Original Paper Received: October 27, 2014 Accepted after revision: December 31, 2014 Published online: March 18, 2015
Dig Surg 2015;32:150–156 DOI: 10.1159/000371861
Hospital Cost-Analysis of Complications after Major Abdominal Surgery Jennifer Straatman a Miguel A. Cuesta a Elly S.M. de Lange-de Klerk b Donald L. van der Peet a
a Department of Gastrointestinal Surgery, VU Medical Centre and b Department of Epidemiology and Biostatistics, VU Medical Centre, Amsterdam, The Netherlands
Key Words Major abdominal surgery · Postoperative complications · Cost-analysis
Abstract Background: Complications after major abdominal surgery (MAS) are associated with increased morbidity and mortality. Rising costs in health care are of increasing interest and a major factor affecting hospital costs are postoperative complications. In this study, the costs associated with complications are assessed. Methods: Retrospective cohort study of 399 consecutive patients that underwent MAS. Analysis of total costs for hospital stay, complications and treatment was performed, including bootstrapping; allowing for subtraction of data with 95% confidence intervals. Results: For a single patient who underwent MAS the average costs, adjusted for ASA-classification and surgery type, adds up to EUR 8,584.81 (95% CI EUR 8,332.51 – EUR 8,860.81) in patients without complications. EUR 15,412.96 (95% CI EUR 14,250.22 – EUR 16,708.82) after minor complications, and EUR 29,198.23 (95% CI EUR 27,187.13 – EUR 31,295.78) after major complications (p < 0.001). Conclusion: The results provide an insight into the scope of hospital costs associated with complications. Major complications occur in 20% of patients undergoing MAS and account for 50% of the total
© 2015 S. Karger AG, Basel 0253–4886/15/0322–0150$39.50/0 E-Mail [email protected] www.karger.com/dsu
costs of care. Implementation of a protocol aimed at early diagnosis and treatment of complications might lead to a decrease in morbidity and mortality, but also prove to be cost effective. © 2015 S. Karger AG, Basel
Introduction
Major abdominal surgery (MAS) may be defined as all upper gastrointestinal (UGI), hepatopancreatobilliary (HPB) and colorectal surgery (CRS) with either primary anastomosis and/or stoma. MAS is associated with an overall morbidity rate of 35%. There is a 20% rate of major complications, which require invasive treatment and intensive monitoring [1–3]. Besides intensive treatment, these complications are associated with increased morbidity, mortality, hospital stay and intensive care stay [4, 5]. In 1992, Clavien et al. established a classification system for postoperative complications with a four-level severity grading based on required intervention for complications and length of hospital stay [6]. In 2004, the classification system was reevaluated and refined by Clavien and Dindo et al.; grading is now solely based on the required intervention for complications and has been widely adopted [7, 8]. Many authors have adapted the ClavienDrs. J. Straatman Department of Gastrointestinal Surgery VU Medical Centre, De Boelelaan 1117 Room ZH 7F020, 1081 HV Amsterdam (The Netherlands) E-Mail je.straatman @ vumc.nl
Dindo classification and further divided it into minor and major complications [9]. Minor complications, consisting of grades I and II, require noninvasive treatment with medication or local drainage of an abscess at the bedside. Major complications, consisting of grades III, IV and V, require invasive treatment such as percutaneous drainage, reoperation and/or admission to an Intensive Care Unit (ICU) and might even lead up to death (grade V). Postoperative complications induce stress in patients and affect their quality of life in a significant manner. Moreover, postoperative complications lead to an increased consumption of resources [10]. As part of rising costs in health care, we regard postoperative complications to be a major factor affecting hospital costs. There are insufficient data as to the degree to which complications increase these costs. Hence, the aim of this study is to assess how high the overall costs of postoperative complications are and how this impacts the budget of a surgical department.
Materials and Methods Patient Data Retrospective review of data of patients that underwent Major Abdominal Surgery, defined as all UGI, HPB and CRS resections with either primary anastomosis and/or creation of stoma, in 2009 and 2010 in the Vrije Universiteit Medical Center (VUMC), Amsterdam, the Netherlands. Data on laparoscopic and open procedures, acute and elective procedures and malignant and benign disease were included. Patients younger than 18 years of age were excluded. All patients received perioperatively prophylactic intravenous antibiotics and thromboprophylaxis according to local protocol. Data was recorded with regard to patient data: age, gender, height, weight, medical history, comorbidity and the American Society of Anaesthesiologists (ASA)-classification. Surgical data consisted of indication and type of operation, duration and perioperative blood loss. Postoperative parameters included recording of complications according to Clavien-Dindo classification up to 90 days postoperatively, additional imaging and laboratory tests for diagnosis of complications, intensive care admission, interventional radiology performed, reoperations, hospital admission duration, readmission and mortality.
