clinical trial data, and input from clinical experts served as data sources for: 1) construction of a cause and effect diagram depicting contributors to the costs of diagnosis and treatment; 2) exploration of where WCE should be placed within the diagnostic algorithm for Crohn’s; and, 3) construction of decision tree models with sensitivity analyses to explore diagnostic costs using WCE versus other tests. Decision tree models, taking a payor perspective, were based on published diagnostic yields of procedures, and average Medicare charges. Results: Literature review confirms that Crohn’s Disease is a significant and growing health concern from clinical, humanistic, and economic perspectives. Approximately 70% of Crohn’s cases have evidence of disease in the small bowel, and 30% of cases are limited to the small bowel. Diagnostic costs for Crohn’s Disease can be considerable, especially given the cycle of repeat testing associated with low diagnostic yield of certain tests and inability of current diagnostic tests to image the entire small bowel. WCE has a higher diagnostic yield than other procedures, especially due to ability to image the entire small bowel and provide clearer imaging, and is more acceptable to patients. A decision tree model comparing 2 arms – SBFT, followed by either enteroclysis or WCE – demonstrates that 12% of cases undergoing SBFT and WCE would remain undiagnosed compared to 26% of cases undergoing SBFT and enteroclysis. WCE produces cost savings if the cost of additional diagnostic testing for these undiagnosed groups is assumed to be as low as $1,500. For example, if the cost of additional work-up for undiagnosed cases was $2,200 (a figured supported by literature review), the SBFT/ enteroclysis expected average diagnostic cost would be $865, compared to $760 for SBFT/WCE. Conclusion: A diagnostic algorithm employing WCE after SBFT would most likely be less costly, from a payer perspective, than current diagnostic practice. WCE also could reduce diagnostic costs significantly if used as the first line diagnostic test in cases where strictures were not suspected, obviating the need for a prior SBFT.
*S1605 The Optimal Utilization of EUS in Pancreatic Cancer Staging Ali A. Siddiqui, William M. Tierney Background: The optimal utilization of EUS for pancreatic cancer staging remains undefined. A previously published decision model found EUS was cost-effective. We designed a decision model to determine the impact of alternative staging strategies using helical CT(HCT) and EUS with emphasis on limiting negative outcomes. Recent ASGE guidelines imply EUS is particularly important for patients with high surgical risks. We examined the impact of expected surgical mortality on outcomes from alternative staging strategies. Methods: Patients entered the model with obstructive jaundice due to a pancreatic mass. Four strategies were examined. HCT-alone: used HCT as the only test to determine vascular invasion (VI). Low threshold for surgery (Low-thresh): required both HCT and EUS demonstrate VI before tumor deemed unresectable. High threshold for surgery (High-thresh): required either HCT or EUS demonstrate VI. All-EUS: all patients have HCT and EUS regardless of whether HCT demonstrates VI and tumor deemed unresectable only if EUS shows VI. Variables were determined from published literature and direct costs were based on average actual reimbursements. Baseline assumptions included: EUS sens for VI 75%, specificity 71%; HCT sens for VI 75%, specificity 90%; operative mortality 2%. Optimal outcome was curative resection. Negative outcomes were surgical mortality and resectable tumor denied surgery. Sensitivity analysis was performed. Results: Low-thresh resulted in the most curative resections and least negative outcomes. This remained the dominant strategy even when operative mortality was 20% and/ or the sensitivity and specificity of EUS were both 90%. Low-Thresh and HCTalone had similar economic outcomes. All-EUS and High-thresh are inferior strategies based on lower cure rates, higher cost, and more resectable tumors denied cure. Conclusion: Using EUS in all patients or deeming a tumor unresectable when either HCT or EUS demonstrates VI results in suboptimal clinical outcomes. Similarly, relying on HCT as the only means to assess VI compromises the number of curative resections. Selective use of EUS to confirm VI demonstrated on HCT is the preferred strategy in patients with both low and high surgical risks.
