Hospital Volume-outcome Relationship Research Articles

The influence of hospital volume and physician volume on early mortality in acute promyelocytic leukemia patients

Acute promyelocytic leukemia (APL) is a highly curable hematologic malignancy in the era of all-trans retinoic acid (ATRA) combination treatment. However, only a modest change in early mortality rate has been observed despite the wide availability of ATRA. In addition to the clinical characteristics of APL patients, studies on the hospital volume-outcome relationship and the physician volume-outcome relationship remained limited. We aim to evaluate the association between hospital and physician volume and the early mortality rate among APL patients. The patients were collected from Taiwan’s National Health Insurance Research Database (NHIRD). Early mortality is defined as death within 30 days of diagnosis. Patients were categorized into four groups according to individual cumulative hospital and physician volume. The risk of all-cause mortality in APL patients with different cumulative volume groups was compared using a Cox proportional hazard model. The probability of overall survival was estimated using the Kaplan–Meier method. All 741 patients were divided into four quartile volume groups. In the multivariate analysis, only physician volume was significantly associated with early mortality rate. The physician volume of the highest quartile was a protective factor for early mortality compared with the physician volume of the lowest quartile (HR 0.10, 95% CI 0.02–0.65). Hospital characteristics were not associated with early mortality. In the sensitivity analyses, the results remained consistent using two other different definitions of early mortality. Higher physician volume was independently associated with lower early mortality, while hospital volume was not. Enhancing the clinical expertise of low-volume physicians may ensure better outcomes.

Outcomes After Pectus Excavatum Repair: Center Volume Matters

PurposePectus excavatum (Pectus) repair may be offered for those with significant cardiopulmonary compromise or severe cosmetic defects. The influence of hospital center volume on postoperative outcomes in children is unknown. This study aimed to investigate the outcomes of children undergoing Pectus repair, stratified by hospital surgical volume. MethodsThe Nationwide Readmission Database was queried (2016–2020) for patients with Pectus (Q67.6). Patients were stratified into those who received repair at high-volume centers (HVCs; ≥20 repairs annually) versus low-volume centers (LVCs; <20 repairs annually). Demographics and outcomes were analyzed using standard statistical tests. ResultsA total of 9414 patients with Pectus underwent repair during the study period, with 69% treated at HVCs and 31% at LVCs. Patients at LVCs experienced higher rates of complications during index admission, including pneumothorax (23% vs. 15%), chest tube placement (5% vs. 2%), and overall perioperative complications (28% vs. 24%) compared to those treated at HVCs, all p < 0.001.Patients treated at LVCs had higher readmission rates within 30 days (3.8% vs. 2.8% HVCs) and overall readmission (6.8% vs. 4.7% HVCs), both p < 0.010. Among readmitted patients (n = 547), the most frequent complications during readmission for those initially treated at LVCs included pneumothorax/hemothorax (21% vs. 8%), bar dislodgment (21% vs. 12%), and electrolyte disorders (15% vs. 9%) compared to those treated at HVCs. ConclusionPediatric Pectus repair performed at high-volume centers was associated with fewer index complications and readmissions compared to lower-volume centers. Patients and surgeons should consider this hospital volume-outcome relationship. Type of StudyRetrospective Comparative. Level of EvidenceIII.

Association of hospital volume with postoperative outcomes in Crohn's disease.

