The Department of Veterans Affairs' NSQIP: the first national, validated, outcome-based, risk-adjusted, and peer-controlled program for the measurement and enhancement of the quality of surgical care. National VA Surgical Quality Improvement Program

Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey

OBJECTIVE

Although quality assessment is gaining increasing attention, there is still no consensus on how to define and grade postoperative complications. This shortcoming hampers comparison of outcome data among different centers and therapies and over time.

PATIENTS AND METHODS

A classification of complications published by one of the authors in 1992 was critically re-evaluated and modified to increase its accuracy and its acceptability in the surgical community. Modifications mainly focused on the manner of reporting life-threatening and permanently disabling complications. The new grading system still mostly relies on the therapy used to treat the complication. The classification was tested in a cohort of 6336 patients who underwent elective general surgery at our institution. The reproducibility and personal judgment of the classification were evaluated through an international survey with 2 questionnaires sent to 10 surgical centers worldwide.

RESULTS

The new ranking system significantly correlated with complexity of surgery (P < 0.0001) as well as with the length of the hospital stay (P < 0.0001). A total of 144 surgeons from 10 different centers around the world and at different levels of training returned the survey. Ninety percent of the case presentations were correctly graded. The classification was considered to be simple (92% of the respondents), reproducible (91%), logical (92%), useful (90%), and comprehensive (89%). The answers of both questionnaires were not dependent on the origin of the reply and the level of training of the surgeons.

CONCLUSIONS

The new complication classification appears reliable and may represent a compelling tool for quality assessment in surgery in all parts of the world.

Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey

OBJECTIVE

Although quality assessment is gaining increasing attention, there is still no consensus on how to define and grade postoperative complications. This shortcoming hampers comparison of outcome data among different centers and therapies and over time.

PATIENTS AND METHODS

A classification of complications published by one of the authors in 1992 was critically re-evaluated and modified to increase its accuracy and its acceptability in the surgical community. Modifications mainly focused on the manner of reporting life-threatening and permanently disabling complications. The new grading system still mostly relies on the therapy used to treat the complication. The classification was tested in a cohort of 6336 patients who underwent elective general surgery at our institution. The reproducibility and personal judgment of the classification were evaluated through an international survey with 2 questionnaires sent to 10 surgical centers worldwide.

RESULTS

The new ranking system significantly correlated with complexity of surgery (P < 0.0001) as well as with the length of the hospital stay (P < 0.0001). A total of 144 surgeons from 10 different centers around the world and at different levels of training returned the survey. Ninety percent of the case presentations were correctly graded. The classification was considered to be simple (92% of the respondents), reproducible (91%), logical (92%), useful (90%), and comprehensive (89%). The answers of both questionnaires were not dependent on the origin of the reply and the level of training of the surgeons.

CONCLUSIONS

The new complication classification appears reliable and may represent a compelling tool for quality assessment in surgery in all parts of the world.

Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey

OBJECTIVE

Although quality assessment is gaining increasing attention, there is still no consensus on how to define and grade postoperative complications. This shortcoming hampers comparison of outcome data among different centers and therapies and over time.

PATIENTS AND METHODS

A classification of complications published by one of the authors in 1992 was critically re-evaluated and modified to increase its accuracy and its acceptability in the surgical community. Modifications mainly focused on the manner of reporting life-threatening and permanently disabling complications. The new grading system still mostly relies on the therapy used to treat the complication. The classification was tested in a cohort of 6336 patients who underwent elective general surgery at our institution. The reproducibility and personal judgment of the classification were evaluated through an international survey with 2 questionnaires sent to 10 surgical centers worldwide.

RESULTS

The new ranking system significantly correlated with complexity of surgery (P < 0.0001) as well as with the length of the hospital stay (P < 0.0001). A total of 144 surgeons from 10 different centers around the world and at different levels of training returned the survey. Ninety percent of the case presentations were correctly graded. The classification was considered to be simple (92% of the respondents), reproducible (91%), logical (92%), useful (90%), and comprehensive (89%). The answers of both questionnaires were not dependent on the origin of the reply and the level of training of the surgeons.

CONCLUSIONS

The new complication classification appears reliable and may represent a compelling tool for quality assessment in surgery in all parts of the world.

The effect of center volume on pancreas transplant outcomes

BACKGROUND

Caseload often correlates with improved outcomes for several surgical procedures, including solid organ transplantation. Given the unique nature of pancreas transplantation and large variation in transplant center volumes, this study aims to determine whether center volume affects patient and graft survival after pancreas transplantation.

METHODS

Registry data on all forms of whole organ pancreas transplants performed between 1995 and 2000 were obtained from the United Network for Organ Sharing. Patient and graft survival rates were followed until 2002. Center volume then was categorized as: low (< 10/year), medium (10-20/year), high (21-50/year), and very high (< 50/year). Cox proportional hazard regression models were developed to evaluate factors affecting pancreas transplant outcomes.

RESULTS

Very-high-volume centers were more likely to do pancreas after kidney transplant, pancreas transplant alone, pancreas with kidney transplant, and repeat transplants, while other centers more frequently performed simultaneous pancreas-kidney transplants (P < .001). Very-high-volume centers were more likely to transplant older recipients and less likely to transplant minority or Medicaid patients. Low-volume centers tended to accept pancreatic allografts from younger donors and had the longest waiting times. In models adjusting for differences in patient population, there were no differences in patient survival. However, low-volume centers had a slightly increased risk of graft loss compared to other centers. Early graft loss was similar among all centers, but medium-volume centers were at increased risk for late graft loss.

