- Email: [email protected]
JACS CME-1 Featured Article, Volume 204, June 2007
CONTINUING MEDICAL EDUCATION PROGRAM
JACS CME-1 FEATURED ARTICLE, VOLUME 204, JUNE 2007 Comparison of risk-adjusted 30-day post-operative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men Henderson WG, Khuri SF, Mosca C, et al J Am Coll Surg 2007;204:1103–1114 Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study Virani S, Michaelson JS, Hutter MM, et al J Am Coll Surg 2007;204:1284–1292 Objectives: After reading the featured articles published in this issue of the Journal of the American College of Surgeons (JACS) participants in the JACS CME program should be able to demonstrate increased understanding of the material specific to the article featured and be able to apply relevant information to clinical practice. Objectives are stated at the beginning of each featured article; the questions follow with five response choices, and a critique discussing the objective. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. The JACS CME program fulfills the ACCME essentials. The American College of Surgeons designates this educational activity for a maximum of 2 Category 1 credits toward the AMA Physician’s Recognition Award. Each physician should claim only those credits that he/ she actually spent in the educational activity.
You can earn 4 CME credits using JACS CME Online, at http://jacscme.facs.org, or you can earn 2 CME credit if you submit this page by fax (see instructions in box below). JACS CME Online provides four articles from each issue for 4 credits per month. The articles this month on JACS CME Online are: Comparison of risk-adjusted 30-day post-operative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men. Henderson WG, Khuri SF, Mosca C, et al. Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study. Virani S, Michaelson JS, Hutter MM, et al. Multivariable predictors of postoperative venous thromboembolic events after general and vascular surgery: results from the Patient Safety in Surgery Study. Rogers Jr SO, Kilaru RK, Hosokawa P, et al.
Questions: Wendy Cowles Husser, MA, MPA Executive Editor, JACS 633 N Saint Clair Street, Chicago, IL 60611 312-202-5306 (ph) 312-202-5027 (fax) [email protected]
© 2007 by the American College of Surgeons Published by Elsevier Inc.
1305
ISSN 1072-7515/07/$32.00 doi:10.1016/j.jamcollsurg.2007.03.026
1306
Continuing Medical Education Program
A comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in women. Fink AS, Hutter MM, Campbell Jr DC, et al. Comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men
Henderson WG, Khuri SF, Mosca C, et al. J Am Coll Surg 2007;204:1103–1114 Learning Objectives: After study of this article the surgeon will be able to describe the risk-adjusted comparisons of surgical outcomes in general surgery in men between the VA healthcare system and selected university medical centers, and the potential limitations of this study. Question 1
Which of the following statements concerning riskadjusted comparisons of surgical outcomes for general surgery in men between the VA healthcare system and selected university medical centers is correct? a) Risk-adjusted 30-day postoperative mortality and morbidity are equivalent in the VA healthcare system and the selected university medical centers. b) Risk-adjusted 30-day postoperative mortality is higher in the VA healthcare system compared to the selected university medical centers, but risk-adjusted 30-day postoperative morbidity is equivalent in the two sectors. c) Risk-adjusted 30-day postoperative morbidity is higher in the VA healthcare system, but risk-adjusted 30-day postoperative mortality is equivalent in the two sectors. d) Risk-adjusted 30-day postoperative mortality and morbidity is better in the VA healthcare system compared to the selected university medical centers. e) Risk-adjusted surgical outcomes between the two sectors cannot be compared because the two healthcare sectors are so different. Critique: The unadjusted 30-day postoperative mortality rate was higher in the VA compared to the private sector (2.62% vs. 2.03%, p⫽0.0002), while the unadjusted morbidity rate was lower in the VA compared to the private sector (12.24% vs. 13.99%, p⬍0.0001). The VA patients were older and had higher ASA class than the private sector patients, but the two populations were fairly equivalent in terms of preoperative comorbidities
J Am Coll Surg
and abnormal preoperative laboratory variables. After risk adjustment, the odds ratio for mortality for VA vs. private sector patients was 1.23 (95% confidence interval 1.08 to 1.41), meaning that the VA patients had a 23% increased risk for mortality. The two systems were equivalent for risk-adjusted postoperative morbidity because the indicator variable for healthcare system in the logistic regression analysis was not statistically significant at the p⫽0.05 level. Application of the NSQIP methodology in the same fashion in the two healthcare sectors allowed for proper comparisons between riskadjusted postoperative mortality and morbidity outcomes, even though patient characteristics are quite different between the two sectors. Question 2