Most patients diagnosed with Crohn's disease (CD) require surgery during their lifetime. While the literature has shown that certain cancer patients have superior postoperative outcomes at high-volume hospitals, there remains a paucity of data on the hospital volume-outcome relationship in CD. Given the complexities in both medical and surgical management, this study aims to determine whether patients with CD have superior postoperative outcomes at high-volume hospitals. A retrospective analysis of patients undergoing abdominal surgery for CD in New York hospitals between 2012 and 2018 was performed using data from the Statewide Planning and Research Cooperation System. Outcomes included postoperative mortality, 30-day readmission and postoperative complications. Using a penalized B-spline plot, high-volume centres were defined as those performing more than 160 abdominal surgeries for CD each year. A total of 13,221 surgeries were performed across 176 hospital centres in New York State. Of these, 73.9% of procedures occurred at low-volume centres. High-volume hospitals had lower in-hospital mortality (0.5% vs. 1.5%; p< 0.001) and 30-day readmission rates (8.3% vs. 10.4%; p< 0.001) than low-volume centres. Major postoperative complications and reoperation rates did not differ by hospital volume. On multivariate analysis, patients at high-volume hospitals had lower odds of in-hospital mortality (OR 0.54, 95% CI 0.38-0.75) and 30-day readmission (OR 0.79, 95%CI 0.64-0.98). Hospital volume remained an independent predictor of 30-day readmission for emergent admissions (OR 0.72, 95% CI 0.61-0.85) and in-hospital mortality for nonemergent admissions (OR 0.39, 95% CI 0.19-0.82). Patients undergoing abdominal surgery for CD have lower odds of postoperative mortality and 30-day readmission when the operation occurs at a high-volume hospital. These findings suggest that surgical patients with CD may benefit from care at specialized centres.

What underlies the observed hospital volume-outcome relationship?

BackgroundStudies of the hospital volume-outcome relationship have highlighted that a greater volume activity improves patient outcomes. While this finding has been known for years, most studies to date have failed to delve into what underlies this relationship.ObjectiveThis study aimed to shed light on the basis of the hospital volume effect on patient outcomes by comparing treatment modalities for epithelial ovarian carcinoma patients.DataAn exhaustive dataset of 355 patients in first-line treatment for Epithelial Ovarian Carcinoma (EOC) in 2012 in three regions of France was used. These regions account for 15% of the metropolitan French population.MethodsIn the presence of endogeneity induced by a reverse causality between hospital volume and patient outcomes, we used an instrumental variable approach. Hospital volume of activity was instrumented by the distance from patients’ homes to their hospital, the population density, and the median net income of patient municipalities.ResultsBased on our parameter estimates, we found that the rate of complete tumor resection would increase by 15.5 percentage points with centralized care, and by 8.3 percentage points if treatment decisions were coordinated by high-volume centers compared to decentralized care.ConclusionAs volume alone is an imperfect correlate of quality, policy-makers need to know what volume is a proxy for in order to devise volume-based policies.

Hospital Volume-Outcome Relationship in Severe Traumatic Brain Injury: A Nationwide Observational Study in Japan

The hospital volume-outcome relationship in patients with severe traumatic brain injury (TBI) remains unclear. This study investigated the association between the volume of patients with severe TBI and in-hospital mortality. This observational study identified patients with severe TBI (Glasgow Coma Scale score <9 and Abbreviated Injury Scale head score ≥3) from the Japan Trauma Databank (2010-2018). Hospitals were grouped on the basis of annual patient volume as follows: low-volume (4-19 patients/year); middle-volume (20-35 patients/year); and high-volume (36-51 patients/year) groups. The association between hospital volume categories and in-hospital mortality was examined using a multivariate mixed-effect logistic regression analysis. A subgroup analysis was performed based on the presence of severe extracranial injuries. A total of 11,344 patients from 64 hospitals were included. The median age of the patients was 57 years (interquartile range, 40-77), and 7933 (70.0%) patients were men. A total of 4879 (43.1%) patients died in the hospital. The medium-volume (adjusted odds ratio [OR], 0.76; 95% confidence interval [CI], 0.62-0.93) and high-volume (adjusted OR, 0.69; 95% CI, 0.52-0.94) groups were significantly associated with lower in-hospital mortality. The subgroup analysis revealed that the medium-volume (adjusted OR, 0.70; 95% CI, 0.54-0.92) and high-volume (adjusted OR, 0.64; 95% CI, 0.42-0.96) groups were significantly associated with lower in-hospital mortality for isolated TBI patients. Higher hospital volumes were significantly associated with lower in-hospital mortality after severe TBI. Regionalization and referral to higher-volume hospitals are beneficial for severe TBI patients.

