Impact of hospital volume on patient safety indicators and failure to rescue following open aortic aneurysm repair.

Failure to rescue (FTR), a patient safety indicator (PSI) defined, codified, and adjudicated by the Agency for Healthcare Research and Quality, is classified as a preventable inpatient death following major complications. FTR has been reported to be a significant driver of postoperative mortality after open abdominal aortic aneurysm (OAAA) repair. The association between hospital volume (HV) and mortality is well known; however, the mechanisms responsible for these improved outcomes and relative contribution to observed interhospital variation is poorly understood. Similarly, HV influence on specific complications predictive of FTR is unknown; therefore, we sought to determine how HV influences risk and contributes to interhospital variation in PSI events leading to FTR and/or in-hospital mortality after OAAA repair. The Vizient database (174 academic/nonacademic hospitals) was queried for all OAAA repairs (elective, n = 2827; nonelective, n = 1622) completed from 2012 to 2014. The primary endpoint was combined FTR and/or in-hospital 30-day mortality. Risk-adjusted rates of complications, Agency for Healthcare Research and Quality-designated PSIs, and FTR were determined. Additional modeling identified PSIs associated with FTR, whereas HV effects on PSIs and FTR were evaluated using mixed-effect models accounting for interhospital variation. Proportion of variation attributable to HV was estimated by contrasting hospital random effect variances in the presence/absence of volume effects. The combined overall FTR/in-hospital 30-day mortality rate was 9.3% (n = 414). For elective and nonelective cases, the overall FTR and 30-day mortality rates were: FTR, 1.6%, 4.9%; and 30-day in-hospital mortality, 3.4%, 17.5%, respectively. HV significantly influenced FTR/30-day in-hospital mortality (P < .0001). FTR/30-day mortality odds for hospitals with 3-year volumes of 50, 100, 150, and 200 cases were 1.4, 2.0, 2.7, and 3.0 times lower, respectively, than hospitals performing ≤25 cases/3 years. The proportion of interhospital variation attributed to HV was greatest for FTR/30-day mortality (62%). Procedural volume accounted for 41% and 38% of interhospital variation in postoperative bleeding and myocardial infarction, respectively. Preoperative predictors of FTR included coagulopathy, arrhythmia (nonelective cases); congestive heart failure, obesity (elective cases); and age, neurological disease, hypertension, and valvular disease (all cases). OAAA FTR/30-day in-hospital mortality strongly correlated with annual case volume with higher volume centers having the lowest risk. Notably, HV accounted for a significant proportion of the observed variation in FTR and specific complications providing direct evidence for how the volume-outcome relationship may influence perioperative mortality. These findings can inform stakeholders to strategically enable them to implement processes of care directed at the most vulnerable patients that are designed to reduce the likelihood of preventable adverse events and death after OAAA repair. Furthermore, these results underscore the need to regionalize OAAA repair and potentially other complex operations, to HV centers because of their improved ability to rescue patients experiencing complications associated with postoperative mortality.

Scali ST ，Giles KA ，Kubilis P ，Beck AW ，Crippen CJ ，Hughes SJ ，Huber TS ，Upchurch GR Jr ，Stone DH ... -  《-》

Association of hospital volume with patient selection, risk of complications, and mortality from failure to rescue after open abdominal aortic aneurysm repair.