CONCLUSIONS

Low center volume is not associated with increased mortality after pancreas transplantation. Other factors appear to be more important than center volume in determining pancreas transplant outcomes.

The Association of Coloproctology of Great Britain and Ireland study of large bowel obstruction caused by colorectal cancer

BACKGROUND

This study was designed to investigate the early outcomes after surgical treatment of malignant large bowel obstruction (MBO) and to identify risk factors affecting operative mortality.

METHODS

Data were prospectively collected from 1046 patients with MBO by 294 surgeons in 148 UK hospitals during a 12-month period from April 1998. A predictive model of in-hospital mortality was developed using a 3-level Bayesian logistic regression analysis.

RESULTS

The median age of patients was 73 years (interquartile range 64-80). Of the 989 patients having surgery, 91.7% underwent bowel resection with an overall mortality of 15.7%. The multilevel model used the following independent risk factors to predict mortality: age (odds ratio [OR] 1.85 per 10 year increase), American Society of Anesthesiologists grade (OR for American Society of Anesthesiologists grade I versus II,III,IV-V = 3.3,11.7,22.2), Dukes' staging (OR for Dukes' A versus B,C,D = 2.0, 2.1, 6.0), and mode of surgery (OR for scheduled versus urgent, emergency = 1.6, 2.3). A significant interhospital variability in operative mortality was evident with increasing age (variance = 0.004, SE = 0.001, P < 0.001). No detectable caseload effect was demonstrated between specialist colorectal and other general surgeons.

CONCLUSIONS

Using prognostic models, it was possible to develop a risk-stratification index that accurately predicted survival in patients presenting with malignant large bowel obstruction. The methodology and model for risk adjusted survival can set the reference point for more accurate and reliable comparative analysis and be used as an adjunct to the process of informed consent.

Practicing surgeons lead in quality care, safety, and cost control

OBJECTIVE

To report the experiences of 66 surgical specialists from 15 different hospitals who performed 43 CPT-based procedures more than 16,000 times.

SUMMARY BACKGROUND DATA

Surgeons are under increasing pressure to demonstrate patient safety data as quantitated by objective and subjective outcomes that meet or exceed the standards of benchmark institutions or databases.

METHODS

Data from 66 surgical specialists on 43 CPT-based procedures were accessioned over a 4-year period. The hospitals vary from a small 30-bed hospital to large teaching hospitals. All reported deaths and complications were verified from hospital and office records and compared with benchmarks.

RESULTS

Over a 4-year inclusive period (1999-2002), 16,028 elective operations were accessioned. There was a total 1.4% complication rate and 0.05% death rate. A system has been developed for tracking outcomes. A wide range of improvements have been identified. These include the following: 1) improved classification of indications for systemic prophylactic antibiotic use and reduction in the variety of drugs used, 2) shortened length of stay for standard procedures in different surgical specialties, 3) adherence to strict indicators for selected operative procedures, 4) less use of costly diagnostic procedures, 5) decreased use of expensive home health services, 6) decreased use of very expensive drugs, 7) identification of the unnecessary expense of disposable laparoscopic devices, 8) development of a method to compare a one-surgeon hospital with his peers, and 9) development of unique protocols for interaction of anesthesia and surgery. The system also provides a very good basis for confirmation of patient safety and improvement therein.

CONCLUSIONS

Since 1998, Quality Surgical Solutions, PLLC, has developed simple physician-authored protocols for delivering high-quality and cost-effective surgery that measure up to benchmark institutions. We have discovered wide areas for improvements in surgery by adherence to simple protocols, minimizing death and complications and clarifying cost issues.

Breast cancer surgery trends and outcomes: results from a national department of veterans affairs study

BACKGROUND

This study examined trends and outcomes for breast cancer surgery performed at Department of Veterans Affairs (VA) hospitals.

STUDY DESIGN

We examined breast cancer operations performed in VA hospitals from October 1991 to September 1997. Data from the VA National Surgical Quality Improvement Program, surgical pathology reports, discharge data, and outpatient data were used. Surgical outcomes included postoperative length of stay, 30-day morbidity rates, 1-year surgery-related readmission rates, and mortality. An expert panel of breast cancer clinicians identified surgery-related hospital readmissions. Hierarchical regression analysis was used to identify patient, provider, and hospital characteristics associated with postoperative length of stay, and 30-day morbidity.

RESULTS

From October 1991 to September 1997 1,333 breast operations were performed, ranging from 1 to 38 on average per hospital; 478 operations were for breast cancer. Among breast cancer surgery patients, 25% were men. Thirty-day morbidity rates, 1-year hospital readmission rates, and mortality were very low for both men and women. Postoperative length of stay averaged 6.8 days. Lower income, longer operation times, and older age increased the likelihood of 30-day morbidity. Lower functional status, older age, longer operation time, and lower average annual volume of procedures increased postoperative length of stay. Documentation of the extent of disease and surgical margin in pathology reports was poor in medical records.

CONCLUSIONS

Hospital stays were longer, and morbidity and readmission rates for patients having breast cancer operations at VA hospitals were comparable to those reported for private sector hospitals.

Impact of surgical volume on mortality and length of stay after nephrectomy

OBJECTIVES

To evaluate the volume-outcome relationship in patients undergoing nephrectomy for neoplastic disease by examining the impact of the number of cases performed on in-hospital mortality and length of stay. Surgical volume is associated with postoperative mortality for many complex procedures; however, this relationship has not been characterized for patients undergoing nephrectomy for neoplastic disease.

