Hospital Volume and Operative Mortality for General Surgery Operations Performed Emergently in Adults.

OBJECTIVE: This study aimed to answer 2 questions: first, to what degree does hospital operative volume affect mortality for adult patients undergoing 1 of 10 common emergency general surgery (EGS) operations? Second, at what hospital operative volume threshold will nearly all patients undergoing an emergency operation realize the average mortality risk? BACKGROUND: Nontrauma surgical emergencies are an underappreciated public health crisis in the United States; redefining where such emergencies are managed may improve outcomes. The field of trauma surgery established regionalized systems of care in part because studies demonstrated a clear relationship between hospital volume and survival for traumatic emergencies. Such a relationship has not been well-studied for nontrauma surgical emergencies. METHODS: Retrospective cohort study of all acute care hospitals in California performing nontrauma surgical emergencies. We employed a novel use of an ecological analysis with beta regression to investigate the relationship between hospital operative volume and mortality. RESULTS: A total of 425 acute care hospitals in California performed 165,123 EGS operations. Risk-adjusted mortality significantly decreased as volume increased for all 10 EGS operations (P < 0.001 for each); the relative magnitude of this inverse relationship differed substantially by procedure. Hospital operative volume thresholds were defined and varied by operation: from 75 cases over 2 years for cholecystectomy to 7 cases for umbilical hernia repair. CONCLUSIONS: Survival rates for nontrauma surgical emergencies were improved when operations were performed at higher-volume hospitals. The use of ecological analysis is widely applicable to the field of surgical outcomes research.

Hospital Variation in Geriatric Surgical Safety for Emergency Operation.

BACKGROUND: The American College of Surgeons maintains that surgical care in the US has not reached optimal safety and quality. This can be driven partially by higher-risk, emergency operations in geriatric patients. We therefore sought to answer 2 questions: First, to what degree does standardized postoperative mortality vary in hospitals performing nonelective operations in geriatric patients? Second, can the differences in hospital-based mortality be explained by patient-, operative-, and hospital-level characteristics among outlier institutions? STUDY DESIGN: Patients 65 years and older who underwent 1 of 8 common emergency general surgery operations were identified using the California State Inpatient Database (2010 to 2011). Expected mortality was obtained from hierarchical, Bayesian mixed-effects logistic regression models. A risk-adjusted hospital-level standardized mortality ratio (SMR) was calculated from observed-to-expected in-hospital deaths. "Outlier" hospitals had an SMR 80% CI that did not cross the mean SMR of 1.0. High-mortality (SMR >1.0) and low-mortality (SMR <1.0) outliers were compared. RESULTS: We included 24,207 patients from 107 hospitals. SMRs varied widely, from 2.3 (highest) to 0.3 (lowest). Eleven hospitals (10.3%) were poor-performing high-SMR outliers, and 10 hospitals (9.3%) were exceptional-performing low-SMR outliers. SMR was 3 times worse in the high-SMR compared with the low-SMR group (1.7 vs 0.6; p < 0.001). Patient-, operation-, and hospital-level characteristics were equivalent among outlier-hospitals. CONCLUSIONS: Significant hospital variation exists in standardized mortality after common general surgery operations done emergently in older patients. More than 10% of institutions have substantial excess mortality. These findings confirm that the safety of emergency operation in geriatric patients can be significantly improved by decreasing the wide variability in mortality outcomes.

Regionalization of emergency general surgery operations: A simulation study.

