Using Delta/DRG Diagrams and Decision Tree Analysis to Select a Cost-Effective Surgery for Cholecystitis

BACKGROUND AND OBJECTIVES Many studies have attempted cost analysis of laparoscopic cholecystectomy as compared to open cholecystectomy. However, these analyses have included costs, charges, expenses, etc., and at times they have been used interchangeably. This paper demonstrates how DRG diagrams containing charges and length-of-stay, preoperative prediction of conversion rates, decision-tree construction and sensitivity analysis can be used to select the most cost-efficient operation for a given patient with cholecystitis. METHODS A Delta DRG analysis for complicated cholecystectomy (DRG 195) showed the hospital to be an extreme outlier in both charges and length of stay. Record review indicated that 55% of the cases were converted laparoscopic cholecystectomies and the remainder were aged or younger patients with advanced disease. Chart and literature review determined the causes and the probability of conversion. Data were then placed into decision-tree and sensitivity analyses. The most cost-effective operation for a given probability of conversion was demonstrated. RESULTS Three preoperative findings and combinations of each predicted conversion rates and analysis showed that the charge of laparoscopic cholecystectomy must be held below the range of $5,361-$13,084 to make routine laparoscopic cholecystectomy cost-effective. CONCLUSIONS This method demonstrated that using Delta/DRG, decision-tree and sensitivity analysis offers physicians, hospitals and other health-care providers a method of evaluating the treatment of DRG categories to determine the most cost-effective management.