METHODS

Using the Nationwide Inpatient Sample database, 20,765 patients who underwent nephrectomy for neoplasm from 1993 through 1997 were identified by International Classification of Disease, Ninth Revision codes. Cases were stratified into volume groups on the basis of annual nephrectomy rates: low-volume hospitals performed 1 to 14 nephrectomies per year, medium-volume hospitals performed 15 to 33 per year, and high-volume hospitals performed more than 33 per year. Unadjusted and risk-adjusted analyses were performed.

RESULTS

Overall mortality was 1.39%. Mortality declined as surgical volume increased. The mortality rate for low-volume hospitals was 1.60% versus 1.49% for medium-volume hospitals and 1.04% for high-volume hospitals (P = 0.017). After adjusting for case mix, high-volume hospitals had a 32% lower risk of in-hospital mortality than medium-volume hospitals (P = 0.029) and a 25% lower risk than low-volume hospitals (P = 0.094). Length of stay was not affected by hospital volume. Other independent risk factors for in-hospital mortality included age older than 65 years, chronic pulmonary disease, metastatic disease, and the urgent nature of the admission.

CONCLUSIONS

A greater surgical volume, age younger than 65 years, elective conditions, and less comorbidity are associated with a significantly decreased risk of in-hospital mortality after nephrectomy. These findings provide compelling evidence that hospital volume and patient characteristics have important effects on surgical outcome specific to renal neoplasms.

Risk Adjusting Rehabilitation Outcomes

The complexity and mix of rehabilitation patients varies across clinicians and institutions. Comparisons of outcomes across providers must therefore adjust for differences in risk factors across patient populations. Research on risk adjustment has generally focused on acute care hospital outcomes, although techniques for risk adjusting financial outcomes are fairly well developed in rehabilitation, primarily to support Medicare and other prospective payment systems. This article reviews important methodologic issues in risk adjusting rehabilitation outcomes in observational studies of routine clinical practice or for management, such as assessing quality or costs of care. Risk adjusting rehabilitation outcomes is more difficult than risk adjusting other clinical results, such as outcomes of many acute care services. At the outset, characterizing rehabilitation interventions is frequently difficult. Furthermore, outcomes are diverse and depend on myriad factors, including patients' physical and cognitive abilities, underlying medical diseases, sensory and emotional factors, willingness to participate in care, and supportive environments. No risk-adjustment approach can control for every factor affecting outcomes of care. Knowing which risk factors are missing helps guide interpretation of the results and determines how well risk-adjusted outcomes fairly compare providers or treatments.

Influence of renal insufficiency on limb loss and mortality after initial lower extremity surgical revascularization

OBJECTIVE

Limb loss after lower extremity surgical revascularization occurs relatively frequently in patients receiving dialysis. The goal of the present study was to determine whether patients with milder degrees of renal insufficiency are also at risk for this complication.

MATERIAL AND METHODS

This cohort study was carried out at the Department of Veterans Affairs (VA). The study sample consisted of 9932 patients undergoing an initial surgical revascularization procedure between October 1, 1995, and September 30, 2000, recorded by the VA National Surgical Quality Improvement Program (NSQIP). We examined the occurrence of major amputation within 1 year of lower extremity surgical revascularization by level of renal function.

RESULTS

Eleven percent of study patients underwent major lower extremity amputation within 1 year of NSQIP-documented lower extremity revascularization surgery: 10% (739 of 7335) of patients with normal renal function, 11% (251 of 2210) of patients with moderately reduced renal function, 12% (24 of 205) of patients with severe renal insufficiency, and 29% (53 of 182) of patients receiving dialysis. After adjustment for demographic characteristics and comorbid conditions, only patients receiving dialysis were at significantly increased risk for amputation, compared with patients with normal renal function (odds ratio, 2.46; 95% confidence interval, 1.74-3.47; P<.001). Compared with all other veterans undergoing bypass procedures, patients receiving dialysis were more likely to have a wound infection; a diagnostic code for lower extremity gangrene, infection, or ischemic ulceration; an elevated white blood cell count; and preoperative sepsis at the time of initial revascularization. In addition, they were more likely to have a preoperative hospital stay longer than 1 week, undergo concurrent minor amputation, and undergo an outflow (vs inflow) procedure.

CONCLUSION

Only patients receiving dialysis, and not patients with milder degrees of renal insufficiency, appear to be at higher risk for limb loss after revascularization, compared with patients with normal renal function. Further studies are needed to determine why patients receiving dialysis are at a singularly increased risk for limb loss after lower extremity revascularization and whether their more frequent presentation with limb-threatening infection at the time of revascularization reflects late presentation for surgery or a more rapid course of peripheral arterial disease in this patient group.

Surgery for Hepatocellular Carcinoma: Does It Improve Survival?

BACKGROUND

The incidence and mortality of hepatocellular carcinoma (HCC) are increasing in the United States. Whether surgery is associated with improved survival at the population level is relatively unknown. To address this question, we used a population-based cancer registry to compare survival outcomes between patients receiving and not receiving surgery with similar tumor sizes and health status.

METHODS

By using the Surveillance, Epidemiology, and End Results database, we identified HCC patients who had surgically resectable disease as defined by published expert guidelines. After excluding patients with contraindications to surgery, we performed both survival analysis and Cox regression to identify predictors of improved survival.