P138
GASTROINTESTINAL ENDOSCOPY
*S1607 A Cost-Minimization Analysis of Alternative Strategies in Diagnosing Pancreatic Cancer Victor K. Chen, Miguel R. Arguedas, Meredith L. Kilgore, Mohamad A. Eloubeidi Background: Tissue confirmation for suspected pancreatic cancer is required prior to therapy. There is a paucity of cost-minimization studies comparing biopsy modalities in these patients. We, therefore, compared alternative strategies to better define their role in diagnosing suspected pancreatic cancer. Methods: A decision analysis model of patients with suspected pancreatic cancer was constructed utilizing DATA 3.5 (TreeAge, Williamstown, MA). We compared costs, failure rate, testing characteristics and complications. The strategies evaluated included: 1) CT/US-FNA, 2) ERCP-Brushings, 3) EUS-FNA and 4) surgical biopsy. If initial modality confirmed cancer, further analysis ceased. However, if first attempt failed, alternatives were analyzed to find the preferable secondary biopsy method. Outcome measures were total costs and effectiveness at diagnosis. Results: CT/US-FNA and ERCP-B showed comparable costs to EUSFNA, but resulted in lower yields for cytological confirmation. Surgery displayed higher diagnostic efficiency to EUS-FNA, but at higher complication rates (15% vs. 2%) and costs expenditures. Cost-minimization decision analysis resulted in EUS-FNA as being the preferred modality for diagnosis of suspected pancreatic cancer. Resultant expected costs and strategies in decreasing favorability included: 1) EUS-FNA ($1,405), 2) ERCP-B ($1,432), 3) CT/US-FNA ($3,682) and 4) surgery ($17,711). Additional analysis showed EUS-FNA as the preferred secondary modality after an alternative method failed. One and two-way sensitivity analysis confirmed findings within a robust range. Conclusions: EUSFNA was the best initial and the preferred secondary alternative method for the diagnosis of suspected pancreatic cancer. Local expertise and availability should be considered when choosing an optimal biopsy strategy.
VOLUME 59, NO. 5, 2004
*S1606 Economic Evaluation of Wireless Capsule Endoscopy in Diagnosing Crohn's Disease Neil I. Goldfarb, Laura Pizzi, Christopher Salvador, Vanja Sikirica, Joseph P. Fuhr Jr. Purpose: To develop a decision tree model for economic evaluation of wireless capsule endoscopy (WCE) in comparison with diagnostic tests for Crohn’s Disease in the small bowel. Methods: Published literature, clinical trial data, and input from clinical experts served as data sources for: 1) construction of a cause and effect diagram depicting contributors to the costs of diagnosis and treatment; 2) exploration of where WCE should be placed within the diagnostic algorithm for Crohn’s; and, 3) construction of decision tree models with sensitivity analyses to explore diagnostic costs using WCE versus other tests. Decision tree models, taking a payor perspective, were based on published diagnostic yields of procedures, and average Medicare charges. Results: Literature review confirms that Crohn’s Disease is a significant and growing health concern from clinical, humanistic, and economic perspectives. Approximately 70% of Crohn’s cases have evidence of disease in the small bowel, and 30% of cases are limited to the small bowel. Diagnostic costs for Crohn’s Disease can be considerable, especially given the cycle of repeat testing associated with low diagnostic yield of certain tests and inability of current diagnostic tests to image the entire small bowel. WCE has a higher diagnostic yield than other procedures, especially due to ability to image the entire small bowel and provide clearer imaging, and is more acceptable to patients. A decision tree model comparing 2 arms – SBFT, followed by either enteroclysis or WCE – demonstrates that 12% of cases undergoing SBFT and WCE would remain undiagnosed compared to 26% of cases undergoing SBFT and enteroclysis. WCE produces cost savings if the cost of additional diagnostic testing for these undiagnosed groups is assumed to be as low as $1,500. For example, if the cost of additional work-up for undiagnosed cases was $2,200 (a figured supported by literature review), the SBFT/ enteroclysis expected average diagnostic cost would be $865, compared to $760 for SBFT/WCE. Conclusion: A diagnostic algorithm employing WCE after SBFT would most likely be less costly, from a payer perspective, than current diagnostic practice. WCE also could reduce diagnostic costs significantly if used as the first line diagnostic test in cases where strictures were not suspected, obviating the need for a prior SBFT.
