Amir A. Ghaferi

Variation in hospital mortality associated with inpatient surgery.

BACKGROUND Hospital mortality that is associated with inpatient surgery varies widely. Reducing rates of postoperative complications, the current focus of payers and regulators, may be one approach to reducing mortality. However, effective management of complications once they have occurred may be equally important. METHODS We studied 84,730 patients who had undergone inpatient general and vascular surgery from 2005 through 2007, using data from the American College of Surgeons National Surgical Quality Improvement Program. We first ranked hospitals according to their risk-adjusted overall rate of death and divided them into five groups. For hospitals in each overall mortality quintile, we then assessed the incidence of overall and major complications and the rate of death among patients with major complications. RESULTS Rates of death varied widely across hospital quintiles, from 3.5% in very-low-mortality hospitals to 6.9% in very-high-mortality hospitals. Hospitals with either very high mortality or very low mortality had similar rates of overall complications (24.6% and 26.9%, respectively) and of major complications (18.2% and 16.2%, respectively). Rates of individual complications did not vary significantly across hospital mortality quintiles. In contrast, mortality in patients with major complications was almost twice as high in hospitals with very high overall mortality as in those with very low overall mortality (21.4% vs. 12.5%, P<0.001). Differences in rates of death among patients with major complications were also the primary determinant of variation in overall mortality with individual operations. CONCLUSIONS In addition to efforts aimed at avoiding complications in the first place, reducing mortality associated with inpatient surgery will require greater attention to the timely recognition and management of complications once they occur.

Complications, failure to rescue, and mortality with major inpatient surgery in medicare patients.

Objective:We sought to determine whether hospital variations in surgical mortality were due to differences in complication rates or failure to rescue rates (ie, case-fatality rates in patients with a complication). Background:Wide variations in mortality after major surgery are becoming increasingly apparent. The clinical mechanisms underling these variations are largely unexplored. Methods:We studied all Medicare beneficiaries undergoing 6 major operations in 2005 to 2006: pancreatectomy, esophagectomy, abdominal aortic aneurysm repair, coronary artery bypass grafting, aortic valve replacement, and mitral valve replacement. We ranked hospitals according to risk-adjusted mortality and divided them into 5 equal groups. We then compared the incidence of complications and rates of failure to rescue between the top 20% of hospitals (“best”) and bottom 20% of hospitals (“worst”). Analyses were conducted for all operations combined and for each individual procedure. Results:For all 6 operations combined, the worst hospitals had mortality rates 2.5-fold higher than the best hospitals (8.0% vs. 3.0%). However, complication rates were similar at worst and best hospitals (36.4% vs. 32.7%). In contrast, failure to rescue rates were much higher at the worst compared with the best hospitals (16.7% vs. 6.8%). These findings persisted in analyses with individual operations and specific complications. Conclusions:Reducing variations in mortality will require strategies to improve the ability of high-mortality hospitals to manage postoperative complications.

Hospital volume and failure to rescue with high-risk surgery.

Introduction:Although the relationship between surgical volume and mortality is well established, the mechanisms underlying these associations remain uncertain. We sought to determine whether increased mortality at low-volume centers was due to higher complication rates or less success in rescuing patients from complications. Methods:Using 2005 to 2007 Medicare data, we identified patients undergoing 3 high-risk cancer operations: gastrectomy, pancreatectomy, and esophagectomy. We first ranked hospitals according to their procedural volume for these operations and divided them into 5 equal groups (quintiles) based on procedure volume cutoffs that most closely resulted in an equal distribution of patients through the quintiles. We then compared the incidence of major complications and “failure to rescue” (ie, case fatality among patients with complications) across hospital quintiles. We performed this analysis for all operations combined and for each operation individually. Results:With all 3 operations combined, failure to rescue had a much stronger relationship to hospital volume than postoperative complications. Very low-volume (lowest quintile) hospitals had only slightly higher complications rates (42.7% vs. 38.9%; odds ratio 1.17, 95% confidence interval, 1.02–1.33), but markedly higher failure-to-rescue rates (30.3% vs. 13.1%; odds ratio 2.89, 95% confidence interval, 2.40–3.48) compared with very high-volume hospitals (highest quintile). These relationships also held true for individual operations. For example, patients undergoing pancreatectomy at very low-volume hospitals were 1.7 times more likely to have a major complication than those at very high-volume hospitals (38.3% vs. 27.7%, P<0.05), but 3.2 times more likely to die once those complications had occurred (26.0% vs. 9.9%, P<0.05). Conclusions:Differences in mortality between high and low-volume hospitals are not associated with large differences in complication rates. Instead, these differences seem to be associated with the ability of a hospital to effectively rescue patients from complications. Strategies focusing on the timely recognition and management of complications once they occur may be essential to improving outcomes at low-volume hospitals.