RESULTS

Of the 4008 patients diagnosed with HCC between 1988 and 1998, 417 were candidates for surgical resection. The mean age was 63.6 years; mean tumor size was 3.3 cm. The 5-year overall survival with surgery was 33% with a mean of 47.1 months; without surgery, the 5-year overall survival was 7% with a mean of 17.9 months (P <.001). In the multivariate Cox regression, surgery was significantly associated with improved survival (P <.001). Specifically, patients who received surgery had a 55% decreased rate of death compared with patients who did not have surgery, even after controlling for tumor size, age, sex, and race.

CONCLUSIONS

This study shows that surgical therapy is associated with improved survival in patients with unifocal, nonmetastatic HCC tumors <5 cm. If this is confirmed in future studies, efforts should be made to ensure that appropriate patients with resectable HCC receive high-quality care, as well as the opportunity for potentially curative surgery.

Incidence of Serious Complications After Uvulopalatopharyngoplasty

OBJECTIVES

Uvulopalatopharyngoplasty (UPPP) is the most common surgical treatment for obstructive sleep apnea (OSA). Anatomic and physiologic abnormalities associated with OSA can make perioperative management difficult. Only single-site case series provide current estimates of the incidence of perioperative complications, with a pooled crude serious complication rate of 3.5% and a crude mortality rate of 0.4%. The primary objective of this study was to calculate the incidence of perioperative morbidity and mortality in a large, multisite cohort of UPPP patients.

STUDY DESIGN

Prospective cohort study of adults undergoing inpatient UPPP with or without other concurrent procedures

METHODS

The serious complication and 30-day mortality rates were calculated from the Department of Veterans Affairs (VA) National Surgical Quality Improvement Program database of prospectively collected outcomes of all VA inpatient surgeries nationally 1991 to 2001. Serious complications were defined by 15 specific life-threatening complications. Deaths were captured whether the patient was in the hospital or discharged.

RESULTS

Veteran patients (n = 3130) had a mean age of 50 years and were predominantly male (97%). The serious nonfatal complication rate was 1.5% (47/3,130) (95% confidence interval [CI] 1.1%, 1.9%). The 30-day mortality rate was 0.2% (7/3130) (95% CI 0.1%, 0.4%). There was no significant effect of year of surgery or patient age on the risk of serious complication or death.

CONCLUSION

The incidence of serious nonfatal complications and 30-day mortality after UPPP are 1.5% and 0.2%, respectively, in a large cohort of UPPP patients at veteran hospitals.

The roles of government in improving health care quality and safety

BACKGROUND

Discussions surrounding the role of government have been and continue to be a favorite American pastime. A framework is provided for understanding the 10 roles that government plays in improving health care quality and safety in the United States. Examples of proposed federal actions to reduce medical errors and enhance patient safety are provided to illustrate the 10 roles: (1) purchase health care, (2) provide health care, (3) ensure access to quality care for vulnerable populations, (4) regulate health care markets, (5) support acquisition of new knowledge, (6) develop and evaluate health technologies and practices, (7) monitor health care quality, (8) inform health care decision makers, (9) develop the health care workforce, and (10) convene stakeholders from across the health care system.

CONCLUSION

Government's responsibility to protect and advance the interests of society includes the delivery of high-quality health care. Because the market alone cannot ensure all Americans access to quality health care, the government must preserve the interests of its citizens by supplementing the market where there are gaps and regulating the market where there is inefficiency or unfairness. The ultimate goal of achieving high quality of care will require strong partnerships among federal, state, and local governments and the private sector. Translating general principles regarding the appropriate role of government into specific actions within a rapidly changing, decentralized delivery system will require the combined efforts of the public and private sectors.

Validation of POSSUM scoring systems for audit of major hepatectomy

Background

The aim of the study was to validate the use of Physiological and Operative Severity Score in the enUmeration of Mortality and morbidity (POSSUM) and Portsmouth (P) POSSUM scoring systems to predict postoperative mortality in a group of Chinese patients who had a major hepatectomy for hepatocellular carcinoma.

Methods

A retrospective analysis was performed on data collected prospectively over a 6-year interval from January 1997 to December 2002. The mortality risks were calculated using both the POSSUM and the P-POSSUM equations.

Results

Two hundred and fifty-nine patients underwent major hepatectomy; there were 17 (6·6 per cent) postoperative deaths. Of 32 preoperative and intraoperative variables studied, age, smoking habit, serum creatinine concentration, American Society of Anesthesiologists grade, and physiological and operative severity scores were found to be significant factors predicting mortality. On multivariate analysis only the physiological and operative severity scores were independent variables. The POSSUM system overpredicted mortality risk (14·2 per cent) and there was a significant lack of fit in these patients (χ2 = 14·1, 3 d.f., P = 0·003). The mortality rate predicted by P-POSSUM was 4·2 per cent and showed no significant lack of fit (χ2 = 7·6, 3 d.f., P = 0·055), indicating that it predicted outcome effectively. A new logistic equation was derived from the present patient data set that requires testing prospectively.

Conclusion

P-POSSUM significantly predicted outcome in Chinese patients who had major hepatectomy for hepatocellular carcinoma. A modified disease-specific equation requires further testing.

Perioperative beta-blockade: a survey of physician attitudes in the department of veterans Affairs

OBJECTIVE

To delineate clinician opinion on the efficacy, safety, and logistics of perioperative beta-adrenergic blockade for patients undergoing noncardiac surgery.

DESIGN

Survey of opinions and clinical practices.

SETTING

Internet-based survey form.