*S1605 The Optimal Utilization of EUS in Pancreatic Cancer Staging Ali A. Siddiqui, William M. Tierney Background: The optimal utilization of EUS for pancreatic cancer staging remains undefined. A previously published decision model found EUS was cost-effective. We designed a decision model to determine the impact of alternative staging strategies using helical CT(HCT) and EUS with emphasis on limiting negative outcomes. Recent ASGE guidelines imply EUS is particularly important for patients with high surgical risks. We examined the impact of expected surgical mortality on outcomes from alternative staging strategies. Methods: Patients entered the model with obstructive jaundice due to a pancreatic mass. Four strategies were examined. HCT-alone: used HCT as the only test to determine vascular invasion (VI). Low threshold for surgery (Low-thresh): required both HCT and EUS demonstrate VI before tumor deemed unresectable. High threshold for surgery (High-thresh): required either HCT or EUS demonstrate VI. All-EUS: all patients have HCT and EUS regardless of whether HCT demonstrates VI and tumor deemed unresectable only if EUS shows VI. Variables were determined from published literature and direct costs were based on average actual reimbursements. Baseline assumptions included: EUS sens for VI 75%, specificity 71%; HCT sens for VI 75%, specificity 90%; operative mortality 2%. Optimal outcome was curative resection. Negative outcomes were surgical mortality and resectable tumor denied surgery. Sensitivity analysis was performed. Results: Low-thresh resulted in the most curative resections and least negative outcomes. This remained the dominant strategy even when operative mortality was 20% and/ or the sensitivity and specificity of EUS were both 90%. Low-Thresh and HCTalone had similar economic outcomes. All-EUS and High-thresh are inferior strategies based on lower cure rates, higher cost, and more resectable tumors denied cure. Conclusion: Using EUS in all patients or deeming a tumor unresectable when either HCT or EUS demonstrates VI results in suboptimal clinical outcomes. Similarly, relying on HCT as the only means to assess VI compromises the number of curative resections. Selective use of EUS to confirm VI demonstrated on HCT is the preferred strategy in patients with both low and high surgical risks.
P138
GASTROINTESTINAL ENDOSCOPY
*S1607 A Cost-Minimization Analysis of Alternative Strategies in Diagnosing Pancreatic Cancer Victor K. Chen, Miguel R. Arguedas, Meredith L. Kilgore, Mohamad A. Eloubeidi Background: Tissue confirmation for suspected pancreatic cancer is required prior to therapy. There is a paucity of cost-minimization studies comparing biopsy modalities in these patients. We, therefore, compared alternative strategies to better define their role in diagnosing suspected pancreatic cancer. Methods: A decision analysis model of patients with suspected pancreatic cancer was constructed utilizing DATA 3.5 (TreeAge, Williamstown, MA). We compared costs, failure rate, testing characteristics and complications. The strategies evaluated included: 1) CT/US-FNA, 2) ERCP-Brushings, 3) EUS-FNA and 4) surgical biopsy. If initial modality confirmed cancer, further analysis ceased. However, if first attempt failed, alternatives were analyzed to find the preferable secondary biopsy method. Outcome measures were total costs and effectiveness at diagnosis. Results: CT/US-FNA and ERCP-B showed comparable costs to EUSFNA, but resulted in lower yields for cytological confirmation. Surgery displayed higher diagnostic efficiency to EUS-FNA, but at higher complication rates (15% vs. 2%) and costs expenditures. Cost-minimization decision analysis resulted in EUS-FNA as being the preferred modality for diagnosis of suspected pancreatic cancer. Resultant expected costs and strategies in decreasing favorability included: 1) EUS-FNA ($1,405), 2) ERCP-B ($1,432), 3) CT/US-FNA ($3,682) and 4) surgery ($17,711). Additional analysis showed EUS-FNA as the preferred secondary modality after an alternative method failed. One and two-way sensitivity analysis confirmed findings within a robust range. Conclusions: EUSFNA was the best initial and the preferred secondary alternative method for the diagnosis of suspected pancreatic cancer. Local expertise and availability should be considered when choosing an optimal biopsy strategy.
VOLUME 59, NO. 5, 2004