Hospital volume and operative mortality in the modern era.

Objective:To determine whether the relationship between hospital volume and mortality has changed over time. Background:It is generally accepted that hospital volume is associated with mortality in high-risk procedures. However, as surgical safety has improved over the last decade, recent evidence has suggested that the inverse relationship has diminished or been eliminated. Methods:Using national Medicare claims data from 2000 through 2009, we examined mortality among 3,282,127 patients who underwent 1 of 8 gastrointestinal, cardiac, or vascular procedures. Hospitals were stratified into quintiles of operative volume. Using multivariable logistic regression models to adjust for patient characteristics, we examined the relationship between hospital volume and mortality, and assessed for changes over time. We performed sensitivity analyses using hierarchical logistic regression modeling with hospital-level random effects to confirm our results. Results:Throughout the 10-year period, a significant inverse relationship was observed in all procedures. In 5 of the 8 procedures studied, the strength of the volume-outcome relationship increased over time. In esophagectomy, for example, the adjusted odds ratio of mortality in very low volume hospitals compared to very high volume hospitals increased from 2.25 [95% confidence interval (CI): 1.57–3.23] in 2000–2001 to 3.68 (95% CI: 2.66–5.11) in 2008–2009. Only pancreatectomy showed a notable decrease in strength of the relationship over time, from 5.83 (95% CI: 3.64–9.36) in 2000–2001, to 3.08 (95% CI: 2.07–4.57) in 2008–2009. Conclusions:For all procedures examined, higher volume hospitals had significantly lower mortality rates than lower volume hospitals. Despite recent improvements in surgical safety, the strong inverse relationship between hospital volume and mortality persists in the modern era.

Hospital Characteristics Associated with Failure to Rescue from Complications after Pancreatectomy

BACKGROUND Failure to rescue (ie, mortality after a major complication) has recently been demonstrated as a mechanism underlying differences between high and low mortality hospitals. In this study, we sought to better understand the hospital characteristics that may explain failure to rescue. STUDY DESIGN Using data from the 2000 to 2006 Nationwide Inpatient Sample and the American Hospital Association annual survey, we evaluated the effect of 5 hospital level characteristics on failure to rescue (FTR) rates. Using multivariate logistic regression models, we determined the relative contribution of each of these factors to the FTR rates at the lowest and highest mortality hospitals. RESULTS Failure to rescue varied 6-fold across hospitals (6.4% in very low mortality hospitals vs 40.0% in very high mortality hospitals, p < 0.001). Several hospital characteristics were significantly associated with lower FTR: teaching status (odds ratio [OR] 0.66, 95% CI 0.53 to 0.82), hospital size greater than 200 beds (OR 0.65, 95% CI 0.48 to 0.87), average daily census greater than 50% capacity (OR 0.56, 95%CI 0.32 to 0.98), increased nurse-to-patient ratios (OR 0.94, 95% CI 0.89 to 0.99), and high hospital technology (OR 0.65, 95% CI 0.52 to 0.81). Including all hospital characteristics into a multivariate model results in a 36% reduction in the odds of FTR between very high and very low mortality hospitals (OR 6.6, 95% CI 3.7 to 11.9). CONCLUSIONS Several hospital characteristics are associated with FTR from major complications. However, a large portion of what makes some hospitals better than others at rescuing patients remains unexplained. Future research should focus on hospital cultures and attitudes that may contribute to the timely recognition and effective management of major complications.