PARTICIPANTS

Members of the Associations of Veterans Affairs Anesthesiologists and Surgeons and chiefs of cardiology in centers with surgical programs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred twenty-seven responses from 62 Veterans Affairs Medical Centers in 35 states (57 anesthesiologists, 45 surgeons, 25 cardiologists) were analyzed. Ninety-two percent agreed that it is effective in reducing short-term adverse outcomes, declining to 60% for long-term outcome. There was greater enthusiasm for its use in patients with known coronary artery disease (87%) than in patients with risk factors only (72%). Although 66% considered it efficacious in vascular surgery, only 30% were convinced it was for nonvascular surgery (with a similar distribution for safety in these settings). Preoperative use was favored (94%), with most physicians favoring use within 1 week of surgery (52%). Most favored 1 to 2 weeks of postoperative therapy (43%), with the remainder favoring shorter (19%) or longer (35%) durations. Although 71% of clinicians reported frequent use in their practice, most believed its use was largely informal by their colleagues (83%) and rarely based on a formal clinical pathway (13%).

CONCLUSION

A wide range of opinions by clinicians regarding the efficacy, safety, and logistics of perioperative beta-adrenergic blockade was encountered, suggesting need for additional clinical research and centralized efforts at increasing compliance with existing guidelines.

Risk for stroke after elective noncarotid vascular surgery

INTRODUCTION

Patients undergoing operations to treat peripheral vascular disease have systemic atherosclerosis and are at risk for stroke. However, the incidence and effect of cerebrovascular events on noncarotid vascular surgical outcomes are not well-defined.

METHODS

Patients undergoing common operations for vascular disease from 1997 to 2000 were examined with data from the Veterans Affairs (VA) National Surgery Quality Improvement Project and the VA patient treatment files. Operations studied included abdominal aortic aneurysmectomy (n = 2551), aortobifemoral bypass (n = 2616), lower extremity bypass (n = 6866), and major lower extremity amputation (n = 7442). The incidence of perioperative stroke was determined, and logistic regression analysis was used to identify independent risk factors for stroke. Logistic and linear regression analyses were used to quantify the effect of postoperative stroke on adjusted mortality and length of stay. Odds ratio (OR) and 95% confidence interval (CI) were defined. P <.05 was considered significant.

RESULTS

Stroke was uncommon after noncarotid vascular procedures, occurring in only 0.4% to 0.6% of patients. Independent risk factors for stroke include preoperative ventilation (OR, 11; 95% CI, 5.0-22.3; P <.001), previous stroke or transient ischemic attack (OR, 4.2; 95% CI, 2.7-6.4; P <.001), postoperative myocardial infarction (OR, 3.3; 95% CI, 1.3-8.7; P =.009), and need to return to the operating room (OR, 2.2; 95% CI, 1.4-3.5; P =.001). Factors that did not appear to be associated with stroke risk included procedure type, diabetes, renal failure, dialysis dependence, number of transfused units of blood, and hypertension. After controlling for other postoperative complications and comorbid conditions, postoperative stroke significantly increased the risk for perioperative mortality (OR, 6.3; 95% CI, 3.4-11.4; P <.001), with similar magnitude as postoperative myocardial infarction (OR, 6.3; 95% CI, 3.9-10.1; P <.001). Stroke was also associated with a 48% increase in overall length of stay.

CONCLUSIONS

Stroke after noncarotid peripheral vascular surgery is uncommon, but results in markedly increased mortality and length of stay. Stroke risk is most strongly associated with previous stroke history and greater degree of illness. Patients with these associated conditions deserve particular attention to assessing and medically managing modifiable risk factors.

Variation in postoperative complication rates after high-risk surgery in the United States

OBJECTIVE

Our goal was to characterize variation in complication rates across hospitals with differing volumes for select high-risk operations in the United States.

METHODS

Data from the Nationwide Inpatient Sample for 1996 and 1997 were analyzed for 3 high-risk operations: esophagectomy (n=1,226), pancreatectomy (n=4,789), and intact abdominal aortic aneurysm repair (n=11,863). Complications evaluated included aspiration, cardiac complications, infection, pneumonia, pulmonary failure, renal failure, septicemia, and others. The risk of complications was calculated by hospital volume deciles, as well as for high-volume hospitals (HVH) and low-volume hospitals (LVH) defined by median hospital volume.

RESULTS

Rates of any postoperative complication varied nearly 2-fold across hospital volume groups. The proportion of patients across hospital deciles having at least one complication ranged from 30% to 51% for esophageal resection, 6% to 12% for pancreatic resection, and 9% to 18% for abdominal aortic aneurysm repair. HVH had lower rates of one or more complications after pancreatic resection (OR, 0.71; 95% CI, 0.57 to 0.83; P=.002), esophageal resection (OR, 0.68; 95% CI, 0.52 to 0.90; P=.008), and intact abdominal aortic aneurysm (AAA) repair (OR, 0.67; 95% CI, 0.59 to 0.76; P<.001). Patients with one or more complications after pancreatic resection had a mortality of 18.8% versus only 5.2% for those without complications (P<.001). Esophageal resection mortality was 16.9% for patients with at least one complication and 2.5% for those without complications (P<.001) and AAA repair mortality was 10.4% for patients with at least one complication and 2.9% for those without complications (P<.001).

CONCLUSIONS

High-risk operations have a decreased rate of postoperative complications when performed at HVH. Variation in complication rates may contribute to the volume-outcome relationship and provide a focus for quality improvement at LVH.

Operative mortality in colorectal cancer: prospective national study

OBJECTIVE

To develop a mathematical model that will predict the probability of death after surgery for colorectal cancer.

