Volume-outcome Relationship Research Articles

Minimum case volumes from the perspective of university providers

The association between patient volume and treatment quality has been sufficiently proven for certain surgical interventions (e.g., resections of the esophagus and pancreas). International experience shows that centralization of patient care in these fields leads to an improvement in outcome quality. If properly enforced, minimum caseload requirements can induce centralization effects in the hospital market. Overcapacities in the German hospital market and high nationwide in-hospital mortality rates (e.g., nationwide postoperative hospital mortality after esophageal and pancreatic resections) justify the current changes in the minimum caseload requirement regulation. Nevertheless, still open questions on volume-outcome relationships (e.g., additive volume effects of associated organ systems) have yet to be answered by scientific studies. In addition, the special role of university medical centers in the German healthcare system needs to be considered in the minimum caseload requirement regulation in order not to jeopardize the importance of university clinics in science, education and patient care through self-regulatory processes in the hospital market induced by minimum caseload requirements.

Surgical volume-patient outcome relationships for parathyroidectomy in the England: analysis of an administrative dataset for the Getting It Right First Time programme

Abstract Introduction Previous studies suggest a relationship between surgical volume and patient outcomes for parathyroid surgery. However, most studies are small and from outside the UK. The aim of this study was to use Hospital Episodes Statistics to investigate volume-outcome relationships for parathyroid surgery in England. Methods We examined a five-year period (April 2014-March 2019 inclusive) for elective, adult admissions for surgery for primary hyperparathyroidism without a diagnosis of multiple endocrine neoplasia, parathyroid cancer or renal disease. Volume was the number of procedures conducted in the same financial year as the index procedure. The primary outcome measure was emergency readmission at 30 days or length of stay greater than 2 days which were taken to represent poorer outcomes. Results We included 17,498 parathyroidectomies. Across the period the number of surgeons conducting parathyroid surgery changed little (280 in 2014/15 and 2018/19), although the number of procedures conducted rose from 3,331 to 3,848 per annum. From the lowest surgeon volume category (1–10 per annum) to the highest (≥ 60 per annum) the proportion of patients readmitted at 30 days or with an extended length of stay decreased 11.7% to 7.0%, diagnosis of hypoparathyroidism within one year from 16.3% to 10.9%, repeat parathyroid procedures within one year from 2.5% to 1.0% and mortality rate at one year from 1.0% to 0.5%. These differences persisted after adjustment for demographic and procedural covariates. Conclusion Higher surgeon annual volume is associated with improved patient outcomes for parathyroid surgery. BAETS should consider recommending a minimum yearly workload.

31 Quality or Quantity? An Analysis of the Colorectal Cancer Resection Volume-Outcome Relationship From the 2019 National Bowel Cancer Audit Data

Abstract Aim Despite increasing evidence supporting cancer services centralisation, no consensus exists in the association between high-hospital or high-surgeon volume and mortality following colorectal cancer surgery. This study aimed to identify and characterise a volume-outcome relationship in colorectal cancer. Method National Bowel Cancer Audit (NBOCA) dataset was combined with the Association of Coloproctology of Great Britain and Ireland (ACPGBI) Clinical Outcomes Publication (COP) 2019 report. Adjusted 90-day and 2-year mortality were derived from patients included in the 2018 and 2016 datasets, respectively. The impact of centre volume, surgeon volume and ACPGBI membership rates on outcomes was assessed. Cumulative sum (CUSUM) analysis was performed to identify the centre and surgeon volume threshold. Results 144 hospitals were included, with 17,235 and 17,703 patients from the 2018 and 2016 datasets, respectively. 781 surgeons were identified, with 478 holding ACPGBI memberships. No significant difference was found between centre or surgeon volumes for adjusted 90-day and 2-year mortality. High ACPGBI membership rates were significantly associated with a reduced 90-day (p=0.006), but not 2-year mortality (p=0.198). CUSUM analysis found 36 per year as threshold centre volume (p=0.003) and 15 surgeries per year as the threshold surgeon volume (p=0.241). Conclusions The high degree of existing centralisation for cancer services in the UK limits the number of true low-volume centres compared to other countries. Surgeon volume may be a better predictor of colorectal cancer surgery outcomes than centre volume. More granular data is needed to improve the current understanding of the association between surgeon volume, ACPGBI membership and outcomes in colorectal surgery.