BACKGROUND: It has been theorized that a tiered, regionalized system of care for emergency general surgery (EGS) patients-akin to regional trauma systems-would translate into significant survival benefits. Yet data to support this supposition are lacking. The aim of this study was to determine the potential number of lives that could be saved by regionalizing EGS care to higher-volume, lower-mortality EGS institutions. METHODS: Adult patients who underwent one of 10 common EGS operations were identified in the California Inpatient Database (2010-2011). An algorithm was constructed that "closed" lower-volume, higher-mortality hospitals and referred those patients to higher-volume, lower-mortality institutions ("closure" based on hospital EGS volume-threshold that optimized to 95% probability of survival). Primary outcome was the number of lives saved. Fifty thousand regionalization simulations were completed (5,000 for each operation) employing a bootstrap resampling method to proportionally redistribute patients. Estimates of expected deaths at the higher-volume hospitals were recalculated for every bootstrapped sample. RESULTS: Of the 165,123 patients who underwent EGS operations over the 2-year period, 17,655 (10.7%) were regionalized to a higher-volume hospital. On average, 128 (48.8%) of lower-volume hospitals were "closed," ranging from 68 (22.0%) hospital closures for appendectomy to 205 (73.2%) for small bowel resection. The simulations demonstrated that EGS regionalization would prevent 9.7% of risk-adjusted EGS deaths, significantly saving lives for every EGS operation: from 30.8 (6.5%) deaths prevented for appendectomy to 122.8 (7.9%) for colectomy. Regionalization prevented 4.6 deaths per 100 EGS patient-transfers, ranging from 1.3 for appendectomy to 8.0 for umbilical hernia repair. CONCLUSION: This simulation study provides important new insight into the concept of EGS regionalization, suggesting that 1 in 10 risk-adjusted deaths could be prevented by a structured system of EGS care. Future work should expand upon these findings using more complex discrete-event simulation models. LEVEL OF EVIDENCE: Therapeutic/Care Management, level IV.

High-performance acute care hospitals: Excelling across multiple emergency general surgery operations in the geriatric patient.

BACKGROUND: As the geriatric population grows, the need for hospitals performing high quality emergency general surgery (EGS) on older patients will increase. Identifying clusters of high-performing geriatric emergency general surgery hospitals would substantiate the need for in-depth analyses of hospital-specific structures and practices that benefit older EGS patients. The objectives of this study were therefore to identify clusters of hospitals based on mortality performance for geriatric patients undergoing common EGS operations and to determine if hospital performance was similar for all operation types. METHODS: Hospitals in the California State Inpatient Database were included if they performed a range of eight common EGS operations in patients 65 years or older, with a minimum requirement of three of each operation performed over 2 years. Multivariable beta regression models were created to define hospital-level risk-adjusted mortality. Centroid cluster analysis was used to identify groups of hospitals based on mortality and to determine if mortality-performance differed by operation. RESULTS: One hundred seven hospitals were included, performing a total of 24,279 operations in older patients. Hospitals separated into three distinct clusters: high, average, and low performers. The high-performing hospitals had survival rates 1 to 2 standard deviations better than the low-performers (p < 0.001). For each cluster, high performance in any one EGS operation consistently translated into high performance across all EGS operations. CONCLUSION: Hospitals conducting EGS operations in the geriatric patient population cluster into three distinct groups based on their survival performance. High-performing hospitals significantly outperform the average and low performers across every operation. The high-performers achieve reliable, high-quality results regardless of operation type. Further qualitative research is needed to investigate the perioperative drivers of hospital performance in the geriatric EGS population. LEVEL OF EVIDENCE: Study Type Prognostic, level III.

Top-tier emergency general surgery hospitals: Good at one operation, good at them all.

BACKGROUND: There is a longstanding interest in the field of management science to study high performance organizations. Applied to medicine, research on hospital performance indicates that some hospitals are high performing, while others are not. The objective of this study was to identify a cluster of high-performing emergency general surgery (EGS) hospitals and assess whether high performance at one EGS operation was associated with high performance on all EGS operations. METHODS: Adult patients who underwent one of eight EGS operations were identified in the California State Inpatient Database (2010-2011), which we linked to the American Hospital Association database. Beta regression was used to estimate a hospital's risk-adjusted mortality, accounting for patient- and hospital-level factors. Centroid cluster analysis grouped hospitals by patterns of mortality rates across the eight EGS operations using z scores. Multinomial logistic regression compared hospital characteristics by cluster. RESULTS: A total of 220 acute care hospitals were included. Three distinct clusters of hospitals were defined based on assessment of mortality for each operation type: high-performing hospitals (n = 66), average performing (n = 99), and low performing (n = 55). The mortality by individual operation type at the high-performing cluster was consistently at least 1.5 standard deviations better than the low-performing cluster (p < 0.001). Within-cluster variation was minimal at high-performing hospitals compared with wide variation at low-performing hospitals. A hospital's high performance in one EGS operation type predicted high performance on all EGS operation types. CONCLUSION: High-performing EGS hospitals attain excellence across all types of EGS operations, with minimal variability in mortality. Poor-performing hospitals are persistently below average, even for low-risk operations. These findings suggest that top-performing EGS hospitals are highly reliable, with systems of care in place to achieve consistently superior results. Further investigation and collaboration are needed to identify the factors associated with high performance. LEVEL OF EVIDENCE: Prognostic, level III.

