Figure 3. Sensitivity analysis for conversion rates of 20%. found the overall mortality rate had been reduced by 33%. However, the total number of cholecystectomy-related deaths had not fallen because of a 28% increase in the rate of cholecystectomies.4 This study and the NIH Consensus Conference support the value of laparoscopic cholecystec- tomy. Now that the technique has proven to be beneficial, the current challenge to all health providers is to improve these results by further reducing mortality and morbidity, while improving cost-efficiency. To achieve this, databases for cholecystectomies must be studied to determine which aspects of the preoperative evaluation, surgery and post- operative treatment could be modified to achieve these goals. This paper attempts to address these goals with studying the charges for open, laparoscopic and converted laparoscopic cholecystectomy by evaluating matched pairs of patients in a large data set. Matched-pair comparisons of open and converted laparo- scopic cholecystectomy provide a simple method of deter- mining the true charges for laparoscopic cholecystectomy (including increased operative time, anesthesia time, cholangiograms, instruments, etc.). With similar length-of- stay (LOS), and averaging the charges over a large number of matched pairs, the main independent variable remaining is that of the charge for the laparoscopy. In this comparative series, that charge equaled $6,880 ($19,922 - $13,042). Reduction of this charge by applying reusable instruments and having surgeons with advanced laparoscopic skills operate on patients that have a higher probability of conversion would make laparoscopic chole- cystectomy more cost-effective. Consider that the average charge for laparoscopic chole- cystectomy in the 633 patients equaled $16,011 and the average charge for open cholecystectomy was $13,042. A decision-tree analysis of these values shows that managed- care contractors would prefer open cholecystectomy for all patients with cholecystitis at MMC(Figure 1). However, most patients would not enroll in a health plan or go to a hospital which did not provide laparoscopic cholecystec- tomy, so an evaluation of what could be done to reduce the charges for laparoscopic cholecystectomy must be done to make laparoscopic cholecystectomy attractive to the buyer. The most important question is, "How much of a reduction in charge (cost) would be necessary to make laparoscopic cholecystectomy cost-efficient?" This depends not only on a reduction in charges but on the per- centage of conversions (because of the high cost of con- versions). Sensitivity analysis of these data shows that if the conversion rate equals 5%, a charge of < $12,679.90 would be needed to make laparoscopic cholecystectomy cost-effective (Figure 2). Therefore, a $3,331 ($16,011 - $12,680) reduction in the charge of laparoscopic cholecys- tectomy would be needed before all patients could be con- sidered for laparoscopic cholecystectomy. If the conversion rate equals 20%, then a charge of < $11,322 would be necessary to develop cost-efficiency (Figure 3). Therefore, a $4,689 ($16,011 - $11,322) reduc- tion would be needed to consider all patients for laparo- scopic cholecystectomy. Therefore, the greater the amount of reduction needed, the less likely efficiency can be achieved by reducing laparoscopic cholecystectomy charges. Vanek and Borguet reviewed the cost of laparoscopic ver- sus open cholecystectomy in a community hospital.5 They demonstrated that conversion from laparoscopic to open cholecystectomy resulted in a 57% increase in total charges over laparoscopic cholecystectomy. They suggested that this is due to the increase in hospital LOS of 4.7 days. They further demonstrated a charge for open cholecystec- tomy of $8,160 versus $10,210 (p<0.001) for laparoscopic cholecystectomy. Furthermore, the mean total hospital charge for converted laparoscopic cholecystectomies was $16,070. Given the literature average of return to work of 8.4 days for laparoscopic cholecystectomy and 27.5 days for open cholecystectomy, a savings of $2,483 accrues with the selection of laparoscopic cholecystectomy. Comparative analysis is difficult because many of these studies include all cholecystectomy categories while other studies were limited to elective laparoscopic cholecystec- tomy patients. Furthermore, these studies reflect marked geographical and socioeconomic factors as well as severi- ty of disease mixes. It therefore becomes advisable that JSLS (1997)1:285-288 287