Abstract 14040: Hospital Volume-Outcome Relationship After Primary Percutaneous Coronary Intervention: A Contemporary Nationwide Analysis

Introduction: There is paucity of data on the relationship between hospital procedural volume and outcomes of primary percutaneous coronary intervention (PCI) procedures in the past decade. Methods: We queried the National Inpatient Sample database (2010-2016) for hospitalizations undergoing primary PCI for STEMI. Hospitals were divided into 3 groups: low-volume (&lt;36 primary PCI/ year), moderate-volume (36-72 primary PCI/year) and high-volume (&gt;72 primary PCI/ year). The main outcome was in-hospital mortality. Results: The analysis included 694,505 hospitalizations for primary PCI. There were 329,878 (47.5%) primary PCI procedures performed at low-volume hospitals, 224,317 (32.3%) at moderate-volume, and 140,223 (20.2%) at high-volume hospitals. Compared with high-volume hospitals, low-volume hospitals were associated with higher in-hospital mortality in the unadjusted model (5.3% vs. 4.8%, odds ratio [OR] 1.10; 95% confidence interval-CI 1.02-1.18, p=0.01) and on multivariable analysis (adjusted-OR 1.15; 95%CI 1.04-1.27, p=0.01). There was no difference between moderate-volume and high-volume hospital in unadjusted analysis (5.1% vs. 4.8%, OR 1.07; 95%CI 0.99-1.15, p=0.11) and on multivariable analysis (adjusted-OR 1.08; 95%CI 0.97-1.20, p=0.17). Conclusions: This nationwide analysis showed that low-volume hospitals are associated with higher in-hospital mortality after primary PCI compared with high-volume hospitals even in recent years. The current threshold set by national guidelines for primary PCI hospitals remains valid in contemporary practice.

Assessing the hospital volume-outcome relationship in surgery: a scoping review

IntroductionMany recent studies have investigated the hospital volume-outcome relationship in surgery. In some cases, the results have prompted the centralization of surgical activity. However, the methodologies and interpretations differ markedly from one study to another. The objective of the present scoping review was to describe the various features used to assess the volume-outcome relationship: the analyzed datasets, study population, outcome, covariates, confounders, volume modalities, and statistical methods.Methods and analysisThe review was conducted according to a study protocol published in BMJ Open in 2020. Two authors (both of whom had helped to design the study protocol) screened publications independently according to the title, the abstract and then the full text. To ensure exhaustivity, all the papers included by each reviewer went through to the next step.InterpretationThe 403 included studies covered 90 types of surgery, 61 types of outcome, and 72 covariates or potential confounders. 191 (47.5%) studies focussed on oncological surgery and 37.8% focussed visceral or digestive tract surgery. Overall, 86.6% of the studies found a statistically significant volume-outcome relationship, although the findings differed from one type of surgery to another. Furthermore, the types of outcome and the covariates were highly diverse. The majority of studies were performed in Western countries, and oncological and visceral surgical procedures were over-represented; this might limit the generalizability and comparability of the studies’ results.

Perspective of potential patients on the hospital volume-outcome relationship and the minimum volume threshold for total knee arthroplasty: a qualitative focus group and interview study