Understanding the Volume-Outcome Effect in Cardiovascular Surgery: The Role of Failure to Rescue

IMPORTANCE To effectively guide interventions aimed at reducing mortality in low-volume hospitals, the underlying mechanisms of the volume-outcome relationship must be further explored. Reducing mortality after major postoperative complications may represent one point along the continuum of patient care that could significantly affect overall hospital mortality. OBJECTIVE To determine whether increased mortality at low-volume hospitals performing cardiovascular surgery is a function of higher postoperative complication rates or of less successful rescue from complications. DESIGN, SETTING, AND PARTICIPANTS We used patient-level data from 119434 Medicare fee-for-service beneficiaries aged 65 to 99 years undergoing coronary artery bypass grafting, aortic valve repair, or abdominal aortic aneurysm repair between January 1, 2005, and December 31, 2006. For each operation, we first divided hospitals into quintiles of procedural volume. We then assessed hospital risk-adjusted rates of mortality, major complications, and failure to rescue (ie, case fatality among patients with complications) within each volume quintile. EXPOSURE Hospital procedural volume. MAIN OUTCOMES AND MEASURES Hospital rates of risk-adjusted mortality, major complications, and failure to rescue. RESULTS For each operation, hospital volume was more strongly related to failure-to-rescue rates than to complication rates. For example, patients undergoing aortic valve replacement at very low-volume hospitals (lowest quintile) were 12% more likely to have a major complication than those at very high-volume hospitals (highest quintile) but were 57% more likely to die if a complication occurred. CONCLUSIONS AND RELEVANCE High-volume and low-volume hospitals performing cardiovascular surgery have similar complication rates but disparate failure-to-rescue rates. While preventing complications is important, hospitals should also consider interventions aimed at quickly recognizing and managing complications once they occur.

Racial/Ethnic Disparities in Access to Care and Survival for Patients With Early-Stage Hepatocellular Carcinoma

OBJECTIVE To determine whether controlling for differences in the use of invasive therapy affects racial/ethnic differences in survival of early-stage hepatocellular carcinoma (HCC). DESIGN A retrospective cohort study using Surveillance, Epidemiology, and End Results (SEER) HCC data. Invasive therapy was defined as tumor ablation, hepatectomy, or liver transplant. Race/ethnicity was defined as white, black, Asian, Hispanic, or other. Racial/ethnic differences in overall and treatment-adjusted survival were assessed using the Kaplan-Meier method and base- and treatment-stratified multivariable Cox proportional hazards models. PATIENTS All patients diagnosed as having stage I or II HCC from January 1, 1995, through December 31, 2006 (N = 13 244). SETTING Data were obtained from the National Cancer Institutes SEER registry. MAIN OUTCOME MEASURES Differences in survival by race/ethnicity accounting for the use of invasive therapy and treatment benefit. RESULTS Overall, 32.8% of patients received invasive therapy. We found higher mortality rates in the base survival model for black (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.15-1.33) and Hispanic (1.08; 1.01-1.15) patients and lower mortality rates in Asian patients (0.87; 0.82-0.93) compared with whites. After treatment stratification, compared with white patients, blacks had a 12% higher mortality rate (HR, 1.11; 95% CI, 1.03-1.20), Hispanics had a similar mortality rate (0.97; 0.91-1.04), and Asians had a 16% lower mortality rate (0.84; 0.79-0.89). CONCLUSIONS For early-stage HCC, racial/ethnic disparities in survival between minority and white patients are notable. After accounting for differences in stage, use of invasive therapy, and treatment benefit, no racial/ethnic survival disparity is evident between Hispanics and whites, but blacks have persistently poor survival.