Real-World Outcomes for ECMO in COVID-19

Real-World Outcomes for ECMO in COVID-19

Annual hospital volume and colorectal cancer survival in a population-based nationwide cohort study in Finland

PurposeTo examine the annual hospital volume of surgery in relation to survival in colorectal cancer. Previous studies on hospital volume and survival following colorectal cancer surgery are conflicting. MethodsAll 49 032 patients who underwent resection for colorectal cancer in 1987–2016 in Finland were included, with complete follow-up until December 31, 2019. Primary outcome was 5-year mortality. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI) for quartiles of annual hospital volume for colorectal surgery, adjusted for calendar period, age, sex, comorbidity, stage, tumor location and oncological therapy. Additionally, colon and rectal cancer surgery were assessed separately. Sensitivity analysis of patients with confirmed curative intent was conducted. ResultsCompared to highest quartile (≥108 resections annually), lowest hospital volume (≤37 resections annually) was associated with slightly increased 5-year all-cause mortality (adjusted HR 1.07, 95% CI 1.02–1.12). A pre-planned subgroup-analysis suggested a slightly improved 5-year survival in high-volume institutions for rectal cancer, but not colon cancer surgery. Sensitivity analysis including only those operated with confirmed curative intent suggested no differences between hospital volume groups in colorectal, colon or rectal cancer for 5-year all-cause mortality. ConclusionHigher hospital volume is associated with slightly improved all-cause 5-year mortality in colorectal cancer surgery, but this effect may be limited to rectal cancer surgery only. Volume-outcome relationship in rectal cancer surgery should be investigated further using large datasets. These results do not support centralization of colon cancer surgery based on hospital volume only.

Volume creates value: The volume-outcome relationship in Scandinavian obesity surgery.

This study establishes the relationship between surgical volume and cost and quality outcomes, using patient-level clinical data from a national quality registry for bariatric surgery in Sweden. Data include patient characteristics with comorbidities, surgical and follow-up data for patients that underwent gastric bypass or gastric sleeve operations between 2007 and 2016 (52,703 patients in 51 hospitals). The relationships between surgical volume (annual number of bariatric procedures) and several patient-level outcomes were assessed using multilevel, mixed-effect regression models, controlling for patient characteristics and comorbidities. We found that hospitals with higher volumes had lower risk of intraoperative complications as well as complications within 30 days post-surgery (odds ratios per 100 procedures are 0.78 and 0.87, respectively, p<0.01). In addition, higher-volume hospitals had substantially shorter procedure time (17 min per 100 procedures, p<0.01) and length of stay (0.88 incidence-rate ratio per 100 procedures p<0.01). Our results support the claim that increased surgical volume significantly improves quality. Further, the results strongly suggest that increased volume leads to lower cost per surgery, by reducing cost drivers such as procedure time and length of stay.

Assessing the hospital volume-outcome relationship in total elbow arthroplasty.