If a major complication was diagnosed, treatment was initiated immediately and, if necessary, the patient was admitted to the ICU. Interventions usually consisted of percutaneous drainage or relaparotomy. Cost Analysis Cost analysis was considered from a hospital perspective and therefore only hospital costs related to major abdominal surgery were included. Our main objective was to determine the difference in costs between patients following an uncomplicated, minor or major complicated postoperative course. Hence, only those variables for which a difference in costs per course was considered possible and relevant were included. Information on prices of resources was provided by the information and cost management department of the VU University Medical Centre Amsterdam, the Netherlands and by the Dutch health care standards of 2010 [11]. Relevant Costs Costs concerning a complicated postoperative course included the differences in hospital stay, (including length of hospital stay upon re-admission) and ICU stay; costs for diagnostic tests such as laboratory tests and CT scans and costs for reoperation or percutaneous drainage. C-reactive protein (CRP) levels, white blood cell count (WBC) and hemoglobin were assessed. Laboratory parameters were available up to 14 days postoperatively; therefore, costs concerning laboratory tests may be underestimated. Other laboratory parameters are considered beyond the scope of this study. CT-scan imaging is considered the modality of choice in diagnosis of major complications after major abdominal surgery and included in the cost analysis. Other imaging modalities such as plain X-rays and ultrasonography, used less frequently, are not considered in this study. Costs for reoperation were calculated by multiplying operative time by a cost price per minute. Average operative costs consisted of operating room costs and the salaries for personnel (two nurses, one gastrointestinal surgeon, assistant, one anesthesiologist and one anesthesiology nurse) in the operating room. The cost of separate items was provided by the VUMC and it was estimated that the average cost per hour of an operation was EUR 1,020 per hour (EUR 17 per minute). Intervention radiology costs were calculated including the assessment of CT-scan imaging by a radiologist, and placement of drain by a radiologist, including consumables, and was estimated at EUR 424.21. Data regarding off-hour surgery was not available. An overview of costs is depicted in table 2.
Complications All postoperative complications were classified as either minor, labelled by Clavien-Dindo grades I and II or major complications, consisting of grades III, IV and V [7]. Clinical deterioration (such as tachycardia, fever, failure to pass stool, vomiting, insufficient urinary production, pain and abdominal tenderness) and increase in CRP and/or leucocytes resulted in additional examinations, generally consisting of laboratory tests and a CT-scan (Computer Tomography), to diagnose complications. CT scans were performed in a Philips 256 slice Brilliance iCT scanner, with oral, rectal and intravenous contrast.
Statistical Analysis Continuous variables are presented as means and standard deviations. Student’s t-tests were used for comparison. Categorical variables are expressed as frequencies and compared with Chisquare or McNemar analysis as appropriate. A value of p < 0.05 was considered statistically significant. Baseline characteristics of the three patient groups (uncomplicated, minor and major complications) were compared. In order to correct for skewness as measured asymmetry of the probability distribution, and possible bias in cost data and to allow for an estimation of confidence intervals with deemed normality, applied bias-corrected accelerated bootstrapping techniques were used [12, 13]. With bootstrapping 2,000 new datasets are randomly resampled from the original dataset, involving replacement of data (samples can be selected multiple times in one sample) and allow-
Hospital Cost-Analysis of Complications after Major Abdominal Surgery
Dig Surg 2015;32:150–156 DOI: 10.1159/000371861
151
Table 1. Baseline characteristics of patients with an uncomplicated, minor or major complicated postoperative course
Parameter
Uncomplicated
Patients, n (%) Gender, n (%) Male Female Age, years (mean ± SD) ASA score (mean ± SD) Body mass index (BMI), kg/m2 (mean ± SD) Operation type, n (%) Upper GI HPB Lower GI Indication, n (%) Elective Acute Malignant Benign Epidural anesthesia, n (%) Operation Access, n (%) Laparotomy Laparoscopy Conversion Anastomosis, n (%) Ostomy, n (%) Protective ostomy Drain, n (%) Duration of surgery, min ± SD Perioperative blood loss, ml ± SD Hospital stay, days ± SD Intensive care stay Mortality
