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Economic Evaluation of Minimally Invasive Colectomy
Economic Evaluation of Minimally Invasive Colectomy Rabih M Salloum, MD, FACS, Debra C Bulter, CPA, MBA, Seymour I Schwartz, MD, FACS We performed a cost-benefit analysis of minimally invasive colectomy (MIC) with the appreciation that this approach extends the duration of the operation and requires additional instruments and equipment when compared with the open procedure. These negatives may be offset by decreased pain, earlier initiation of oral feeding, and a shorter hospitalization. STUDY DESIGN: We reviewed operating room records of all open colectomies (OCs) and MICs performed at Strong Memorial Hospital between January 1, 2000, and March 31, 2004, as defined by CPT codes. Operating room times, total operating room costs, lengths of hospital stay, and total hospital costs were calculated for each procedure. RESULTS: Sixty-eight right hemicolectomies (54 OCs and 14 MICs) were performed. Operating room time was significantly longer for MIC compared with OC (214 ⫾ 41 minutes versus 170 ⫾ 56 minutes, p ⫽ 0.01). Length of hospital stay was shorter for MIC compared with OC (4.5 ⫾ 1.3 days versus 7.4 ⫾ 2.5 days, p ⫽ 0.004). There were 131 left hemicolectomies (104 OCs and 27 MICs) performed. Operating room time was significantly longer for left MIC compared with left OC (256 ⫾ 46 minutes versus 213 ⫾ 60 minutes, p ⫽ 0.005). Length of hospital stay was shorter for left MIC than for left OC (4.4 ⫾ 1.3 days versus 7.9 ⫾ 3.0 days, p ⫽ 0.001). Total hospital costs were significantly lower for MIC compared with OC ($8,580 ⫾ $1,358 versus $10,303 ⫾ $3,299, p ⫽ 0.046). CONCLUSIONS: MIC is associated with a significantly longer operating room time and a shorter hospital stay than OC. Operating room cost is significantly higher for MIC, but total hospital cost is lower. MIC is cost effective and results in significant savings to the health-care system. (J Am Coll Surg 2006;202:269–274. © 2006 by the American College of Surgeons) BACKGROUND:
Minimally invasive colon (MIC) resection offers patients several advantages over the classic open colectomy (OC).1,2 Minimally invasive surgery is generally performed through smaller incisions, so is usually associated with decreased pain, improved cosmesis, and an earlier transition to oral intake.3,4 In addition, MIC allows patients to return to normal activity and productivity at an earlier stage than after an open procedure. The first reports on MIC were published in 1992;5 the procedure has been slow to gain acceptance, mainly because of its technical challenges and longer operative time. Currently, MIC appears to be gaining acceptance at a significantly slower rate than other technically less demanding
minimally invasive procedures, such as laparoscopic cholecystectomy and laparoscopic appendectomy.3,4 Although the cost effectiveness of these other minimally invasive surgical procedures has been established,3,4 the economic impact of MIC on the health-care system has not been clearly defined. Data defining the total costs of the procedure, including operating room time and charges and hospital length of stay, are scarce. It is unlikely that any multiinstitutional prospective randomized trials would be conducted to define cost effectiveness of the new procedure. We report our experience at the University of Rochester, Strong Memorial Hospital, with left and right OC and MIC performed between January 2000 and March 2004, and we provide an estimate of the cost savings to the health-care system with the introduction of MIC compared with OC.
Competing Interests Declared: None. Received June 3, 2005; Revised September 28, 2005; Accepted October 10, 2005. From the Department of Surgery, University of Rochester, Strong Memorial Hospital, Rochester, NY. Correspondence address: Rabih M Salloum, MD, FACS, University of Rochester, Department of Surgery, 601 Elmwood Ave, Box SURG, Rochester, NY 14642-8410.
© 2006 by the American College of Surgeons Published by Elsevier Inc.