Total elbow arthroplasty (TEA) is an effective intervention for multiple elbow disorders including complex fracture in elderly patients, post-traumatic arthropathy, inflammatory arthropathy, and distal humeral nonunion. Given its known therapeutic value and low utilization rate, an investigation into the thresholds for TEA institutional volume-outcome relationships is warranted. The purpose of this study was to identify TEA volume thresholds that serve as predictors of institutional outcomes including complications, readmissions, revisions, cost of care, length of stay (LOS), and non-home discharge. We hypothesized that increased institutional volume would be associated with decreased 90-day adverse outcomes and resource utilization. The Nationwide Readmission Database was queried from 2010 to 2017 to identify all cases of TEA. Hospital volume was calculated using a unique hospital identifier and divided into quartiles. Outcomes such as complications, readmissions, revisions, cost of care, LOS, and non-home discharge were then analyzed by quartile. The same outcomes were assessed via stratum-specific likelihood ratio (SSLR) analysis to define volume strata among institutions. SSLR analysis defined statistically significant hospital volume categories for each 90-day outcome. The volume category with the lowest complication rate was ≥21 TEAs per year (5.6%). The volume categories with the lowest readmission rates were 1-3 TEAs per year (4.7%) and ≥18 TEAs per year (9.2%). Revision rates were lowest in the volume categories of 1-5 TEAs per year (0.1%) and ≥18 TEAs per year (0.1%). Hospitals with ≥21 TEAs per year had the lowest cost of care and the highest rate of extended LOS (>2 days). SSLR analysis showed that non-home discharges decreased in a stepwise manner as volume increased. The lowest non-home discharge rate was associated with the volume category of ≥22 TEAs per year (20.3%). This study defines TEA volume strata for institutional outcomes. The highest TEA volume strata were associated with the lowest rates of 90-day complications, revisions, and non-home discharges and the lowest cost of care. This trend is likely attributable to the benefits of high-volume institutional experience and standardized patient-care processes.

Relationship between hospital volumes and health outcomes: epidemiological evidence supporting the revision process of the Ministry of Health Decree no. 70 of 2 April 2015.

In this perspective, this work intends to establish whether statistical correlations exist between volumes of activity and outcomes of hospital care. The scope is limited to several clinical conditions and therapeutic procedures for which specific indicators are provided by the National Healthcare Outcomes Programme (Programma Nazionale Esiti - PNE). For each condition or procedure, the analysis shows the volume-outcome relationship by hospital centre by means of the Levenberg-Marquardt algorithm (software: XLSTAT). The existence of breakpoints is assessed through the use of segmented models (software: "segmented" R-Package). The results show a statistical correlation for the following: acute myocardial infarction (breakpoint: 91 hospitalizations per year; 95% CI: 81-101; p<0.0001); repair of an unruptured abdominal aortic aneurysm (breakpoint: 69 procedures per year; 95% CI: 52-86; p=0.146); lung cancer (breakpoint: 96 procedures per year; 95% CI: 60-132; p<0.01); knee arthroplasty (breakpoint: 91 procedures per year; 95% CI: 51-131; p=0.484). Conversely, the statistical analysis did not allow to accurately highlight a breakpoint for the isolated aorto-coronary bypass, percutaneous transluminal coronary angioplasty and hip arthroplasty. These results represent a useful knowledge contribution to support the revision process of the above-mentioned Decree. As regards the procedures that may not be currently assessed through this statistical analysis method, literature data is referred to that confirm that the current regulatory thresholds are in the safe range.

Defining minimum volume thresholds to increase quality of care: a new patient-oriented approach using mixed integer programming

A positive relationship between treatment volume and outcome quality has been demonstrated in the literature and is thus evident for a variety of procedures. Consequently, policy makers have tried to translate this so-called volume–outcome relationship into minimum volume regulation (MVR) to increase the quality of care—yet with limited success. Until today, the effect of strict MVR application remains unclear as outcome quality gains cannot be estimated adequately and restrictions to application such as patient travel time and utilization of remaining hospital capacity are not considered sufficiently. Accordingly, when defining MVR, its effectiveness cannot be assessed. Thus, we developed a mixed integer programming model to define minimum volume thresholds balancing utility in terms of outcome quality gain and feasibility in terms of restricted patient travel time and utilization of hospital capacity. We applied our model to the German hospital sector and to four surgical procedures. Results showed that effective MVR needs a minimum volume threshold of 125 treatments for cholecystectomy, of 45 and 25 treatments for colon and rectum resection, respectively, of 32 treatments for radical prostatectomy and of 60 treatments for total knee arthroplasty. Depending on procedure type and incidence as well as the procedure’s complication rate, outcome quality gain ranged between 287 (radical prostatectomy) and 977 (colon resection) avoidable complications (11.7% and 11.9% of all complications). Ultimately, policy makers can use our model to leverage MVR’s intended benefit: concentrating treatment delivery to improve the quality of care.