Potential limitations of this study include: a) small sample size. b) the NSQIP data were collected in different ways and included different predictor variables in the two healthcare sectors. c) potential differences in ascertainment of 30-day postoperative deaths. d) the statistical models for predicting mortality and morbidity were not robust enough for adjustment purposes. e) differences in types of operations of the two healthcare sectors were not accounted for. Critique: The VA system has a centralized vital status database that is merged every 6 months with the VANSQIP data, so that the ascertainment of 30-day postoperative deaths is excellent. This merging is done in addition to the site nurses reports of 30-day deaths to ensure that all deaths are captured. This is not possible in the private sector currently because of data confidentiality issues. The sample sizes of this study of 94,098 male general surgery patients in the VA and 18,399 general surgery patients in the private sector are very large sample sizes which are rarely obtained in other studies. NSQIP variables and data collection are done identically in both healthcare systems. The statistical model for predicting mortality is very robust, with a c-index of 0.921. The statistical model for predicting morbidity is also robust, with a c-index of 0.807, although somewhat less than for the mortality model. Differences in types of operations in the two healthcare sectors are somewhat accounted for in the statistical models using the
Vol. 204, No. 6, June 2007
workRVU variable as a measure of the complexity of each operation. Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study
Virani S, Michaelson JS, Hutter MM, et al J Am Coll Surg 2007;204:1284–1292 Learning Objectives: After study of this article, the reader will be able to describe common complications of liver surgery and co-morbidities associated with complications and mortality. Question 1
Which of the following statements concerning patients undergoing liver resection is correct? a) The operative mortality rate in recent years is approximately 10%. b) Low preoperative serum albumin levels are associated with a greater risk for post-operative complications. c) The number of resections is declining in recent years because of greater use of ablative techniques. d) Post-operative complications occur in approximately 5% of patients. e) A majority of published reports on outcomes following liver resection involved multicenter prospective studies. Critique: Liver resection is now performed more frequently than in prior decades, and the number of liver resections performed annually doubled from 1988 to 2000. Published literature suggests a reduction in morbidity and mortality rates in recent years, with many high volume centers reporting mortality rates less than 5%. High volume hospitals (⬎ 10 resections per year) have lower mortality rates than low volume hospitals. Advances in peri-operative management and surgical techniques have improved mortality rates; however, reported morbidity rates remain high and range from 23% to 56% depending on the indication for surgery. Nearly
Continuing Medical Education Program 1307
all of the reports rely on retrospectively collected data from a single center. The current report represents an analysis of one of very few prospectively collected datasets from multiple hospitals. Stepwise logistic regression analysis identified several preoperative factors associated with morbidity, including low serum albumin, SGOT ⬎ 40, previous cardiac surgery, work RVU, history of severe COPD, and open wound or wound infection. Question 2
Which of the following statements concerning patients undergoing liver resection is correct? a) Patients with liver metastases have more complications than those with primary liver tumors. b) Post-operative ileus is one of the most common complications. c) ASA 3 or higher is associated with a greater risk for mortality. d) Post-operative complications only minimally prolong hospitalization duration . e) Definitions of morbidity are well defined and consistent throughout the published literature. Critique: Patients that undergo liver resection for metastases (e.g. colon or rectal carcinoma liver metastases) generally do not have cirrhosis, whereas approximately 80% of patients with primary liver tumors have underlying cirrhosis or other chronic liver disease. The presence of cirrhosis is associated with a greater risk of morbidity and mortality. The most common complications after liver resection are infections, respiratory complications, and bleeding. Post-operative ileus and small bowel obstructions are rare. Comorbidities associated with mortality are male gender, ASA 3 or higher, presence of ascites, dyspnea, and COPD. Patients experiencing complications stay in the hospital over twice as long on average compared to those without complications (15 days compared to 7 days). Definitions for morbidity are not standardized and varying criteria for morbidity make the results of various studies difficult to compare.