METHODS Operating room records of all colectomies performed at Strong Memorial Hospital between January 1, 2000,
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Abbreviations and Acronyms
ASA MIC OC ORDB
⫽ ⫽ ⫽ ⫽
American Society of Anesthesiologists minimally invasive colectomy open colectomy Perioperative Services Operating Room Database
and March 31, 2004, were reviewed. Patients were identified based on their CPT codes (CPT # 44160 for right OC, 44140 for left OC, 44204 for laparoscopic). Operative notes on all patients were reviewed to verify the procedure code. Patients were divided into two groups—right and left colectomy—depending on the resection performed. Operating room records were reviewed to determine the duration of the operation, which was defined as the time from induction of anesthesia until dressing application. American Society of Anesthesiologists (ASA) scores were determined for each patient based on medical history at the time of the operation. Total hospital costs including the cost of supplies per patient were determined. Total length of hospital stay per patient was also obtained from the patients’ medical records and verified by the corresponding admission and discharge dates. Patients who underwent a concomitant procedure with the colectomy (eg, cholecystectomy, small bowel resection, extensive lysis of adhesions, and so on) were excluded from the analysis. The study was approved by the University of Rochester Research Subject Review Board (RSRB), and patient confidentiality was protected by deidentification of the patient data collection sheets. Data collection
Operating room and hospital costs were obtained by collecting and analyzing data retrospectively. We obtained surgical and operating room costs from the Perioperative Services Operating Room Database (ORDB). This database contains data on true costs of supplies and implants used for each surgical patient. This actual cost per patient is developed from a standard procedurebased list, which is updated throughout the case by the circulating nurse to reflect actual supply and implant use. These updated utilization lists are reviewed by the quality assurance nurse leader and are checked for accuracy as part of the case-costing control process. The true cost is then calculated by multiplying the actual case usage quantities by the current item cost contained in the master item file maintained by the Medical Center
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Purchasing Department. The cost is multiplied by a markup rate of 1.75, which has been determined as an arbitrary figure by the hospital, to calculate the patient charge. The ORDB also provides cost data for operating room time, nursing labor, ambulatory surgical center, postanesthesia care unit, anesthesia supplies, and anesthesia technician labor. Operating room time, as determined by patient in room to patient out of room and nursing labor costs are calculated from actual time recorded in the room and number of staff used. These times and staff use data are entered into an electronic perioperative documentation system, ESI (McKesson Healthcare Information Systems). ESI data are fed to the ORDB several times per day. Ambulatory surgical center, postanesthesia care unit, anesthesia supplies, and anesthesia technician labor are calculated by applying a standard charge, based on the level of service. These costs are incorporated into the total variable costs for hospital reporting. Data on the following variables are included in the hospital’s decision support system database, Trendstar (McKesson Healthcare Information Systems): patient identifier, ICD-9 principal diagnosis code, admission date, discharge date, primary payer, case mix index, total charges, net revenue, variable costs, contribution margin, fixed costs, and net margin. Fixed costs are hospital costs that stay relatively constant over a broad range of operating volume. They consist of both overhead costs and fixed direct department costs. The overhead component of fixed costs includes depreciation, heat, power, light, and hospital and medical center administration. Fixed direct department costs consist of administrative and scheduling personnel, nursing administration, and nonsalary costs such as maintenance contracts. Variable costs are the aggregate of non-ICU nursing, ICU nursing, pharmacy, laboratory services, imaging services, operating suite time and labor, operating room supplies and implants, and other ancillary services such as ambulatory surgical center costs, postanesthesia care unit, anesthesiology services, cardiology services, emergency services, and radiology services. Combining the data from the ORDB and Trendstar databases, profit and loss statements were generated for total hospital costs including the operating room components. Statistical analysis
A two-tailed Student’s t-test and Fisher’s exact test were used, as appropriate, for statistical analysis (Stata for
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Table 1. Characteristics of Study Patients Characteristic
Mean age ⫾ SD, y Men, n Women, n Diverticular disease, n Cancer, n Benign polyps, n Others,* n
Right MIC (n ⴝ 14)
Right OC (n ⴝ 54)
Left MIC (n ⴝ 27)
Left OC (n ⴝ 104)
70 ⫾ 12 7 7
70 ⫾ 15 28 26
2 12
43 4 7
57 ⫾ 16 16 11 17 2 5 3
64 ⫾ 15 51 52 59 33 2
*Volvulus, rectal prolapse, lower gastrointestinal bleeding, inflammatory bowel disease, ischemia, and nondiverticular strictures. MIC, minimally invasive colectomy; OC, open colectomy.
Windows, Stata Corporation). Data are reported as mean ⫾ standard deviation. A p value of less than 0.05 was considered statistically significant. RESULTS Characteristics of patients included in the study are shown in Table 1. Diagnoses were divided into four categories: diverticular diseases, cancer, benign polyps, and other (volvulus, rectal prolapse, lower gastrointestinal bleeding, inflammatory bowel disease, ischemia, and nondiverticular strictures). ASA scores of the patients are shown in Table 2. ASA class I (completely healthy patient) and ASA class II (patient with mild systemic disease) were reported as one group. ASA classes III and IV were reported as a group. In the MIC group, 80.5% of patients were in the ASA classes I/II and 19.5% were in the ASA class ⱖ III. In the OC group, 77.2% of patients were in the ASA classes I/II group and 22.7% were in the ASA classes III/IV (p ⬎ 0.1, Fisher’s exact test). Sixty-seven right hemicolectomy procedures (54 OCs and 13 MICs) were performed during the study period. The operating room time was longer for MIC (214 ⫾ 41 minutes versus 170 ⫾ 56 minutes, p ⫽ 0.01). Total length of stay was shorter for patients undergoing MIC Table 2. Comparison of American Society of Anesthesiologists Scores of Patients Undergoing Open Colectomy and Minimally Invasive Colectomy
Score
ASA I & II ASA III & IV Total
Open colectomy n %
122 36 155
77.2 22.8 100
Minimally invasive colectomy n %
33 8 41
80.5 19.5* 100
*p ⬎ 0.1 Fisher’s exact test. ASA, American Society of Anesthesiologists; MIC, minimally invasive colectomy; OC, open colectomy.