The association of higher hospital volume with lower mortality after open abdominal aortic aneurysm (OAAA) repair is well known; however, the underlying mechanism for improved outcomes is poorly understood. Better patient selection, lower risk of complications, and improved ability to rescue patients after adverse events are assumed mechanisms, but few data exist to validate this hypothesis. The purpose of this analysis was to determine the association of hospital volume with patient selection, incidence of complications, and failure to rescue (FTR) after adverse events resulting from OAAA repair. The Vizient (Irving, Tex) database (>95% of all academic hospitals) was reviewed for OAAA repairs (elective, n = 2827; nonelective, n = 1622) performed from 2012 to 2014. Presentation type (elective vs nonelective) was considered in all analyses. Elixhauser comorbidity index and van Walraven weighted scores were assigned to patients and volume-outcome relationships explored. By use of logistic regression, risk-adjusted complications (including preventable complications; Agency for Healthcare Research and Quality patient safety indicators [PSIs]) and FTR rates were determined. Predicted risk scores were assigned to delineate hospital volume association with these outcomes. Overall, no relationship between hospital volume and composite patient comorbidity severity score was identified (Elixhauser comorbidity index and van Walraven weighted scores: Pearson [ρ, 0.02], P = .2; [ρ, -0.01], P = .4; Spearman correlation coefficient [ρ, 0.02], P = .4; [ρ, -0.02], P = .2). The lack of correlation persisted in considering elective vs nonelective status. However, for elective cases, differences in specific comorbidities were noted because high-volume hospitals were more likely to repair patients with a history of peripheral vascular disease (P = .01), diabetes (P = .07), obesity (P = .004), and alcohol abuse (P = .05). Lower volume hospitals more frequently repaired patients with hypothyroidism (P = .05), fluid and electrolyte disorders (P = .007), and chronic blood loss anemia (P = .05). No specific individual comorbidity differences were detected for nonelective cases. In examining hospital volume effects on the likelihood for development of any complication (45%), PSIs (12%), and FTR (9%), a significant risk reduction was noted in high-volume institutions. Specifically, a nonlinear relationship between hospital volume and risk of any complication (P = .0004), PSI (P = .0004), and FTR (P =. 0003) was present. In exploring the risk of specific complications or PSI events, greater hospital volume was strongly correlated to a lower likelihood of multiple adverse outcomes. Although high-volume institutions performing OAAA repair do not necessarily operate on patients with more comorbidities, there are important differences in the patients selected compared with lower volume hospitals. The risk for development of multiple specific postoperative complications as well as for preventable adverse events preceding FTR is significantly lower in high-volume centers. These findings provide benchmarks for multiple selected quality indicators and further support national initiatives to incentivize regionalization of OAAA care.

Giles KA ，Stone DH ，Beck AW ，Huber TS ，Upchurch GR Jr ，Arnaoutakis DJ ，Back MR ，Kubilis P ，Neal D ，Schermerhorn ML ，Scali ST ... -  《-》

Effects of hospital safety-net burden and hospital volume on failure to rescue after open abdominal aortic surgery.

Failure to rescue (FTR) is defined as the inability to rescue a patient from major perioperative complications, resulting in operative mortality. FTR is a known contributor to operative mortality after open abdominal aortic surgery. Understanding the causes of FTR is essential to designing interventions to improve perioperative outcomes. The objective of this study was to determine the relative contributions of hospital volume and safety-net burden (the proportion of uninsured and Medicaid-insured patients) to FTR. The Nationwide Inpatient Sample (2001-2011) was analyzed to investigate variables associated with FTR after elective open abdominal aortic operations in the United States. FTR was defined as in-hospital death following postoperative complications. Mixed multivariate regression models were used to assess independent predictors of FTR, taking into account the clustered structure of the data (patients nested into hospitals). A total of 47,233 elective open abdominal aortic operations were performed in 1777 hospitals during the study period. The overall incidences of postoperative complications, in-hospital mortality, and FTR in the whole cohort were 32.7%, 3.2%, and 8.6%, respectively. After adjusting for demographics, comorbidities, and hospital characteristics, safety-net burden was significantly associated with increased likelihood of FTR (highest vs lowest quartile of safety-net burden, odds ratio, 1.59; 95% confidence interval, 1.32-1.91; P < .0001). In contrast, after adjusting for safety-net burden, procedure-specific hospital volume was not significantly associated with FTR (P = .897). After adjusting for patient- and hospital-level variables, including hospital volume, safety-net burden was an independent predictor of FTR after open aortic surgery. Future investigations should be aimed at better understanding the relationship between safety-net hospital burden and FTR to design interventions to improve outcomes after open abdominal aortic surgery.

Rosero EB ，Joshi GP ，Minhajuddin A ，Timaran CH ，Modrall JG ... -  《-》

Failure to rescue and mortality following repair of abdominal aortic aneurysm.