BackgroundTotal knee arthroplasty (TKA) is performed to treat end-stage knee osteoarthritis. In Germany, a minimum volume threshold of 50 TKAs/hospital/year was implemented to ensure outcome quality. This study, embedded within a systematic review, aimed to investigate the perspectives of potential TKA patients on the hospital volume-outcome relationship for TKA (higher volumes associated with better outcomes).MethodsA convenience sample of adults with knee problems and heterogeneous demographic characteristics participated in the study. Qualitative data were collected during a focus group prior to the systematic review (n = 5) and during telephone interviews, in which preliminary results of the systematic review were discussed (n = 16). The data were synthesised using content analysis.ResultsAll participants (n = 21) believed that a hospital volume-outcome relationship exists for TKA while recognising that patient behaviour or the surgeon could also influence outcomes. All participants would be willing to travel longer for better outcomes. Most interviewees would choose a hospital for TKA depending on reputation, recommendations, and service quality. However, some would also choose a hospital based on the results of the systematic review that showed slightly lower mortality/revision rates at higher-volume hospitals. Half of the interviewees supported raising the minimum volume threshold even if this were to increase travel time to receive TKA.ConclusionsPotential patients believe that a hospital volume-outcome relationship exists for TKA. Hospital preference is based mainly on subjective factors, although some potential patients would consider scientific evidence when making their choice. Policy makers and physicians should consider the patient perspectives when deciding on minimum volume thresholds or recommending hospitals for TKA, respectively.

Hospital volume following major surgery for gastric cancer determines in-hospital mortality rate and failure to rescue: a nation-wide study based on German billing data (2009-2017).

For many cancer resections, a hospital volume-outcome relationship exists. The data regarding gastric cancer resection-especially in the western hemisphere-are ambiguous. This study analyzes the impact of gastric cancer surgery caseload per hospital on postoperative mortality and failure to rescue in Germany. All patients diagnosed with gastric cancer from 2009 to 2017 who underwent gastric resection were identified from nation-wide administrative data. Hospitals were grouped into five equal caseload quintiles (I-V in ascending caseload order). Postoperative deaths and failure to rescue were determined. Forty-six thousand one hundred eighty-seven patients were identified. There was a significant shift from partial resections in low-volume hospitals to more extended resections in high-volume centers. The overall in-house mortality rate was 6.2%. The crude in-hospital mortality rate ranged from 7.9% in quintile I to 4.4% in quintile V, with a significant trend between volume categories (p < 0.001). In the multivariable logistic regression analysis, quintile V hospitals (average of 29 interventions/year) had a risk-adjusted odds ratio of 0.50 (95% CI 0.39-0.65), compared to the baseline in-house mortality rate in quintile I (on average 1.5 interventions/year) (p < 0.001). In an analysis only evaluating hospitals with more than 30 resections per year mortality dropped below 4%. The overall postoperative complication rate was comparable between different volume quintiles, but failure to rescue (FtR) decreased significantly with increasing caseload. Patients who had gastric cancer surgery in hospitals with higher volume had better outcomes and a reduced failure to rescue rates for severe complications.

Hospital volume-outcome relationship in vulvar cancer treatment: a Japanese Gynecologic Oncology Group study.

Hospital volume-outcome relationship in vulvar cancer treatment: a Japanese Gynecologic Oncology Group study.

Assessing the hospital volume-outcome relationship in surgery: a scoping review protocol

IntroductionEven if a positive volume-outcome correlation in surgery is mostly admitted in many surgical fields, the various ways to assess this relationship make it difficult for researchers and policymakers to...

The Impact of Hospital Volume on Short-term and Long-term Outcomes for Patients Undergoing Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma

To examine the effect of hospital volume on short and long-term outcomes for radical nephroureterectomy (RNUx). Upper tract urothelial carcinoma is a rare malignancy that few surgeons have experience with. The hospital volume-outcome relationship has been well established for other cancers but not RNUx. The National Cancer Database was queried for all cases of upper tract urothelial carcinoma that underwent RNUx from 2004 to 2016. Average annual hospital volume for radical nephroureterectomy was stratified into tertiles. The upper tertile, defined as 6 or more RNUx per year, was considered high volume while low volume was less than 6 RNUx per year. Kaplan-Meier and Cox proportional hazards regression were used to identify independent predictors of overall survival, and logistic regression was used to identify predictors of perioperative outcomes. We identified 37,479 RNUx performed across 1290 hospitals. There were no differences in baseline health or cancer staging between patients who presented at low- versus high-volume centers. Both peri-operative survival (30- and 90-day mortality) and long-term overall survival were improved in patients treated at high-volume centers. On multivariable survival analysis, treatment at a high-volume center was associated with improved hazards of survival. This relationship for long-term survival remained consistent on landmark analysis where patients who died within 90 days of surgery were removed. Treatment at a high-volume hospital was associated not only with improved short-term perioperative outcomes but also with improved overall long-term survival. The mechanism behind this is likely multifactorial with surgeon volume, and ancillary support services all playing critical roles.