(4.5 ⫾ 1.3 days versus 7.4 ⫾ 2.5 days, Table 3). The results were similar when left MIC was compared with left OC (Table 3). The operations were performed by five surgeons, none of whom was fellowship trained in laparoscopic surgery. The choice of procedure was at the discretion of the operating surgeon, and the procedures were performed at variable intervals of each surgeon’s learning curve. Itemized hospital costs per patient for MIC and OC are shown in Table 4. These costs include operating room suite labor and supplies, including operating room charge time, nursing costs including intensive care unit admissions, pharmacy, and laboratory testing. Ancillary services included emergency services, cardiology services, radiology, and physical and occupational therapy. Based on this analysis, the savings per patient for MIC compared with OC are about $1,700. DISCUSSION At Strong Memorial Hospital, operating room times for OC were longer than expected but comparable to those in other published series.5,6 This increase in operating room time over that anticipated is likely because of the Table 3. Right and Left Colectomy Cost-Effectiveness Data Procedure and variables
Right MIC (n ⴝ 14)
Right colectomy cost-effectiveness data n 14 Operating room time (min)* 213 ⫾ 39 Length of stay (d) 4.5 ⫾ 1.3 Left colectomy cost-effectiveness data n 27 Operating room time (min) 256 ⫾ 46 Length of stay (d) 4.4 ⫾ 1.3
Right OC (n ⴝ 54)
p Value
54 170 ⫾ 56 7.4 ⫾ 2.5
0.01 0.004
104 213 ⫾ 60 7.9 ⫾ 3.0
0.005 0.001
Data are reported as means ⫾ standard deviation. *Operating room time was defined as the time of induction of anesthesia until the application of the dressing. MIC, minimally invasive colectomy; OC, open colectomy.
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Table 4. Comparison of Itemized Hospital Costs for Open and Minimally Invasive Colectomy Hospital costs
Fixed costs Nursing Pharmacy Laboratory Ancillary services Operating room suite labor Operating room supplies Total hospital costs
OC, $ (n ⴝ 158)
MIC, $ (n ⴝ 41)
p Value
3,783 ⫾ 1,269 3,100 ⫾ 1,219 426 ⫾ 357 256 ⫾ 351 471 ⫾ 129
2,386 ⫾ 436 1,654 ⫾ 509 164 ⫾ 111 78 ⫾ 46 360 ⫾ 86
0.007 0.005 0.003 0.018 0.016
1,333 ⫾ 416
2,272 ⫾ 781
0.029
778 ⫾ 266
1,657 ⫾ 486
0.001
8,580 ⫾ 1,358
0.046
10,303 ⫾ 3,299
Data are reported as means ⫾ standard deviation. MIC, minimally invasive colectomy; OC, open colectomy.
teaching activities taking place.6 As reported in other series,1,5,6 the learning curve for MIC was steep, but the duration of the operation decreased with time. Mainly because of the technical challenges it presents, MIC has been adopted by only a minority of institutions in the definitive treatment of benign colonic conditions such as diverticulitis, Crohn’s disease, colon polyps, and rectal prolapse.7-9 Until recently, most advocates of MIC were reluctant to recommend it as a treatment modality for colon carcinoma. Questions that had been raised about MIC being appropriate for adequate oncologic resection10,11 have been addressed in a recently published large, multicenter, noninferiority randomized trial. MIC was found to be comparable to OC for malignant disease with regard to lymph node clearance, rate of recurrence, and postoperative complications.12 So it is expected that MIC will rapidly gain more acceptance in the treatment of colorectal carcinoma. Colorectal carcinoma is the fourth most commonly diagnosed malignancy in the United States, with about 200,000 cases diagnosed per year,13 and it has a substantial impact on the health-care system. Several studies conducted outside the United States have reached conflicting conclusions regarding MIC patient cost and total cost to the health-care system. A randomized clinical trial conducted in Sweden,6 evaluated the costs of MIC compared with the open procedure. The authors reported operating room times similar to ours and similar results with respect to cost of the MIC.