Minor complication
Major complication
Total
p value
258 (64.7)
59 (14.8)
83 (20.6)
399
148 (57.6) 109 (42.2) 58.7±15.6 1.1±0.6
38 (64.4) 21 (35.6) 66.2±15 1±0.6
49 (59) 34 (20.7) 60.4±14.7 1.3±0.8
235 (58.9) 164 (41.1) 60.2±15.5 1.1±0.7
0.639 0.003 0.005
25.3±5.7
24.9±4.3
24.9±4.7
25.1±5.3
0.832
0.002
35 (47.3) 69 (75.8) 153 (65.4)
13 (17.6) 10 (11) 36 (15.4)
26 (35.1) 12 (13.2) 45 (19.2)
74 (18.5) 92 (22.8) 234 (58.6)
215 (65.5) 42 (59.2) 174 (68) 82 (32) 153 (66.2)
48 (14.6) 11 (15.5) 43 (74.1) 15 (25.9) 29 (12.6)
65 (19.8) 18 (25.4) 55 (66.3) 28 (33.7) 49 (21.2)
328 (82.2) 71 (17.8) 274 (68.7) 125 (31.3) 231 (57.9)
0.63 0.221
155 (60.3) 90 (35) 12 (4.7) 154 (60.2) 47 (43.6) 17 (63) 102 (54.8) 210.3±150 199.4±333 9.7±5.1 2.7±3 0
36 (61) 17 (28.8) 6 (10.2) 43 (16.8) 14 (17.5) 6 (22.2) 28 (15.1) 226.3±91 291.9±452 17.8±15.2 10.2±19.2 0
57 (68.7) 22 (26.5) 4 (18.2) 59 (23) 19 (23.8) 4 (14.8) 56 (30.1) 234.1±95 611.2±951 35±36.7 17±22.3 14 (3.5)
248 (62.2) 129 (28.6) 22 (4.8) 256 (64.2) 80 (20.1) 27 (6.8) 186 (46.6) 217.6±132.7 295.7±554 16.1±20.7 11.3±18.8 14 (3.5)
0.368 0.058 0.341 0.12
Dig Surg 2015;32:150–156 DOI: 10.1159/000371861
Hospital Cost-Analysis of Complications after Major Abdominal Surgery Jennifer Straatman a Miguel A. Cuesta a Elly S.M. de Lange-de Klerk b Donald L. van der Peet a
a Department of Gastrointestinal Surgery, VU Medical Centre and b Department of Epidemiology and Biostatistics, VU Medical Centre, Amsterdam, The Netherlands
Key Words Major abdominal surgery · Postoperative complications · Cost-analysis
Abstract Background: Complications after major abdominal surgery (MAS) are associated with increased morbidity and mortality. Rising costs in health care are of increasing interest and a major factor affecting hospital costs are postoperative complications. In this study, the costs associated with complications are assessed. Methods: Retrospective cohort study of 399 consecutive patients that underwent MAS. Analysis of total costs for hospital stay, complications and treatment was performed, including bootstrapping; allowing for subtraction of data with 95% confidence intervals. Results: For a single patient who underwent MAS the average costs, adjusted for ASA-classification and surgery type, adds up to EUR 8,584.81 (95% CI EUR 8,332.51 – EUR 8,860.81) in patients without complications. EUR 15,412.96 (95% CI EUR 14,250.22 – EUR 16,708.82) after minor complications, and EUR 29,198.23 (95% CI EUR 27,187.13 – EUR 31,295.78) after major complications (p < 0.001). Conclusion: The results provide an insight into the scope of hospital costs associated with complications. Major complications occur in 20% of patients undergoing MAS and account for 50% of the total
© 2015 S. Karger AG, Basel 0253–4886/15/0322–0150$39.50/0 E-Mail [email protected] www.karger.com/dsu
costs of care. Implementation of a protocol aimed at early diagnosis and treatment of complications might lead to a decrease in morbidity and mortality, but also prove to be cost effective. © 2015 S. Karger AG, Basel
Introduction
Major abdominal surgery (MAS) may be defined as all upper gastrointestinal (UGI), hepatopancreatobilliary (HPB) and colorectal surgery (CRS) with either primary anastomosis and/or stoma. MAS is associated with an overall morbidity rate of 35%. There is a 20% rate of major complications, which require invasive treatment and intensive monitoring [1–3]. Besides intensive treatment, these complications are associated with increased morbidity, mortality, hospital stay and intensive care stay [4, 5]. In 1992, Clavien et al. established a classification system for postoperative complications with a four-level severity grading based on required intervention for complications and length of hospital stay [6]. In 2004, the classification system was reevaluated and refined by Clavien and Dindo et al.; grading is now solely based on the required intervention for complications and has been widely adopted [7, 8]. Many authors have adapted the ClavienDrs. J. Straatman Department of Gastrointestinal Surgery VU Medical Centre, De Boelelaan 1117 Room ZH 7F020, 1081 HV Amsterdam (The Netherlands) E-Mail je.straatman @ vumc.nl