Recently, failure to rescue (FTR; death following major complication) has been shown to be a primary driver of mortality in highly morbid operations. Establishing this relationship for open and endovascular repair of abdominal aortic aneurysms may be a critical first step in improving mortality following these procedures. We sought to examine the relative contribution of severe complications and FTR to variations in mortality rate. We examined endovascular aortic repair (EVAR) and open aortic repair (OAR; n = 3215) performed in 40 hospitals participating in the Michigan Surgical Quality Collaborative from 2007 to 2012. Hospitals were first divided into risk-adjusted mortality tertiles. We then determined rates of severe complications and FTR within each tertile. For EVAR, risk-adjusted hospital mortality rates varied significantly between the lowest and highest tertiles (0.07% vs 6.14%; P < .01). However, while major complication rates were almost identical (9.0 vs 9.8; P = NS), FTR rates were about 35 times greater in high-mortality hospitals (4.0% vs 33.3%). Similar associations with mortality, severe complications, and FTR were seen for OAR as well. The most common complications that led to FTR events were postoperative transfusion (OAR 29.8% vs EVAR 5.8%) and prolonged ventilation (OAR 18.2% vs EVAR 1.0%). The average number of severe complications per FTR event was 2.85 and 2.66 for OAR and EVAR, respectively. FTR appears to drive a large proportion of the variation in mortality associated with abdominal aortic aneurysm repair. The exact mechanisms underlying this variation remain unknown. Nonetheless, FTR is influenced by the structural characteristics and safety culture related to the timely recognition and management of severe complications. Hospitals that are unable to effectively handle severe complications following EVAR or OAR require close scrutiny.

Waits SA ，Sheetz KH ，Campbell DA ，Ghaferi AA ，Englesbe MJ ，Eliason JL ，Henke PK ... -  《-》

Failure to rescue trends in elective abdominal aortic aneurysm repair between 1995 and 2011.

Factors affecting mortality after abdominal aortic aneurysm (AAA) repair have been extensively studied, but little is known about the effects of the shift to endovascular aneurysm repair (EVAR) vs open repair on failure to rescue (FTR). This study examines the impact of treatment modalities on FTR for elective AAA surgery during the years 1995 to 2011. Data for 491,779 patients undergoing elective AAA surgery were collected from Medicare files. Patient demographics, comorbidities, hospital volume, and repair type were collected. Primary outcome was FTR: the percentage of deaths in patients who had a complication within 30 days of surgery. Data were analyzed by univariate and multivariate analysis. Patients undergoing AAA surgery have become progressively more complex, with 84.96%, 89.33%, 93.76%, and 95.72% presenting with one or more comorbidities in 1995, 2000, 2005, and 2011, respectively. Despite this, overall FTR after AAA surgery was stable from 1995 to 2000 (P = .38) and decreased from 2.68% to 1.58% between 2000 and 2011 (P < .001). In addition, FTR in EVAR decreased from 1.70% to 0.58% from 2000 to 2006 (P = .03) and then stabilized at 0.88% ± 0.9% after 2007 (P = .45). Unlike for EVAR, FTR for open repair remained stable at 3.06% ± 0.17% to 2.74% ± 0.16% from 1995 to 2000 (P = .38) but increased to 4.51% ± 0.21% in 2011 (P < .001). Mortality was highest after transfusion (20.86%), prolonged ventilation (17.37%), and respiratory complications (29.78%) for all AAA surgeries. Of note, high-volume hospitals had lower FTR rates than low-volume hospitals for both open (2.73% vs 5.66%; P < .001) and endovascular (0.7% vs 1.69%; P < .001) repair. Multivariate analysis showed that high annual volume hospital status (odds ratio, 0.6; confidence interval, 0.58-0.63) and endovascular repair (odds ratio, 0.3; confidence interval, 0.28-0.31) were associated with decreased FTR. The success in AAA surgery of rescuing patients from 30-day mortality after a complication is associated with increased volume of EVAR. This increased success can also be attributed to the improved FTR outcomes and complication rates when surgeries are performed at high-volume hospital centers.

Ilonzo N ，Egorova NN ，McKinsey JF ，Nowygrod R ... -  《-》