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The total cost to the Swedish health-care system was similar for both procedures. One explanation of their results is the fact that the length of hospital stay was similar between the open and laparoscopic groups, and this influenced the total cost of the laparoscopic procedure. Another study from Australia2 was conducted to evaluate the relative cost of laparoscopic right hemicolectomy performed for cancer compared with open colectomy. Operating room times were similar to the ones we observed in this study, and the authors concluded that it was because of training and teaching activities. Similar to the Swedish trial, the Australian study failed to show any cost benefit for MIC, again because of the lack of difference in length of hospital stay between the two groups. A nonrandomized prospective study conducted at MD Anderson Cancer Center has also shown similar costs for open and laparoscopic colectomies.14 The study evaluated operations performed from 1992 to 1997, soon after the introduction of the procedure, and reported a significant conversion rate of 42% from laparoscopic to open colectomy. In the series reported by Taheri and colleagues,15 the introduction of MIC resulted in a significant decrease in length of hospital stay, but the authors indicated that a decrease in length of stay of 1 or 2 days had minimal impact on the overall cost of care. In our experience, the decrease in length of stay was 2.9 ⫾ 1.2 days. The operating room cost per patient was significantly higher for MIC when compared with OC, mostly because of the increase in operating room time and an increase in the use of equipment and supplies. In addition, the total hospital costs at Strong Memorial Hospital are higher than others previously reported because of the mark-up factor set by the hospital. A report by the Cleveland Clinic1 evaluated economic outcomes after laparoscopic and open colorectal surgery. The authors reported a total operating room cost of $1,784.50 (range $1,408.80 to $2,097.30) for laparoscopic and $1,021.50 (range $847.30 to $1,219.30) for open, both of which are comparable to our costs. We acknowledge several limitations of this study. This is a single institution, retrospective review in one specific geographic area. This makes generalization difficult in terms of actual costs for other institutions. The patients were not randomized and bias in patient selection, early in the study period, might have played a role in the
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decrease in length of hospital stay. There may have been a potential bias in the difficult patients being done in the OC group. Given the retrospective nature of the study, there was no mechanism in place to ascertain, a priori, the reason a surgeon elected the open rather than the laparoscopic route. MIC was not accepted as standard of care for treatment of cancer, and that may have influenced the type of procedure offered to individual patients. In this study, we did not include patients on whom a secondary procedure (eg, cholecystectomy, appendectomy, oophorectomy, and so on) was performed, so as not to bias the cost data per patient. Including these patients in our cost-benefit analysis would have further accentuated the benefit of MIC over OC. The similarity of our results to other published cost-effectiveness data lends credibility to the fact that MIC has merit in terms of minimizing costs to the health-care system. The similarity in ASA scores between the two groups is an important factor in the comparison of costs because sicker patients are likely to remain in the hospital longer because of their other comorbidities. Economically, the per-diem charges for hospital stay might be higher than actual costs, but the nursing allocations and fixed costs (which account for the bulk of the costs at the end of the patient’s hospitalization) in our hospital indicate that the differences between charges and costs are minimal (on the order of $170 per day). In summary, our results indicate that the increase in operating room time and instrumentation associated with MIC are more than offset by a significant reduction in total hospital cost consequent to a shortened hospital stay. These savings to the health-care system may be substantially greater if one were to take into account the decreased postoperative pain and earlier return to normal productive activity for patients undergoing MIC. This, coupled with improved cosmesis, provides an impetus for more widespread application of MIC.16,17 In addition, patient perception of the advantages of laparoscopic surgery may lead them to favor MIC over OC and result in increasing patient demand for MIC.17 Considering the savings per MIC patient to be about $1,700, with the estimated 120 colectomies performed at our institution each year, the savings to our health-care system are more than $200,000 per year. Author Contributions
Study conception and design: Salloum, Schwartz Acquisition of data: Salloum, Bulter
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Analysis and interpretation of data: Salloum, Bulter, Schwartz Drafting of manuscript: Salloum Critical revision: Schwartz, Salloum, Bulter Statistical expertise: Salloum Supervision: Salloum, Schwartz Acknowledgment: We acknowledge the work of Laurie Riley, Perioperative Services Information Systems Manager, and Steven Drexel, Finance Manager, Decision Support Services. Ms Riley maintains the accuracy and integrity of the ORDB and provided the surgical supply and implant cost data and case population to Mr Drexel, who developed the internal reporting process to provide comparative analysis profit and loss statements, incorporating all revenue, expense, and allocation techniques from the hospital databases. We are also grateful to Dr Katia Noyes of the University of Rochester Department of Community and Preventive Medicine for her valuable comments and suggestions on the preparation of the article.
