The relative effect of hospital and surgeon volume on failure to rescue among patients undergoing liver resection for cancer.

Although previous reports have focused on factors at the hospital level to explain variations in postoperative outcomes, less is known regarding the effect of provider-specific factors on postoperative outcomes such as failure-to-rescue (FTR) and postoperative mortality. The current study aimed to quantify the relative contributions of surgeon and hospital volume on the volume-outcomes relationship among a cohort of patients undergoing liver resection. Patients undergoing liver surgery for cancer were identified using the Nationwide Inpatient Sample from 2001 and 2009. Multivariable logistic regression analysis was performed to identify factors associated with mortality and FTR. Point estimates were used to calculate the relative effects of hospital and surgeon volume on mortality and FTR. A total of 5,075 patients underwent liver surgery and met inclusion criteria. Median patient age was 62 years (interquartile range, 52-70) and 55.2% of patients were male. Mortality was lowest among patients treated at high-volume hospitals and among patients treated by high-volume surgeons (both P < .001). Similar patterns in FTR were noted relative to hospital and surgeon volume (hospital volume: low vs intermediate vs high; 10.3 vs 9.0 vs 5.2%; surgeon volume: low vs intermediate vs high, 11.1 vs 9.1 vs 4.1%; both P < .05). On multivariable analysis, compared with high-volume surgeons, lower volume surgeons demonstrated greater odds for mortality (intermediate: odds ratio [OR], 2.27 [95% CI, 1.27-4.06; P = .006]; low, OR, 2.83 [95% CI, 1.52-5.27; P = .001]), and FTR (intermediate: OR, 2.86 [95% CI, 1.53-5.34, P = .001]; low, OR, 3.40 [95% CI, 1.75-6.63; P < .001]). While hospital volume accounted for 0.5% of the surgeon volume effect on increased FTR for low-volume surgeons, surgeon volume accounted for nearly all of the hospital volume effect on increased FTR in low-volume hospitals. The risk of complications, mortality, and FTR were less among both high-volume hospitals and high-volume surgeons, but the beneficial effect of volume on outcomes was attributable largely to surgeon volume.

Buettner S ，Gani F ，Amini N ，Spolverato G ，Kim Y ，Kilic A ，Wagner D ，Pawlik TM ... -  《-》

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 ... -  《-》

Operative outcomes in mitral valve surgery: combined effect of surgeon and hospital volume in a population-based analysis.

We evaluated the combined effect of hospital and surgeon volume on operative outcomes of mitral valve surgery in the United States. The Nationwide Inpatient Sample was used to identify adult patients undergoing isolated mitral valve surgery for mitral regurgitation from 2003 to 2008. Hospitals and surgeons were separately stratified into equal-size tertiles according to annual overall mitral valve operative volumes. Multivariate logistic regression analysis was conducted, adjusting for multiple patient, hospital, and operative data, to determine the separate and combined effects of hospital and surgeon volume on operative outcomes. A total of 50,152 eligible patients were identified during the study period. Although both hospital and surgeon volume correlated significantly with operative mortality in separate risk-adjusted analyses, only lower surgeon volume persisted as a significant risk factor in the combined risk-adjusted analysis. Moreover, although hospital volume only accounted for 10.7% of the surgeon volume effect on increased mortality for low-volume surgeons, surgeon volume accounted for 74.5% of the hospital volume effect on increased mortality in low-volume hospitals. Surgeon, but not hospital, volume correlated with inpatient costs. Also, significant trends were seen with repair rates, with increasing surgeon volume demonstrating a relatively stronger correlation with the odds of repair (P < .001) than hospital volume (P = .01). The effect of hospital volume on operative outcomes of mitral valve surgery was largely driven by the individual surgeon volumes within that hospital. Conversely, surgeon volume affected these outcomes independently of hospital volume. Identifying the processes by which higher volume surgeons attain better outcomes in mitral valve surgery would therefore be prudent.

Kilic A ，Shah AS ，Conte JV ，Baumgartner WA ，Yuh DD ... -  《-》

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 ... -  《-》

Failure to rescue as a source of variation in hospital mortality after hepatic surgery.

The mechanisms that underlie the association between high surgical volume and improved outcomes remain uncertain. This study examined the impact of complications and failure to rescue patients from these complications on mortality following hepatic resection. The Nationwide Inpatient Sample was used to identify patients who had liver surgery between 2000 and 2010. Hospital volume was stratified into tertiles (low, intermediate and high). Rates of major complications, failure to rescue and mortality following hepatic surgery were compared. Some 9874 patients were identified. The major complication rate was 19.6 per cent in low-volume, 19.3 per cent in intermediate-volume and 16.6 per cent in high-volume hospitals (P < 0.001). Most common major complications included respiratory insufficiency or failure (8.8 per cent), acute renal failure (4.2 per cent) and gastrointestinal bleeding (3.9 per cent), with each of these complications being less common in high-volume hospitals (P < 0.050). The incidence of major morbidity following hepatectomy remained the same over the past decade, but failure to rescue patients from these complications decreased (P = 0.011). The overall inpatient mortality rate following liver surgery was 3.2 per cent (3.8, 3.6 and 2.3 per cent for low-, intermediate- and high-volume hospitals respectively; P < 0.001). The rate of failure to rescue (death after a complication) was higher at low- and intermediate-volume hospitals (16.8 and 16.1 per cent respectively) compared with high-volume hospitals (11.8 per cent) (P = 0.032). After accounting for patient and hospital characteristics, patients treated at low-volume hospitals who had a complication were 40 per cent more likely to die than patients with a complication in a high-volume hospital (odds ratio 1.40, 95 per cent confidence interval 1.02 to 1.93). The risk of death following hepatic surgery is lower at high-volume hospitals. The reduction in mortality appears to be the result of both lower complication rates and a better ability in high-volume hospitals to rescue patients with major complications.

Spolverato G ，Ejaz A ，Hyder O ，Kim Y ，Pawlik TM ... -  《-》