DESIGN

Descriptive study using routinely collected clinical data.

DATA SOURCE

The database of the Association of Coloproctology of Great Britain and Ireland (ACPGBI), encompassing 8077 patients with a new diagnosis of colorectal cancer in 73 hospitals during a 12 month period.

STATISTICAL ANALYSIS

A three level hierarchical logistic regression model was used to identify independent predictors of operative mortality. The model was developed on 60% of the patient population and its validity tested on the remaining 40%.

RESULTS

Overall postoperative mortality was 7.5% (95% confidence interval 6.9% to 8.1%). Independent predictors of death were age, American Society of Anesthesiology (ASA) grade, Dukes's stage, urgency of the operation, and cancer excision. When tested the predictive model showed good discrimination (area under the receiver operating characteristic curve = (0.775) and calibration (comparison of observed with expected mortality across different procedures; Hosmer-Lemeshow statistic = 6.34, 8 df, P = 0.610).

CONCLUSIONS

Clinicians can predict postoperative death by using a simple numerical table derived from the statistical model of the ACPGBI. The model can be used in everyday practice for preoperative counselling of patients and their carers as a part of multidisciplinary care. It may also be used to compare the outcomes between multidisciplinary teams for colorectal cancer.

The Leapfrog volume criteria may fall short in identifying high-quality surgical centers

OBJECTIVE

The original Leapfrog Initiative recommends selective referral based on procedural volume thresholds (500 coronary artery bypass graft [CABG] surgeries, 30 abdominal aortic aneurysm [AAA] repairs, 100 carotid endarterectomies [CEA], and 7 esophagectomies annually). We tested the volume-mortality relationship for these procedures in the University HealthSystem Consortium (UHC) Clinical DatabaseSM, a database of all payor discharge abstracts from UHC academic medical center members and affiliates. We determined whether the Leapfrog thresholds represent the optimal cutoffs to discriminate between high- and low-mortality hospitals.

METHODS

Logistic regression was used to test whether volume was a significant predictor of mortality. Volume was analyzed in 3 different ways: as a continuous variable, a dichotomous variable (above and below the Leapfrog threshold), and a categorical variable. We examined all possible thresholds for volume and observed the optimal thresholds at which the odds ratio is the highest, representing the greatest difference in odds of death between the 2 groups of hospitals.

RESULTS

In multivariate analysis, a relationship between volume and mortality exists for AAA in all 3 models. For CABG, there is a strong relationship when volume is tested as a dichotomous or categorical variable. For CEA and esophagectomy, we were unable to identify a consistent relationship between volume and outcome. We identified empirical thresholds of 250 CABG, 15 AAA, and 22 esophagectomies, but were unable to find a meaningful threshold for CEA.

CONCLUSIONS

In this group of academic medical centers and their affiliated hospitals, we demonstrated a significant relationship between volume and mortality for CABG and AAA but not for CEA and esophagectomy, based on the Leapfrog thresholds. We described a new methodology to identify optimal data-based volume thresholds that may serve as a more rational basis for selective referral.

Preoperative risks and outcomes of hip and knee arthroplasty in the Veterans Health Administration

The relationship between patient characteristics and outcomes of total joint arthroplasty (TJA) was examined in a population of veterans treated in VA hospitals. Outcomes included 30-day mortality and morbidity, postoperative length of stay, and readmission caused by surgical complications. A larger proportion of women then men were functionally impaired before surgery in both the hip (22% vs. 14%) and knee samples (14% vs. 7%; all P<.01). Rates of adverse outcomes in this population were very low. Preoperative comorbid conditions, abnormal laboratory values, and being nonwhite were related to poor outcomes of TJA. Gender was a significant independent predictor of morbidity and length of stay for total knee arthroplasty.

Towards a national clinical minimum data set for general surgery

Background

Measurement and comparison of surgical performance is accepted as necessary and inevitable. Risk-stratified (case-mix adjusted) models of clinical outcomes form a metric with which to assess performance, but require accurate data. Collecting such data in the clinical environment is time consuming and difficult. This study aimed to construct effective models, for operative and non-operative admissions, from routine clinical data residing in hospital computers, so minimizing data collection and quality problems, and facilitating national implementation.

Methods

Data for 3181 non-operative emergency, 5039 elective and 3043 emergency operative admissions for the 2 years beginning 1 August 1997 were used to generate logistic regression equations for risk of death, which were applied prospectively to the following 3 years' data.

Results

The models use urea, haemoglobin, white blood cell count, sodium, potassium, age on admission, sex, British United Provident Association (BUPA) Operative Severity Score (for operative admissions) and, implicitly, mode of admission and mortality at discharge. All three models successfully stratified risk into five or more bands.

Conclusion

Effective models of mortality, applicable to all general surgical admissions, can be constructed from existing routine clinical data, largely obtained from a single venesection. The data set is a candidate national clinical minimum data set.

Risk factors for adverse outcomes after the surgical treatment of appendicitis in adults

OBJECTIVE

To define risk factors that predict adverse outcomes after the surgical treatment of appendicitis in Department of Veterans Affairs Medical Centers.

SUMMARY BACKGROUND DATA

Risk factors for adverse outcomes after the surgical treatment of appendicitis in adults are poorly defined. Accurate presurgical assessment of the risk of perioperative complications and death is important in planning surgical therapy.