REFERENCES 1. Delaney CP, Kiran RP, Senagore AJ, et al. Case matched comparison of clinical and financial outcome after laparoscopic or open colorectal surgery. Ann Surg 2003;238:67–72. 2. Philipson B, Bockey EL, Moore J, et al. Cost of open versus laparoscopically assisted right hemicolectomy for cancer. World J Surg 1997;21:214–217. 3. Peters JH, Ellison C, Innes JT, et al. Safety and efficacy of laparoscopic cholecystectomy: a prospective analysis of 100 initial patients. Ann Surg 1991;213:3–12. 4. Stoker ME, Vose J, O’Mara P, et al. Laparoscopic cholecystectomy; a clinical and financial analysis of 280 operations. Arch Surg 1992;127:589–594. 5. Phillips EH, Franklin M, Carroll BJ, et al. Laparoscopic colectomy. Ann Surg 1992;216:703–707. 6. Janson M, Bjorholt I, Carlsson P, et al. Randomized trial of the costs of open and laparoscopic surgery for colonic cancer. Br J Surg 2004;91:409–417. 7. Xynos E, Chrysos E, Tsiaoussis J, et al. Resection rectopexy for rectal prolapse. Surg Endosc 1999;13:862–864. 8. Young-Fadock TM, HallLong K, McConnell EJ, et al. Advantages of laparoscopic resection for ileocolic Crohn’s disease: improved outcomes and reduced costs. Surg Endosc 2001;15:450–454. 9. Young-Fadok TM, Radice E, Nelson H, et al. Benefits of laparoscopic-assisted colectomy for colon polyps: a case matched series. Mayo Clin Proc 2000;75:344–348. 10. Berends FJ, Kazemier G, Bonjer HJ, Lange JF. Subcutaneous metastases after laparoscopic colectomy. Lancet 1994;344:58. 11. Johnstone PAS, Rhode DC, Swartz SE, et al. Port site recurrences after laparoscopic and thoracoscopic procedures in malignancy. J Clin Oncol 1996;14:1950–1956.
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12. Clinical Outcomes of Surgical Therapy Study Group. A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med 2004;350:2050–2059. 13. Howe HL, Wingo PA, Thun MJ, et al. Annual report to the nation on the status of cancer featuring cancers with recent increasing trends. J Natl Cancer Inst 2001;93:824–842. 14. Bouvet M, Mansfield P, Skibber J, et al. Clinical, pathologic and economic parameters of laparosocsopic colon resection for cancer. Am J Surg 1998;176:554–558.
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15. Taheri PA, Butz DA, Greenfield LJ. Length of stay has minimal impact on the cost of hospital admission. J Am Coll Surg 2000; 191:123–130. 16. Liberman MA, Phillips EH, Carroll BJ, et al. Laparoscopic colectomy vs traditional colectomy for diverticulitis outcome and costs. Surg Endosc 1996;10:15–18. 17. Pappas TN, Jacobs DO. Laparoscopic resection for colon cancer—the end of the beginning? N Engl J Med 2004;350: 2091–2092.
Minimally invasive colon (MIC) resection offers patients several advantages over the classic open colectomy (OC).1,2 Minimally invasive surgery is generally performed through smaller incisions, so is usually associated with decreased pain, improved cosmesis, and an earlier transition to oral intake.3,4 In addition, MIC allows patients to return to normal activity and productivity at an earlier stage than after an open procedure. The first reports on MIC were published in 1992;5 the procedure has been slow to gain acceptance, mainly because of its technical challenges and longer operative time. Currently, MIC appears to be gaining acceptance at a significantly slower rate than other technically less demanding
minimally invasive procedures, such as laparoscopic cholecystectomy and laparoscopic appendectomy.3,4 Although the cost effectiveness of these other minimally invasive surgical procedures has been established,3,4 the economic impact of MIC on the health-care system has not been clearly defined. Data defining the total costs of the procedure, including operating room time and charges and hospital length of stay, are scarce. It is unlikely that any multiinstitutional prospective randomized trials would be conducted to define cost effectiveness of the new procedure. We report our experience at the University of Rochester, Strong Memorial Hospital, with left and right OC and MIC performed between January 2000 and March 2004, and we provide an estimate of the cost savings to the health-care system with the introduction of MIC compared with OC.
Competing Interests Declared: None. Received June 3, 2005; Revised September 28, 2005; Accepted October 10, 2005. From the Department of Surgery, University of Rochester, Strong Memorial Hospital, Rochester, NY. Correspondence address: Rabih M Salloum, MD, FACS, University of Rochester, Department of Surgery, 601 Elmwood Ave, Box SURG, Rochester, NY 14642-8410.
© 2006 by the American College of Surgeons Published by Elsevier Inc.