JACS CME-1 FEATURED ARTICLE, VOLUME 204, JUNE 2007 Comparison of risk-adjusted 30-day post-operative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men Henderson WG, Khuri SF, Mosca C, et al J Am Coll Surg 2007;204:1103–1114 Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study Virani S, Michaelson JS, Hutter MM, et al J Am Coll Surg 2007;204:1284–1292 Objectives: After reading the featured articles published in this issue of the Journal of the American College of Surgeons (JACS) participants in the JACS CME program should be able to demonstrate increased understanding of the material specific to the article featured and be able to apply relevant information to clinical practice. Objectives are stated at the beginning of each featured article; the questions follow with five response choices, and a critique discussing the objective. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. The JACS CME program fulfills the ACCME essentials. The American College of Surgeons designates this educational activity for a maximum of 2 Category 1 credits toward the AMA Physician’s Recognition Award. Each physician should claim only those credits that he/ she actually spent in the educational activity.
You can earn 4 CME credits using JACS CME Online, at http://jacscme.facs.org, or you can earn 2 CME credit if you submit this page by fax (see instructions in box below). JACS CME Online provides four articles from each issue for 4 credits per month. The articles this month on JACS CME Online are: Comparison of risk-adjusted 30-day post-operative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men. Henderson WG, Khuri SF, Mosca C, et al. Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study. Virani S, Michaelson JS, Hutter MM, et al. Multivariable predictors of postoperative venous thromboembolic events after general and vascular surgery: results from the Patient Safety in Surgery Study. Rogers Jr SO, Kilaru RK, Hosokawa P, et al.
Questions: Wendy Cowles Husser, MA, MPA Executive Editor, JACS 633 N Saint Clair Street, Chicago, IL 60611 312-202-5306 (ph) 312-202-5027 (fax) [email protected]
© 2007 by the American College of Surgeons Published by Elsevier Inc.
1305
ISSN 1072-7515/07/$32.00 doi:10.1016/j.jamcollsurg.2007.03.026
1306
Continuing Medical Education Program
A comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in women. Fink AS, Hutter MM, Campbell Jr DC, et al. Comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men
Henderson WG, Khuri SF, Mosca C, et al. J Am Coll Surg 2007;204:1103–1114 Learning Objectives: After study of this article the surgeon will be able to describe the risk-adjusted comparisons of surgical outcomes in general surgery in men between the VA healthcare system and selected university medical centers, and the potential limitations of this study. Question 1
Which of the following statements concerning riskadjusted comparisons of surgical outcomes for general surgery in men between the VA healthcare system and selected university medical centers is correct? a) Risk-adjusted 30-day postoperative mortality and morbidity are equivalent in the VA healthcare system and the selected university medical centers. b) Risk-adjusted 30-day postoperative mortality is higher in the VA healthcare system compared to the selected university medical centers, but risk-adjusted 30-day postoperative morbidity is equivalent in the two sectors. c) Risk-adjusted 30-day postoperative morbidity is higher in the VA healthcare system, but risk-adjusted 30-day postoperative mortality is equivalent in the two sectors. d) Risk-adjusted 30-day postoperative mortality and morbidity is better in the VA healthcare system compared to the selected university medical centers. e) Risk-adjusted surgical outcomes between the two sectors cannot be compared because the two healthcare sectors are so different. Critique: The unadjusted 30-day postoperative mortality rate was higher in the VA compared to the private sector (2.62% vs. 2.03%, p⫽0.0002), while the unadjusted morbidity rate was lower in the VA compared to the private sector (12.24% vs. 13.99%, p⬍0.0001). The VA patients were older and had higher ASA class than the private sector patients, but the two populations were fairly equivalent in terms of preoperative comorbidities
J Am Coll Surg
and abnormal preoperative laboratory variables. After risk adjustment, the odds ratio for mortality for VA vs. private sector patients was 1.23 (95% confidence interval 1.08 to 1.41), meaning that the VA patients had a 23% increased risk for mortality. The two systems were equivalent for risk-adjusted postoperative morbidity because the indicator variable for healthcare system in the logistic regression analysis was not statistically significant at the p⫽0.05 level. Application of the NSQIP methodology in the same fashion in the two healthcare sectors allowed for proper comparisons between riskadjusted postoperative mortality and morbidity outcomes, even though patient characteristics are quite different between the two sectors. Question 2