Dindo classification and further divided it into minor and major complications [9]. Minor complications, consisting of grades I and II, require noninvasive treatment with medication or local drainage of an abscess at the bedside. Major complications, consisting of grades III, IV and V, require invasive treatment such as percutaneous drainage, reoperation and/or admission to an Intensive Care Unit (ICU) and might even lead up to death (grade V). Postoperative complications induce stress in patients and affect their quality of life in a significant manner. Moreover, postoperative complications lead to an increased consumption of resources [10]. As part of rising costs in health care, we regard postoperative complications to be a major factor affecting hospital costs. There are insufficient data as to the degree to which complications increase these costs. Hence, the aim of this study is to assess how high the overall costs of postoperative complications are and how this impacts the budget of a surgical department.
Materials and Methods Patient Data Retrospective review of data of patients that underwent Major Abdominal Surgery, defined as all UGI, HPB and CRS resections with either primary anastomosis and/or creation of stoma, in 2009 and 2010 in the Vrije Universiteit Medical Center (VUMC), Amsterdam, the Netherlands. Data on laparoscopic and open procedures, acute and elective procedures and malignant and benign disease were included. Patients younger than 18 years of age were excluded. All patients received perioperatively prophylactic intravenous antibiotics and thromboprophylaxis according to local protocol. Data was recorded with regard to patient data: age, gender, height, weight, medical history, comorbidity and the American Society of Anaesthesiologists (ASA)-classification. Surgical data consisted of indication and type of operation, duration and perioperative blood loss. Postoperative parameters included recording of complications according to Clavien-Dindo classification up to 90 days postoperatively, additional imaging and laboratory tests for diagnosis of complications, intensive care admission, interventional radiology performed, reoperations, hospital admission duration, readmission and mortality.
If a major complication was diagnosed, treatment was initiated immediately and, if necessary, the patient was admitted to the ICU. Interventions usually consisted of percutaneous drainage or relaparotomy. Cost Analysis Cost analysis was considered from a hospital perspective and therefore only hospital costs related to major abdominal surgery were included. Our main objective was to determine the difference in costs between patients following an uncomplicated, minor or major complicated postoperative course. Hence, only those variables for which a difference in costs per course was considered possible and relevant were included. Information on prices of resources was provided by the information and cost management department of the VU University Medical Centre Amsterdam, the Netherlands and by the Dutch health care standards of 2010 [11]. Relevant Costs Costs concerning a complicated postoperative course included the differences in hospital stay, (including length of hospital stay upon re-admission) and ICU stay; costs for diagnostic tests such as laboratory tests and CT scans and costs for reoperation or percutaneous drainage. C-reactive protein (CRP) levels, white blood cell count (WBC) and hemoglobin were assessed. Laboratory parameters were available up to 14 days postoperatively; therefore, costs concerning laboratory tests may be underestimated. Other laboratory parameters are considered beyond the scope of this study. CT-scan imaging is considered the modality of choice in diagnosis of major complications after major abdominal surgery and included in the cost analysis. Other imaging modalities such as plain X-rays and ultrasonography, used less frequently, are not considered in this study. Costs for reoperation were calculated by multiplying operative time by a cost price per minute. Average operative costs consisted of operating room costs and the salaries for personnel (two nurses, one gastrointestinal surgeon, assistant, one anesthesiologist and one anesthesiology nurse) in the operating room. The cost of separate items was provided by the VUMC and it was estimated that the average cost per hour of an operation was EUR 1,020 per hour (EUR 17 per minute). Intervention radiology costs were calculated including the assessment of CT-scan imaging by a radiologist, and placement of drain by a radiologist, including consumables, and was estimated at EUR 424.21. Data regarding off-hour surgery was not available. An overview of costs is depicted in table 2.