METHODS Operating room records of all colectomies performed at Strong Memorial Hospital between January 1, 2000,
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Abbreviations and Acronyms
ASA MIC OC ORDB
⫽ ⫽ ⫽ ⫽
American Society of Anesthesiologists minimally invasive colectomy open colectomy Perioperative Services Operating Room Database
and March 31, 2004, were reviewed. Patients were identified based on their CPT codes (CPT # 44160 for right OC, 44140 for left OC, 44204 for laparoscopic). Operative notes on all patients were reviewed to verify the procedure code. Patients were divided into two groups—right and left colectomy—depending on the resection performed. Operating room records were reviewed to determine the duration of the operation, which was defined as the time from induction of anesthesia until dressing application. American Society of Anesthesiologists (ASA) scores were determined for each patient based on medical history at the time of the operation. Total hospital costs including the cost of supplies per patient were determined. Total length of hospital stay per patient was also obtained from the patients’ medical records and verified by the corresponding admission and discharge dates. Patients who underwent a concomitant procedure with the colectomy (eg, cholecystectomy, small bowel resection, extensive lysis of adhesions, and so on) were excluded from the analysis. The study was approved by the University of Rochester Research Subject Review Board (RSRB), and patient confidentiality was protected by deidentification of the patient data collection sheets. Data collection
Operating room and hospital costs were obtained by collecting and analyzing data retrospectively. We obtained surgical and operating room costs from the Perioperative Services Operating Room Database (ORDB). This database contains data on true costs of supplies and implants used for each surgical patient. This actual cost per patient is developed from a standard procedurebased list, which is updated throughout the case by the circulating nurse to reflect actual supply and implant use. These updated utilization lists are reviewed by the quality assurance nurse leader and are checked for accuracy as part of the case-costing control process. The true cost is then calculated by multiplying the actual case usage quantities by the current item cost contained in the master item file maintained by the Medical Center
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Purchasing Department. The cost is multiplied by a markup rate of 1.75, which has been determined as an arbitrary figure by the hospital, to calculate the patient charge. The ORDB also provides cost data for operating room time, nursing labor, ambulatory surgical center, postanesthesia care unit, anesthesia supplies, and anesthesia technician labor. Operating room time, as determined by patient in room to patient out of room and nursing labor costs are calculated from actual time recorded in the room and number of staff used. These times and staff use data are entered into an electronic perioperative documentation system, ESI (McKesson Healthcare Information Systems). ESI data are fed to the ORDB several times per day. Ambulatory surgical center, postanesthesia care unit, anesthesia supplies, and anesthesia technician labor are calculated by applying a standard charge, based on the level of service. These costs are incorporated into the total variable costs for hospital reporting. Data on the following variables are included in the hospital’s decision support system database, Trendstar (McKesson Healthcare Information Systems): patient identifier, ICD-9 principal diagnosis code, admission date, discharge date, primary payer, case mix index, total charges, net revenue, variable costs, contribution margin, fixed costs, and net margin. Fixed costs are hospital costs that stay relatively constant over a broad range of operating volume. They consist of both overhead costs and fixed direct department costs. The overhead component of fixed costs includes depreciation, heat, power, light, and hospital and medical center administration. Fixed direct department costs consist of administrative and scheduling personnel, nursing administration, and nonsalary costs such as maintenance contracts. Variable costs are the aggregate of non-ICU nursing, ICU nursing, pharmacy, laboratory services, imaging services, operating suite time and labor, operating room supplies and implants, and other ancillary services such as ambulatory surgical center costs, postanesthesia care unit, anesthesiology services, cardiology services, emergency services, and radiology services. Combining the data from the ORDB and Trendstar databases, profit and loss statements were generated for total hospital costs including the operating room components. Statistical analysis
A two-tailed Student’s t-test and Fisher’s exact test were used, as appropriate, for statistical analysis (Stata for
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Table 1. Characteristics of Study Patients Characteristic
Mean age ⫾ SD, y Men, n Women, n Diverticular disease, n Cancer, n Benign polyps, n Others,* n
Right MIC (n ⴝ 14)
Right OC (n ⴝ 54)
Left MIC (n ⴝ 27)
Left OC (n ⴝ 104)
70 ⫾ 12 7 7
70 ⫾ 15 28 26
2 12
43 4 7
57 ⫾ 16 16 11 17 2 5 3
64 ⫾ 15 51 52 59 33 2
*Volvulus, rectal prolapse, lower gastrointestinal bleeding, inflammatory bowel disease, ischemia, and nondiverticular strictures. MIC, minimally invasive colectomy; OC, open colectomy.