METHODS

The VA National Surgical Quality Improvement Program contains prospectively collected and extensively validated data on approximately 1,000,000 major surgical operations. All patients undergoing surgical intervention for appendicitis from 1991 to 1999 registered in this database were selected for study. Independent variables examined included 68 putative preoperative risk factors and 12 intraoperative process measures. Dependent variables were 21 specific adverse outcomes, including death. Stepwise logistic regression analysis was used to construct models predicting 30-day morbidity rate and the 30-day postoperative mortality rate.

RESULTS

There were 4163 patients identified. The mean age was 50 years; 96% were male. Sixteen percent of patients had 1 or more complications after surgical intervention. Prolonged ileus, failure to wean from the ventilator, pneumonia, and both superficial and deep wound infection were the most frequently reported complications, accounting for the majority of the morbidity. The 30-day mortality rate was 1.8% (74 deaths). For >50% of the complications reported, the 30-day mortality rates were significantly higher (P < 0.01) for patients with complications than for those without. Thirty-day mortality rates for several complications exceeded 30%, including cardiac arrest, coma >24 hours, myocardial infarction, acute renal failure, bleeding requiring >4 units of red cells, and systemic sepsis. Four preoperative factors predicted a high risk of 30-day mortality in the logistic regression analysis: "completely dependent" functional status, bleeding disorder, steroid usage, and current pneumonia. "Threat to life" or "moribund" American Society of Anesthesiologists classification and more than a 10% weight loss in the 6 months before surgery were associated with a high risk of complications.

CONCLUSIONS

Morbidity and mortality rates after the surgical treatment of appendicitis in VA hospitals are comparable with those reported in other large series. Most postsurgical complications are associated with an increased 30-day mortality rate. The models presented here are the most robust available in predicting 30-day morbidity and mortality for VA patients with appendicitis. Furthermore, they provide a starting point for the design of similar models to evaluate non-VA patients with appendicitis using the data the National Surgical Quality Improvement Program is currently gathering from private hospitals.

Using volume criteria: do California hospitals measure up?

BACKGROUND

Many studies have demonstrated a significant relationship between high procedural volume and better outcomes. As the public becomes increasingly aware of this medical literature, consumer groups have collaborated with medical researchers to operationalize this body of evidence. One such organization, the Leapfrog Group, has proposed annual volume criteria for four operations: coronary bypass grafting (CABG), abdominal aortic aneurysm (AAA), carotid endarterectomy (CEA), and esophageal cancer resection (ECR). This study analyzes California hospitals within the context of these volume criteria.

MATERIALS AND METHODS

Using the California inpatient database from 2000, we identified all CABG, AAA, CEA, and ECR operations performed at metropolitan hospitals. The volume of each of the four operations was tabulated by hospital and evaluated. Comparisons were made between academic and nonacademic hospitals.

RESULTS

Most hospitals in California did not meet Leapfrog's volume criteria. Only 2 hospitals of 287 (0.7%) met the volume criteria for the operations that it performed. Of the 71 (25%) hospitals that performed all four procedures, none met the volume criteria of all four procedures. In fact, only 10% of California hospitals performing these operations were high-volume hospitals based on Leapfrog's volume criteria. When comparing academic to nonacademic hospitals, academic hospitals performed more AAA operations than nonacademic hospitals (36 vs 12, P = 0.02). Although academic hospitals tended to have higher caseloads for CABG, CEA, and ECR, these did not reach statistical significance. Also, academic hospitals were more likely to be high volume for AAA (43.8% vs 7.0%, P < 0.01) and for ECR (23.1% vs 4.0%, P < 0.01).

CONCLUSIONS

California's hospital system is far from being regionalized. Although academic hospitals appear better positioned than nonacademic hospitals, the vast majority of all hospitals do not meet Leapfrog's volume criteria. As efforts to use volume as a proxy measure of quality gain momentum, hospitals and physicians will be forced to measure and report quality. As such, surgeons need to decide between accepting volume as an adequate measure of quality and developing other possibly more direct and reliable methods.

Automated intensive care unit risk adjustment: results from a National Veterans Affairs study

CONTEXT

Comparison of outcome among intensive care units (ICUs) requires risk adjustment for differences in severity of illness and risk of death at admission to the ICU, historically obtained by costly chart review and manual data entry.

OBJECTIVE

To accurately estimate patient risk of death in the ICU using data easily available in hospital electronic databases to permit automation.

DESIGN AND SETTING

Cohort study to develop and validate a model to predict mortality at hospital discharge using multivariate logistic regression with a split derivation (17,731) and validation (11,646) sample formed from 29,377 consecutive first ICU admissions to medical, cardiac, and surgical ICUs in 17 Veterans' Health Administration hospitals between February 1996 and July 1997.

MAIN OUTCOME MEASURES

Mortality at hospital discharge adjusted for age, laboratory data, diagnosis, source of ICU admission, and comorbid illness.

RESULTS

The overall hospital death rate was 11.3%. In the validation sample, the model separated well between survivors and nonsurvivors (area under the receiver operating characteristic curve = 0.885). Examination of the observed vs. the predicted mortality across the range of mortality showed the model was well calibrated.

CONCLUSIONS

Automation could broaden access to risk adjustment of ICU outcomes with only a small trade-off in discrimination. Broader use might promote valid evaluation of ICU outcomes, encouraging effective practices and improving ICU quality.

Differences in operative mortality between high- and low-volume hospitals in Ontario for 5 major surgical procedures: estimating the number of lives potentially saved through regionalization

BACKGROUND

Previous research has shown that persons undergoing certain high-risk surgical procedures at high-volume hospitals (HVHs) have a lower risk of postoperative death than those undergoing surgery at low-volume hospitals (LVHs). We estimated the absolute number of operative deaths that could potentially be avoided if 5 major surgical procedures in Ontario were restricted to HVHs.