Fenestrated repair improves perioperative outcomes but lacks a hospital volume association for complex abdominal aortic aneurysms

BackgroundComplex abdominal aortic aneurysms (AAAs) have traditionally been treated with an open surgical repair (OSR). During the past decade, fenestrated endovascular aneurysm repair (FEVAR) has emerged as a viable option. Hospital procedural volume to outcome relationship for OSR of complex AAAs has been well established, but the impact of procedural volume on FEVAR outcomes remains undefined. This study investigated the outcomes of OSR and FEVAR for the treatment of complex AAAs and examined the hospital volume-outcome relationship for these procedures. MethodsA retrospective review of a statewide vascular surgery registry was queried for all patients between 2012 and 2018 who underwent elective repair of a juxtarenal/pararenal AAA with FEVAR or OSR. The primary outcomes were 30-day mortality, myocardial infarction, and new dialysis. Secondary end points included postoperative pneumonia, renal dysfunction (creatine concentration increase of >2 mg/dL from preoperative baseline), major bleeding, early procedural complications, length of stay, and need for reintervention. To evaluate procedural volume-outcomes relationship, hospitals were stratified into low- and high-volume aortic centers based on a FEVAR annual procedural volume. To account for baseline differences, we calculated propensity scores and employed inverse probability of treatment weighting in comparing outcomes between treatment groups. ResultsA total of 589 patients underwent FEVAR (n = 186) or OSR (n = 403) for a complex AAA. After adjustment, OSR was associated with higher rates of 30-day mortality (10.7% vs 2.9%; P < .001) and need for dialysis (11.3% vs 1.8; P < .001). Postoperative pneumonia (6.8% vs 0.3%; P < .001) and need for transfusion (39.4% vs 10.4%; P < .001) were also significantly higher in the OSR cohort. The median length of stay for OSR and FEVAR was 9 days and 3 days, respectively. For those who underwent FEVAR, endoleaks were present in 12.1% of patients at 30 days and 6.1% of patients at 1 year, with the majority being type II. With a median follow-up period of 331 days (229-378 days), 1% of FEVAR patients required a secondary procedure, and there were no FEVAR conversions to an open aortic repair. Hospitals were divided into low- and high-volume aortic centers based on their annual FEVAR volume of complex AAAs. After adjustment, hospital FEVAR procedural volume was not associated with 30-day mortality or myocardial infarction. ConclusionsFEVAR was associated with lower perioperative morbidity and mortality compared with OSR for the management of complex AAAs. Procedural FEVAR volume outcome analysis suggests limited differences in 30-day morbidity, although long-term durability warrants further research.

Hospital volume-outcome relationship in severe traumatic brain injury: stratified analysis by level of trauma center.