Windows, Stata Corporation). Data are reported as mean ⫾ standard deviation. A p value of less than 0.05 was considered statistically significant. RESULTS Characteristics of patients included in the study are shown in Table 1. Diagnoses were divided into four categories: diverticular diseases, cancer, benign polyps, and other (volvulus, rectal prolapse, lower gastrointestinal bleeding, inflammatory bowel disease, ischemia, and nondiverticular strictures). ASA scores of the patients are shown in Table 2. ASA class I (completely healthy patient) and ASA class II (patient with mild systemic disease) were reported as one group. ASA classes III and IV were reported as a group. In the MIC group, 80.5% of patients were in the ASA classes I/II and 19.5% were in the ASA class ⱖ III. In the OC group, 77.2% of patients were in the ASA classes I/II group and 22.7% were in the ASA classes III/IV (p ⬎ 0.1, Fisher’s exact test). Sixty-seven right hemicolectomy procedures (54 OCs and 13 MICs) were performed during the study period. The operating room time was longer for MIC (214 ⫾ 41 minutes versus 170 ⫾ 56 minutes, p ⫽ 0.01). Total length of stay was shorter for patients undergoing MIC Table 2. Comparison of American Society of Anesthesiologists Scores of Patients Undergoing Open Colectomy and Minimally Invasive Colectomy
Score
ASA I & II ASA III & IV Total
Open colectomy n %
122 36 155
77.2 22.8 100
Minimally invasive colectomy n %
33 8 41
80.5 19.5* 100
*p ⬎ 0.1 Fisher’s exact test. ASA, American Society of Anesthesiologists; MIC, minimally invasive colectomy; OC, open colectomy.
(4.5 ⫾ 1.3 days versus 7.4 ⫾ 2.5 days, Table 3). The results were similar when left MIC was compared with left OC (Table 3). The operations were performed by five surgeons, none of whom was fellowship trained in laparoscopic surgery. The choice of procedure was at the discretion of the operating surgeon, and the procedures were performed at variable intervals of each surgeon’s learning curve. Itemized hospital costs per patient for MIC and OC are shown in Table 4. These costs include operating room suite labor and supplies, including operating room charge time, nursing costs including intensive care unit admissions, pharmacy, and laboratory testing. Ancillary services included emergency services, cardiology services, radiology, and physical and occupational therapy. Based on this analysis, the savings per patient for MIC compared with OC are about $1,700. DISCUSSION At Strong Memorial Hospital, operating room times for OC were longer than expected but comparable to those in other published series.5,6 This increase in operating room time over that anticipated is likely because of the Table 3. Right and Left Colectomy Cost-Effectiveness Data Procedure and variables
Right MIC (n ⴝ 14)
Right colectomy cost-effectiveness data n 14 Operating room time (min)* 213 ⫾ 39 Length of stay (d) 4.5 ⫾ 1.3 Left colectomy cost-effectiveness data n 27 Operating room time (min) 256 ⫾ 46 Length of stay (d) 4.4 ⫾ 1.3
Right OC (n ⴝ 54)
p Value
54 170 ⫾ 56 7.4 ⫾ 2.5
0.01 0.004
104 213 ⫾ 60 7.9 ⫾ 3.0
0.005 0.001
Data are reported as means ⫾ standard deviation. *Operating room time was defined as the time of induction of anesthesia until the application of the dressing. MIC, minimally invasive colectomy; OC, open colectomy.
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Table 4. Comparison of Itemized Hospital Costs for Open and Minimally Invasive Colectomy Hospital costs
Fixed costs Nursing Pharmacy Laboratory Ancillary services Operating room suite labor Operating room supplies Total hospital costs
OC, $ (n ⴝ 158)
MIC, $ (n ⴝ 41)
p Value
3,783 ⫾ 1,269 3,100 ⫾ 1,219 426 ⫾ 357 256 ⫾ 351 471 ⫾ 129
2,386 ⫾ 436 1,654 ⫾ 509 164 ⫾ 111 78 ⫾ 46 360 ⫾ 86
0.007 0.005 0.003 0.018 0.016
1,333 ⫾ 416
2,272 ⫾ 781
0.029
778 ⫾ 266
1,657 ⫾ 486
0.001
8,580 ⫾ 1,358
0.046
10,303 ⫾ 3,299
Data are reported as means ⫾ standard deviation. MIC, minimally invasive colectomy; OC, open colectomy.
teaching activities taking place.6 As reported in other series,1,5,6 the learning curve for MIC was steep, but the duration of the operation decreased with time. Mainly because of the technical challenges it presents, MIC has been adopted by only a minority of institutions in the definitive treatment of benign colonic conditions such as diverticulitis, Crohn’s disease, colon polyps, and rectal prolapse.7-9 Until recently, most advocates of MIC were reluctant to recommend it as a treatment modality for colon carcinoma. Questions that had been raised about MIC being appropriate for adequate oncologic resection10,11 have been addressed in a recently published large, multicenter, noninferiority randomized trial. MIC was found to be comparable to OC for malignant disease with regard to lymph node clearance, rate of recurrence, and postoperative complications.12 So it is expected that MIC will rapidly gain more acceptance in the treatment of colorectal carcinoma. Colorectal carcinoma is the fourth most commonly diagnosed malignancy in the United States, with about 200,000 cases diagnosed per year,13 and it has a substantial impact on the health-care system. Several studies conducted outside the United States have reached conflicting conclusions regarding MIC patient cost and total cost to the health-care system. A randomized clinical trial conducted in Sweden,6 evaluated the costs of MIC compared with the open procedure. The authors reported operating room times similar to ours and similar results with respect to cost of the MIC.