Hospital Operative Volume as a Quality Indicator for General Surgery Operations Performed Emergently in Geriatric Patients

BACKGROUND: Within the growing geriatric population, there is an increasing need for emergency operations. Optimizing outcomes can require a structured system of surgical care based on key quality indicators. To investigate this, the current study sought to answer 2 questions. First, to what degree does hospital emergency operative volume impact mortality for geriatric patients undergoing emergency general surgery (EGS) operations? Second, at what procedure-specific hospital volume will geriatric patients undergoing an emergency operation achieve at or better than average mortality risk? STUDY DESIGN: Retrospective cohort study of geriatric patients (aged 65 years and older) who underwent 1 of 10 EGS operations identified from the California State Inpatient Database (2010 to 2011). ß-Logistic generalized linear regression was used, with the hospital as the unit of analysis, to investigate the relationship between hospital operative volume and in-hospital riskv-adjusted mortality. Hospital operative volume thresholds to optimize probability of survival were defined. RESULTS: There were 41,860 operations evaluated at 299 hospitals. For each operation, mortality decreased as hospital emergency operative volume increased (p < 0.001 for each operation); for every standardized increase in volume (meaning +1 natural logarithm of volume), the reduction in mortality ranged from 14% for colectomy to 61% for appendectomy. Hospital volume thresholds, which optimize to 95% probability of survival, varied by procedure, with a mean of 14 operations over 2 years. More than 50% of hospitals did not meet the threshold benchmarks, representing 22% of patients. CONCLUSIONS: Survival rates for geriatric patients were improved substantially when emergency operations were performed at hospitals with higher operative volumes. Consistent with all active Quality Programs of the American College of Surgeons, hospital operative volume appears to be an important metric of surgical quality for older patients undergoing emergency operations.

Evaluating mortality outlier hospitals to improve the quality of care in emergency general surgery.

BACKGROUND: Expected performance rates for various outcome metrics are a hallmark of hospital quality indicators used by Agency of Healthcare Research and Quality, Center for Medicare and Medicaid Services, and National Quality Forum. The identification of outlier hospitals with above- and below-expected mortality for emergency general surgery (EGS) operations is therefore of great value for EGS quality improvement initiatives. The aim of this study was to determine hospital variation in mortality after EGS operations, and compare characteristics between outlier hospitals. METHODS: Using data from the California State Inpatient Database (2010-2011), we identified patients who underwent one of eight common EGS operations. Expected mortality was obtained from a Bayesian model, adjusting for both patient- and hospital-level variables. A hospital-level standardized mortality ratio (SMR) was constructed (ratio of observed to expected deaths). Only hospitals performing three or more of each operation were included. An "outlier" hospital was defined as having an SMR with 80% confidence interval that did not cross 1.0. High- and low-mortality SMR outliers were compared. RESULTS: There were 140,333 patients included from 220 hospitals. Standardized mortality ratio varied from a high of 2.6 (mortality, 160% higher than expected) to a low of 0.2 (mortality, 80% lower than expected); 12 hospitals were high SMR outliers, and 28 were low SMR outliers. Standardized mortality was over three times worse in the high SMR outliers compared with the low SMR outliers (1.7 vs. 0.5; p < 0.001). Hospital-, patient-, and operative-level characteristics were equivalent in each outlier group. CONCLUSION: There exists significant hospital variation in standardized mortality after EGS operations. High SMR outliers have significant excess mortality, while low SMR outliers have superior EGS survival. Common hospital-level characteristics do not explain the wide gap between underperforming and overperforming outlier institutions. These findings suggest that SMR can help guide assessment of EGS performance across hospitals; further research is essential to identify and define the hospital processes of care which translate into optimal EGS outcomes. LEVEL OF EVIDENCE: Epidemiologic Study, level III.