Potential limitations of this study include: a) small sample size. b) the NSQIP data were collected in different ways and included different predictor variables in the two healthcare sectors. c) potential differences in ascertainment of 30-day postoperative deaths. d) the statistical models for predicting mortality and morbidity were not robust enough for adjustment purposes. e) differences in types of operations of the two healthcare sectors were not accounted for. Critique: The VA system has a centralized vital status database that is merged every 6 months with the VANSQIP data, so that the ascertainment of 30-day postoperative deaths is excellent. This merging is done in addition to the site nurses reports of 30-day deaths to ensure that all deaths are captured. This is not possible in the private sector currently because of data confidentiality issues. The sample sizes of this study of 94,098 male general surgery patients in the VA and 18,399 general surgery patients in the private sector are very large sample sizes which are rarely obtained in other studies. NSQIP variables and data collection are done identically in both healthcare systems. The statistical model for predicting mortality is very robust, with a c-index of 0.921. The statistical model for predicting morbidity is also robust, with a c-index of 0.807, although somewhat less than for the mortality model. Differences in types of operations in the two healthcare sectors are somewhat accounted for in the statistical models using the
Vol. 204, No. 6, June 2007
workRVU variable as a measure of the complexity of each operation. Morbidity and mortality after liver resection: results of the Patient Safety in Surgery Study
Virani S, Michaelson JS, Hutter MM, et al J Am Coll Surg 2007;204:1284–1292 Learning Objectives: After study of this article, the reader will be able to describe common complications of liver surgery and co-morbidities associated with complications and mortality. Question 1
Which of the following statements concerning patients undergoing liver resection is correct? a) The operative mortality rate in recent years is approximately 10%. b) Low preoperative serum albumin levels are associated with a greater risk for post-operative complications. c) The number of resections is declining in recent years because of greater use of ablative techniques. d) Post-operative complications occur in approximately 5% of patients. e) A majority of published reports on outcomes following liver resection involved multicenter prospective studies. Critique: Liver resection is now performed more frequently than in prior decades, and the number of liver resections performed annually doubled from 1988 to 2000. Published literature suggests a reduction in morbidity and mortality rates in recent years, with many high volume centers reporting mortality rates less than 5%. High volume hospitals (⬎ 10 resections per year) have lower mortality rates than low volume hospitals. Advances in peri-operative management and surgical techniques have improved mortality rates; however, reported morbidity rates remain high and range from 23% to 56% depending on the indication for surgery. Nearly
Continuing Medical Education Program 1307
all of the reports rely on retrospectively collected data from a single center. The current report represents an analysis of one of very few prospectively collected datasets from multiple hospitals. Stepwise logistic regression analysis identified several preoperative factors associated with morbidity, including low serum albumin, SGOT ⬎ 40, previous cardiac surgery, work RVU, history of severe COPD, and open wound or wound infection. Question 2
Which of the following statements concerning patients undergoing liver resection is correct? a) Patients with liver metastases have more complications than those with primary liver tumors. b) Post-operative ileus is one of the most common complications. c) ASA 3 or higher is associated with a greater risk for mortality. d) Post-operative complications only minimally prolong hospitalization duration . e) Definitions of morbidity are well defined and consistent throughout the published literature. Critique: Patients that undergo liver resection for metastases (e.g. colon or rectal carcinoma liver metastases) generally do not have cirrhosis, whereas approximately 80% of patients with primary liver tumors have underlying cirrhosis or other chronic liver disease. The presence of cirrhosis is associated with a greater risk of morbidity and mortality. The most common complications after liver resection are infections, respiratory complications, and bleeding. Post-operative ileus and small bowel obstructions are rare. Comorbidities associated with mortality are male gender, ASA 3 or higher, presence of ascites, dyspnea, and COPD. Patients experiencing complications stay in the hospital over twice as long on average compared to those without complications (15 days compared to 7 days). Definitions for morbidity are not standardized and varying criteria for morbidity make the results of various studies difficult to compare.