The nature of the volume-outcome relationship in cases with severe traumatic brain injury (TBI) remains unclear, with considerable interhospital variation in patient outcomes. The objective of this study was to understand the state of the volume-outcome relationship at different levels of trauma centers in the United States. The authors queried the National Trauma Data Bank for the years 2007-2014 for patients with severe TBI. Case volumes for each level of trauma center organized into quintiles (Q1-Q5) served as the primary predictor. Analyzed outcomes included in-hospital mortality, total hospital length of stay (LOS), and intensive care unit (ICU) stay. Multivariable regression models were performed for in-hospital mortality, overall complications, and total hospital and ICU LOSs to adjust for possible confounders. The analysis was stratified by level designation of the trauma center. Statistical significance was established at p < 0.001 to avoid a type I error due to a large sample size. A total of 122,445 patients were included. Adjusted analysis did not demonstrate a significant relationship between increasing hospital volume of severe TBI cases and in-hospital mortality, complications, and nonhome hospital discharge disposition among level I-IV trauma centers. However, among level II trauma centers, hospital LOS was longer for the highest volume quintile (adjusted mean difference [MD] for Q5: 2.83 days, 95% CI 1.40-4.26 days, p < 0.001, reference = Q1). For level III and IV trauma centers, both hospital LOS and ICU LOS were longer for the highest volume quintile (adjusted MD for Q5: LOS 4.6 days, 95% CI 2.3-7.0 days, p < 0.001; ICU LOS 3.2 days, 95% CI 1.6-4.8 days, p < 0.001). Higher volumes of severe TBI cases at a lower level of trauma center may be associated with a longer LOS. These results may assist policymakers with target interventions for resource allocation and point to the need for careful prehospital decision-making in patients with severe TBI.

Hospital volume-outcome relationship in total knee arthroplasty: protocol for a systematic review and non-linear dose-response meta-analysis

BackgroundKnee osteoarthritis is a common, chronic condition and main contributor to global disability. Total knee arthroplasty (TKA) is the most successful treatment for end-stage knee osteoarthritis. It is assumed that in the field of surgery, there is a relationship between hospital volume and health outcomes and that higher hospital volume results in better health outcomes. As a consequence, minimum volume thresholds have been implemented in Germany for various procedures, including TKA (50 procedures per year). To date, it is unclear whether minimum volume thresholds truly result in better outcomes.The objective of this study will be to quantify the relationship between hospital volume and patient-relevant outcomes in patients undergoing TKA.MethodsWe will include published or unpublished (cluster-) randomized controlled trials and prospective or retrospective cohort studies that involve patients with primary and/or revision TKA, report at least two different hospital volumes and report at least one patient-relevant outcome. To identify studies, we will systematically search (from inception onwards) PubMed/MEDLINE, Embase, CENTRAL, and CINAHL, as well as trial registers, conference proceedings, and reference lists. We will also contact experts in the field. Study selection and data extraction will be performed by two reviewers independently. The primary outcome will be rate of early revision. Secondary outcomes will include rate of revision > 1 year, mortality, length of stay, readmission rate, surgical complications, adverse events and health-related quality of life. We will assess the risk of bias of the included studies using ROBINS-I or the Cochrane risk of bias tool. Both a linear and a non-linear dose-response meta-analyses will be performed. We will use the GRADE approach to evaluate our confidence in the cumulative evidence. We will incorporate patients’ needs, goals and preferences into our recommendations by consulting three focus groups, each consisting of eight participants.DiscussionThe findings of our systematic review will probably be limited by the design of the included studies. We do not expect to identify any (cluster-) randomized controlled trials that meet our inclusion criteria. Therefore, the best available evidence included in our systematic review will most likely consist of cohort studies only. We anticipate that the results of this study will inform future health policy decisions in Germany regarding the minimum volume threshold for TKA.Systematic review registration: PROSPERO CRD42019131209

Outcomes of Primary versus Multiple-Staged Repair in Hirschsprung's Disease in England.