Complications All postoperative complications were classified as either minor, labelled by Clavien-Dindo grades I and II or major complications, consisting of grades III, IV and V [7]. Clinical deterioration (such as tachycardia, fever, failure to pass stool, vomiting, insufficient urinary production, pain and abdominal tenderness) and increase in CRP and/or leucocytes resulted in additional examinations, generally consisting of laboratory tests and a CT-scan (Computer Tomography), to diagnose complications. CT scans were performed in a Philips 256 slice Brilliance iCT scanner, with oral, rectal and intravenous contrast.
Statistical Analysis Continuous variables are presented as means and standard deviations. Student’s t-tests were used for comparison. Categorical variables are expressed as frequencies and compared with Chisquare or McNemar analysis as appropriate. A value of p < 0.05 was considered statistically significant. Baseline characteristics of the three patient groups (uncomplicated, minor and major complications) were compared. In order to correct for skewness as measured asymmetry of the probability distribution, and possible bias in cost data and to allow for an estimation of confidence intervals with deemed normality, applied bias-corrected accelerated bootstrapping techniques were used [12, 13]. With bootstrapping 2,000 new datasets are randomly resampled from the original dataset, involving replacement of data (samples can be selected multiple times in one sample) and allow-
Hospital Cost-Analysis of Complications after Major Abdominal Surgery
Dig Surg 2015;32:150–156 DOI: 10.1159/000371861
151
Table 1. Baseline characteristics of patients with an uncomplicated, minor or major complicated postoperative course
Parameter
Uncomplicated
Patients, n (%) Gender, n (%) Male Female Age, years (mean ± SD) ASA score (mean ± SD) Body mass index (BMI), kg/m2 (mean ± SD) Operation type, n (%) Upper GI HPB Lower GI Indication, n (%) Elective Acute Malignant Benign Epidural anesthesia, n (%) Operation Access, n (%) Laparotomy Laparoscopy Conversion Anastomosis, n (%) Ostomy, n (%) Protective ostomy Drain, n (%) Duration of surgery, min ± SD Perioperative blood loss, ml ± SD Hospital stay, days ± SD Intensive care stay Mortality
Minor complication
Major complication
Total
p value
258 (64.7)
59 (14.8)
83 (20.6)
399
148 (57.6) 109 (42.2) 58.7±15.6 1.1±0.6
38 (64.4) 21 (35.6) 66.2±15 1±0.6
49 (59) 34 (20.7) 60.4±14.7 1.3±0.8
235 (58.9) 164 (41.1) 60.2±15.5 1.1±0.7
0.639 0.003 0.005
25.3±5.7
24.9±4.3
24.9±4.7
25.1±5.3
0.832
0.002
35 (47.3) 69 (75.8) 153 (65.4)
13 (17.6) 10 (11) 36 (15.4)
26 (35.1) 12 (13.2) 45 (19.2)
74 (18.5) 92 (22.8) 234 (58.6)
215 (65.5) 42 (59.2) 174 (68) 82 (32) 153 (66.2)
48 (14.6) 11 (15.5) 43 (74.1) 15 (25.9) 29 (12.6)
65 (19.8) 18 (25.4) 55 (66.3) 28 (33.7) 49 (21.2)
328 (82.2) 71 (17.8) 274 (68.7) 125 (31.3) 231 (57.9)
0.63 0.221
155 (60.3) 90 (35) 12 (4.7) 154 (60.2) 47 (43.6) 17 (63) 102 (54.8) 210.3±150 199.4±333 9.7±5.1 2.7±3 0
36 (61) 17 (28.8) 6 (10.2) 43 (16.8) 14 (17.5) 6 (22.2) 28 (15.1) 226.3±91 291.9±452 17.8±15.2 10.2±19.2 0
57 (68.7) 22 (26.5) 4 (18.2) 59 (23) 19 (23.8) 4 (14.8) 56 (30.1) 234.1±95 611.2±951 35±36.7 17±22.3 14 (3.5)
248 (62.2) 129 (28.6) 22 (4.8) 256 (64.2) 80 (20.1) 27 (6.8) 186 (46.6) 217.6±132.7 295.7±554 16.1±20.7 11.3±18.8 14 (3.5)
0.368 0.058 0.341 0.12