Explaining Racial Disparities in Outcomes After Cardiac Surgery: The Role of Hospital Quality

IMPORTANCE Racial disparities in mortality rates after coronary artery bypass graft (CABG) surgery are well established. We have yet to fully understand how care at high-mortality, low-quality hospitals contributes to racial disparities in surgical outcomes. OBJECTIVE To determine the effects of hospital quality on racial disparities in mortality rates after CABG surgery. DESIGN, SETTING, AND PARTICIPANTS The national Medicare database (2007-2008) was used to identify 173,925 patients undergoing CABG surgery in US hospitals. MAIN OUTCOMES AND MEASURES Our primary measure of quality was the risk-adjusted mortality rate for each hospital. Logistic regression was used to determine the relationship between race and mortality rates, accounting for patient characteristics, socioeconomic status, and hospital quality. RESULTS Nonwhite patients had 33% higher risk-adjusted mortality rates after CABG surgery than white patients (odds ratio [OR], 1.33; 95% CI, 1.23-1.45). In hospitals treating the highest proportion of nonwhite patients (>17.7%), the mortality was 4.8% in nonwhite and 3.8% in white patients. When assessed independently, differences in hospital quality explained 35% of the observed disparity in mortality rates (OR, 1.22; 95% CI, 1.12-1.34). We were able to explain 53% of the observed disparity after adjusting for differences in socioeconomic status and hospital quality. However, even after these factors were taken into account, nonwhite patients had a 16% higher mortality (OR, 1.16; 95% CI, 1.05-1.27). CONCLUSIONS AND RELEVANCE Hospital quality contributes significantly to racial disparities in outcomes after CABG surgery. However, a significant fraction of this racial disparity remains unexplained. Efforts to decrease racial disparities in health care should focus on underperforming centers of care treating disproportionately high numbers of nonwhite patients.

Impact of Hospital Characteristics on Failure to Rescue Following Major Surgery.

Objective:To determine the effect of hospital characteristics on failure to rescue after high-risk surgery in Medicare beneficiaries. Summary Background Data:Reducing failure to rescue events is a common quality target for US hospitals. Little is known about which hospital characteristics influence this phenomenon and more importantly by how much. Methods:We identified 1,945,802 Medicare beneficiaries undergoing 1 of six high-risk general or vascular operations between 2007 and 2010. Using multilevel mixed-effects logistic regression modeling, we evaluated how failure to rescue rates were influenced by specific hospital characteristics previously associated with postsurgical outcomes. We used variance partitioning to determine the relative influence of patient and hospital characteristics on the between-hospital variability in failure to rescue rates. Results:Failure to rescue rates varied up to 11-fold between very high and very low mortality hospitals. Comparing the highest and lowest mortality hospitals, we observed that teaching status (range: odds ratio [OR] 1.08–1.54), high hospital technology (range: OR 1.08–1.58), increasing nurse-to-patient ratio (range: OR 1.02–1.14), and presence of >20 intensive care unit (ICU) beds (range: OR 1.09–1.62) significantly influenced failure to rescue rates for all procedures. When taken together, hospital and patient characteristics accounted for 12% (lower extremity revascularization) to 57% (esophagectomy) of the observed variation in failure to rescue rates across hospitals. Conclusions:Although several hospital characteristics are associated with lower failure to rescue rates, these macrosystem factors explain a small proportion of the variability between hospitals. This suggests that microsystem characteristics, such as hospital culture and safety climate, may play a larger role in improving a hospitals ability to manage postoperative complications.

Variation in Mortality After High-Risk Cancer Surgery Failure to Rescue

Surgical mortality with oncologic surgery varies widely in the United States. Patients, providers, and payers are paying closer attention to these variations and a way of reducing them. Although different hospital and surgical technologies and processes of care may account for some of this variation, there is an increasing awareness of the role of hospital safety culture. There is a growing body of evidence suggesting the importance of reducing mortality rates after major complications as a means to reducing the disparate mortality rates with oncologic surgery.