The study aimed to compare 1-year outcomes for primary versus multiple-staged (three operations with colostomy) repairs in Hirschsprung's disease (HD). Retrospective analysis of a large national administrative database (Hospital Episode Statistics) including all the neonates born with HD in England between 2003 and 2015. Main outcomes were: 1-year mortality, postoperative readmissions, and reoperations. cumulative length of hospital stay (cLOS) and hospital volume-outcome relationship. A total of 1,333 neonates with HD were treated in 21 specialist pediatric surgical centers; 874 (65.5%) patients had a primary repair for HD. One-year mortality was 2.8%. The overall readmission rate was 70.2%, with a significant difference between primary and multiple-staged repair (79.9 vs. 90.1%, p < 0.01). There was no difference in reoperation. Primary pull-through was associated with a significantly lower probability of postoperative readmission (odds ratio [OR] = 0.08, 95% confidence interval [CI] = 0.06-0.11, p < 0.001) and cLOS (OR = 0.38, 95% CI = 0.28-0.52, p < 0.001) compared with multiple-staged repair. There were no significant difference in outcomes between patients treated in low-volume (<37 cases/year) and high-volume (> 55 cases/year) specialist centers. Whenever clinically indicated, primary repair should be used in HD as this is associated with fewer readmissions and shorter time spent in the hospital.

Fenestrated Endograft Repair Is Associated With Improved Perioperative Outcomes but Absence of Hospital Volume Relationship in Comparison to Open Surgical Repair of Complex Abdominal Aortic Aneurysms

Complex abdominal aortic aneurysms (cAAAs) have traditionally been treated with an open surgical repair (OSR). During the past decade, fenestrated endovascular aneurysm repair (FEVAR) has emerged as a viable option. During this time, the hospital procedural volume to outcome relationship for OSR of cAAAs has been well established, but the impact of procedural volume on FEVAR outcomes remains undefined. This study investigated the outcomes of OSR and FEVAR for the treatment of cAAAs and examined the hospital volume-outcome relationship for these procedures. A retrospective review of a statewide vascular surgery registry was queried for all patients between 2012 and 2018 who underwent elective repair of a juxtarenal AAA with FEVAR or OSR. The primary outcomes were 30-day mortality, myocardial infarction, and new dialysis. Secondary end points included postoperative pneumonia, renal dysfunction (creatine concentration increase of >2 mg/dL from preoperative baseline), major bleeding, early procedural complications, length of stay, and need for reintervention. To evaluate procedural volume-outcome relationships, hospitals were stratified into low- and high-volume aortic centers on the basis of an annual procedural volume of four juxtarenal AAA repairs per year. To account for baseline differences, we calculated propensity scores and employed probability weighting. A total of 590 patients underwent FEVAR (n = 187) or OSR (n = 403) for cAAAs. After adjustment, OSR was associated with higher rates of 30-day mortality (10.6% vs 3.2%; P = .001), myocardial infarction (3.9% vs 0.81%; P = .29), and need for dialysis (13.5% vs 3.7%; P = .001). Postoperative pneumonia (6.8% vs 0.44%; P = .001) and need for transfusion (35.3% vs 9.6%; P = .001) were also significantly higher in the OSR cohort. The median length of stay for OSR and FEVAR was 9 days and 3 days, respectively. For those who underwent FEVAR, endoleaks were present in 11.6% of patients at 30 days and 5.4% of patients at 1 year, with the majority being type II. One percent of FEVAR patients required a secondary procedure with a median follow-up period of 331 days (229-378 days), and there were no FEVAR conversions to an open aortic repair during this period. Hospitals were divided into low- and high-volume aortic centers on the basis of their annual FEVAR cAAA volume. After adjustment, hospital FEVAR procedural volume was not associated with 30-day mortality or myocardial infarction. FEVAR was associated with lower perioperative morbidity and mortality compared with OSR for the management of complex AAAs. Procedural FEVAR volume-outcome analysis suggests no difference in 30-day morbidity or mortality between low- and high-volume centers, although long-term durability warrants further research.