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The total cost to the Swedish health-care system was similar for both procedures. One explanation of their results is the fact that the length of hospital stay was similar between the open and laparoscopic groups, and this influenced the total cost of the laparoscopic procedure. Another study from Australia2 was conducted to evaluate the relative cost of laparoscopic right hemicolectomy performed for cancer compared with open colectomy. Operating room times were similar to the ones we observed in this study, and the authors concluded that it was because of training and teaching activities. Similar to the Swedish trial, the Australian study failed to show any cost benefit for MIC, again because of the lack of difference in length of hospital stay between the two groups. A nonrandomized prospective study conducted at MD Anderson Cancer Center has also shown similar costs for open and laparoscopic colectomies.14 The study evaluated operations performed from 1992 to 1997, soon after the introduction of the procedure, and reported a significant conversion rate of 42% from laparoscopic to open colectomy. In the series reported by Taheri and colleagues,15 the introduction of MIC resulted in a significant decrease in length of hospital stay, but the authors indicated that a decrease in length of stay of 1 or 2 days had minimal impact on the overall cost of care. In our experience, the decrease in length of stay was 2.9 ⫾ 1.2 days. The operating room cost per patient was significantly higher for MIC when compared with OC, mostly because of the increase in operating room time and an increase in the use of equipment and supplies. In addition, the total hospital costs at Strong Memorial Hospital are higher than others previously reported because of the mark-up factor set by the hospital. A report by the Cleveland Clinic1 evaluated economic outcomes after laparoscopic and open colorectal surgery. The authors reported a total operating room cost of $1,784.50 (range $1,408.80 to $2,097.30) for laparoscopic and $1,021.50 (range $847.30 to $1,219.30) for open, both of which are comparable to our costs. We acknowledge several limitations of this study. This is a single institution, retrospective review in one specific geographic area. This makes generalization difficult in terms of actual costs for other institutions. The patients were not randomized and bias in patient selection, early in the study period, might have played a role in the
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decrease in length of hospital stay. There may have been a potential bias in the difficult patients being done in the OC group. Given the retrospective nature of the study, there was no mechanism in place to ascertain, a priori, the reason a surgeon elected the open rather than the laparoscopic route. MIC was not accepted as standard of care for treatment of cancer, and that may have influenced the type of procedure offered to individual patients. In this study, we did not include patients on whom a secondary procedure (eg, cholecystectomy, appendectomy, oophorectomy, and so on) was performed, so as not to bias the cost data per patient. Including these patients in our cost-benefit analysis would have further accentuated the benefit of MIC over OC. The similarity of our results to other published cost-effectiveness data lends credibility to the fact that MIC has merit in terms of minimizing costs to the health-care system. The similarity in ASA scores between the two groups is an important factor in the comparison of costs because sicker patients are likely to remain in the hospital longer because of their other comorbidities. Economically, the per-diem charges for hospital stay might be higher than actual costs, but the nursing allocations and fixed costs (which account for the bulk of the costs at the end of the patient’s hospitalization) in our hospital indicate that the differences between charges and costs are minimal (on the order of $170 per day). In summary, our results indicate that the increase in operating room time and instrumentation associated with MIC are more than offset by a significant reduction in total hospital cost consequent to a shortened hospital stay. These savings to the health-care system may be substantially greater if one were to take into account the decreased postoperative pain and earlier return to normal productive activity for patients undergoing MIC. This, coupled with improved cosmesis, provides an impetus for more widespread application of MIC.16,17 In addition, patient perception of the advantages of laparoscopic surgery may lead them to favor MIC over OC and result in increasing patient demand for MIC.17 Considering the savings per MIC patient to be about $1,700, with the estimated 120 colectomies performed at our institution each year, the savings to our health-care system are more than $200,000 per year. Author Contributions
Study conception and design: Salloum, Schwartz Acquisition of data: Salloum, Bulter
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Analysis and interpretation of data: Salloum, Bulter, Schwartz Drafting of manuscript: Salloum Critical revision: Schwartz, Salloum, Bulter Statistical expertise: Salloum Supervision: Salloum, Schwartz Acknowledgment: We acknowledge the work of Laurie Riley, Perioperative Services Information Systems Manager, and Steven Drexel, Finance Manager, Decision Support Services. Ms Riley maintains the accuracy and integrity of the ORDB and provided the surgical supply and implant cost data and case population to Mr Drexel, who developed the internal reporting process to provide comparative analysis profit and loss statements, incorporating all revenue, expense, and allocation techniques from the hospital databases. We are also grateful to Dr Katia Noyes of the University of Rochester Department of Community and Preventive Medicine for her valuable comments and suggestions on the preparation of the article.
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