METHODS

We collected data on all persons who underwent esophagectomy (613), colon or rectal resection for colorectal cancer (18 898), pancreaticoduodenectomy (686), pulmonary lobectomy or pneumonectomy for lung cancer (5156) or repair of an unruptured abdominal aortic aneurysm (AAA) (6279) in Ontario from Apr. 1, 1994, to Mar. 31, 1999. We calculated the excess number of operative deaths (defined as deaths in the period from the day of the operation to 30 days thereafter), adjusted for age, sex and comorbidity, among the 75% of persons treated in LVHs, as compared with the 25% treated in the highest-volume quartile of hospitals. Bootstrap methods were used to estimate 95% confidence intervals (CIs).

RESULTS

Of the 31 632 persons undergoing any of the 5 procedures, 1341 (4.24%) died within 30 days of surgery. If the 75% of persons treated at the LVHs had instead been treated at the HVHs, the annual number of lives potentially saved would have been 4 (95% CI, 0 to 9) for esophagectomy, 6 (95% CI, 1 to 11) for pancreaticoduodenectomy, 1 (95% CI, -10 to 13) for major lung resection and 14 (95% CI, 1 to 25) for repair of unruptured AAA. For resection of colon or rectum, the regionalization strategy would not have saved any lives, and 17 lives (95% CI, 36 to -3) would potentially have been lost.

INTERPRETATION

A small number of operative deaths are potentially avoidable by performing 4 of 5 complex surgical procedures only at HVHs in Ontario. In determining health policy, the most compelling argument for regionalizing complex surgical procedures at HVHs may not be the prevention of a large number of such deaths.

Transthoracic versus transhiatal esophagectomy: a prospective study of 945 patients

OBJECTIVE

Debate continues as to whether transhiatal esophagectomy results in lower morbidity and mortality than transthoracic esophagectomy. Most data addressing this issue are derived from single-institution studies. To investigate this question from a nationwide multicenter perspective, we used the Veterans Administration National Surgical Quality Improvement Program to prospectively analyze risk factors for morbidity and mortality in patients undergoing transthoracic esophagectomy or transhiatal esophagectomy from 1991 to 2000.

METHODS

Univariate and multivariate analyses were performed on 945 patients (mean age, 63 +/- 10 years). There were 562 transthoracic esophagectomies and 383 transhiatal esophagectomies in 105 hospitals, with complete 30-day outcomes recorded.

RESULTS

There were no differences in recorded preoperative variables between the groups that might bias any comparisons. Overall mortality was 10.0% (56/562) for transthoracic esophagectomy and 9.9% (38/383) for transhiatal esophagectomy (P =.983). Morbidity occurred in 47% (266/562) of patients after transthoracic esophagectomy and in 49% (188/383) of patients after transhiatal esophagectomy (P =.596). Risk factors for mortality common to both groups included a serum albumin value of less than 3.5 g/dL, age greater than 65 years, and blood transfusion of greater than 4 units (P <.05). When comparing transthoracic esophagectomy with transhiatal esophagectomy, there was no difference in the incidence of respiratory failure, renal failure, bleeding, infection, sepsis, anastomotic complications, or mediastinitis. Wound dehiscence occurred in 5% (18/383) of patients undergoing transhiatal esophagectomy and only 2% (12/562) of patients undergoing transthoracic esophagectomy (P =.036).

CONCLUSIONS

These data demonstrate no significant differences in preoperative variables and postoperative mortality or morbidity between transthoracic esophagectomy and transhiatal esophagectomy on the basis of a 10-year, prospective, multi-institutional, nationwide study.

Impact of renal insufficiency on short-term morbidity and mortality after lower extremity revascularization: data from the Department of Veterans Affairs' National Surgical Quality Improvement Program

Few data are available on the impact of renal insufficiency on short-term operative outcomes after lower extremity surgical revascularization. We used prospectively collected data from the Department of Veterans Affairs' National Surgical Quality Improvement Program (NSQIP) to explore the association with renal dysfunction of adverse outcomes occurring within 30 d of lower extremity surgical revascularization in a cohort of all patients undergoing at least one lower extremity surgical revascularization from 1/1/94 to 9/30/01 (n = 18,217). Even moderate renal insufficiency (estimated GFR 30-59cc/min/1.73m(2)) was associated with an increased incidence of postoperative death (adjusted odds ratio (OR) 1.44, 95% confidence interval (CI), 1.17 to 1.77, P = 0.001), cardiac arrest (OR 1.43, CI 1.09 to 1.88, P = 0.011), myocardial infarction (OR 1.68, 1.39 to 2.16, P < 0.001), unplanned intubation (OR 1.69, CI 1.39 to 2.07, P < 0.001) and prolonged intubation (OR 1.57, CI 1.28 to 1.94, P < 0.001) within 30 d of lower extremity revascularization. However, the incidence of wound infection and graft failure requiring return to the operating room did not appear to be substantially higher in this group. Our data also show that patients with renal insufficiency undergoing revascularization were more likely to require distal procedures and to present with limb-threatening infection compared to those with normal renal function. Efforts to improve pre-and post-operative care in patients with renal insufficiency undergoing lower extremity revascularization should take into account the increased incidence of postoperative death and cardiopulmonary complications in this group in addition to more traditional concerns about operative site complications. Further studies are needed to explore reasons for the higher rate of limb-threatening infection in patients with renal insufficiency undergoing revascularization.