Relationship between operator and hospital volumes and short-term mortality for percutaneous coronary intervention in New York

BackgroundRecent studies have reported mixed findings regarding the inverse provider volume-outcome relationship for percutaneous coronary interventions (PCIs). MethodsWe included patients who underwent PCIs in New York during December 2012–November 2015. Using risk-adjusted in-hospital/30-day mortality rate and appropriateness of PCI, we tested for a continuous relationship and a variety of annual PCI volume cut points at hospital and operator levels in investigating volume-outcome relationships. ResultsThere were 144,196 patients undergoing PCI procedures from 63 non-federal hospitals. There was a significant inverse association between risk-adjusted mortality and both annual hospital PCI volume and annual operator PCI volume. However, we did not find that there was an inverse hospital volume-outcome relationship for the 2013 ACCF/AHA/SCAI's hospital PCI volume cutoff value of 200 per year (AOR, 1.15, 95% CI, 0.88–1.51, P = 0.32) or a significant inverse operator volume-outcome relationship using the operator PCI volume cutoff value of 50 per year (AOR, 0.89, 95% CI, 0.70–1.12, P = 0.32) or for any other practical volume cutoffs. There was also no significant volume-outcome relationship for STEMI patients. Higher volume hospitals (>400) and operators (>200) tended to perform a higher percentage of inappropriate PCI procedures than their lower volume counterparts. ConclusionThere were no significant PCI volume-mortality relationships for either hospitals or operators for any practical volume cuts. Higher volume hospitals and operators were associated with higher percentages of inappropriate PCIs.

PCN223 - WHAT UNDERLIES THE OBSERVED HOSPITAL VOLUME-OUTCOME RELATIONSHIP?

Studies of the hospital volume-outcome relationship have highlighted that a greater volume activity improves patient outcomes. While this finding has been known for years in health services research, most studies to date have failed to delve into what underlies this relationship. This study aimed to shed light on the basis of the hospital volume effect by comparing treatment modalities for epithelial ovarian carcinoma (EOC) patients. We used three clinical databases that contained exhaustive datasets of patients in first-line treatment for EOC in 2012 in three regions of France (n=355). Hospital volume activity was instrumented by the distance from patients’ homes to their hospital, and the population density. We used complete tumor resection as a quality indicator. We found that higher volume hospitals appear to more often make the right decisions in regard to how to treat patients, which contributes to the positive impact of hospital volume activities on patient outcomes. Based on our parameter estimates, we found that the rate of complete tumor resection would increase by 10% with centralized care, and by 6% if treatment decisions were coordinated by high volume centers compared to the ongoing organization of care. In both scenarios, the use of neoadjuvant chemotherapy would increase by 10%. As volume alone is an imperfect correlate of quality, policy makers need to know what volume is a proxy for in order to devise volume-based policies. Centralized care at high volume hospitals was the scenario that led to the highest average patient outcome. However, several barriers, such as the increase in patient travel distances, have prevented such a reform of the organization of care from being applied. An intermediate solution between centralized and decentralized care could be to make lower volume hospitals benefit from the expertise of higher volume hospitals when making treatment decisions.

What Underlies the Observed Hospital Volume-Outcome Relationship?

Studies of the hospital volume-outcome relationship have highlighted that a greater volume activity improves patient outcomes. While this finding has been known for years in health services research, most studies to date have failed to delve into what underlies this relationship. This study aimed to shed light on the basis of the hospital volume effect by comparing treatment modalities for epithelial ovarian carcinoma patients. Hospital volume activity was instrumented by the distance from patients’ homes to their hospital, the population density, and the median net income of patient municipalities. We found that higher volume hospitals appear to more often make the right decisions in regard to how to treat patients, which contributes to the positive impact of hospital volume activities on patient outcomes. Based on our parameter estimates, we found that the rate of complete tumor resection would increase by 10% with centralized care, and by 6% if treatment decisions were coordinated by high volume centers compared to the ongoing organization of care. In both scenarios, the use of neoadjuvant chemotherapy would increase by 10%. As volume alone is an imperfect correlate of quality, policy makers need to know what volume is a proxy for in order to devise volume-based policies.