“Post-market” validation of guideline recommendations is a critical next step in guideline evolution

In their study, Geiger et al1 report on the volume–outcome relationship between both surgeon and hospital open aortic volume and postoperative mortality using a New York statewide database. Although many studies have been reported on this topic, their decision to assess the validity of the Society for Vascular Surgery's recommendation that open aortic procedures be limited to centers that perform ≥10 open aortic surgeries each year separates their report from the others.2 Their analysis clearly shows that this volume threshold has a strong relationship with postoperative mortality, validating it as a reliable threshold for predicting which centers will achieve acceptable results when performing open aortic surgery.

Surgeon perceptions of volume threshold and essential practices for pediatric thyroidectomy✰

IntroductionThe topics of sub-specialization and regionalization of care have garnered increased attention among pediatric surgeons. Thyroid surgeries are one such sub-specialty and are commonly concentrated within practices. A national survey was conducted examining current surgeon practices and beliefs surrounding pediatric thyroid surgery. MethodsNon-resident members of the American Pediatric Surgical Association (APSA) were surveyed in October 2020. Respondents were stratified based on self-reported thyroid surgical experience. Those who performed thyroid surgery were asked about surgical technique and operative practices; those who did not were asked about referral patterns. All respondents were asked about perceptions surrounding the volume-outcome relationship for pediatric thyroid surgery. ResultsAmong 1015 APSA members, 405 (40%) responded, with 79% (317/400) practicing at academic hospitals, 58% (232/401) practicing in major metropolitan area, and 41% (161/392) with over 10 years of attending pediatric surgery experience. Most respondents (88%, n = 356) agreed that thyroid surgery volume affects outcome, though wide variation was reported in the annual case threshold for “high volume” surgery. Eighty-four respondents (21%) reported performing ≥ 1 pediatric thyroid surgery in the past year. Of these, 82% routinely use recurrent laryngeal nerve monitoring, 32% routinely send hemithyroidectomy patients home the same day, and there was little consensus surrounding postoperative hypocalcemia management. The majority of respondents endorse performing thyroid procedures with a colleague. ConclusionsPediatric thyroid surgery appears to be performed by a subset of active pediatric surgeons, most of whom endorse the use of a dual operating team. More evidence is needed to build consensus around additional perioperative practices.

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.

The Effect of Hospital Versus Surgeon Volume on Short-Term Patient Outcomes After Pancreaticoduodenectomy: a SEER-Medicare Analysis.

The volume-outcome relationship has been well-established for pancreaticoduodenectomy (PD). It remains unclear if this is primarily driven by hospital volume or individual surgeon experience. This study aimed to determine the relationship of hospital and surgeon volume on short-term outcomes of patients with pancreatic adenocarcinoma undergoing PD. Patients >65 years of age who underwent PD for pancreatic adenocarcinoma were identified from the Surveillance, Epidemiology, and End Results(SEER)-Medicare database (2008-2015). Analyses were stratified by hospital volume and then surgeon volume, creating four volume cohorts: low-low (low hospital, low surgeon), low-high (low hospital, high surgeon), high-low (high hospital, low surgeon), high-high (high hospital, high surgeon). Propensity scores were created for the odds of undergoing surgery with high-volume surgeons. Following matching, multivariable analysis was used to assess the impact of surgeon volume on outcomes within each hospital volume cohort. In total, 2450 patients were identified: 54.3% were treated at high-volume hospitals (27.0% low-volume surgeons, 73.0% high-volume surgeons) and 45.7% were treated at low-volume hospitals (76.9% low-volume surgeons, 23.1% high-volume surgeons). On matched multivariable analysis, there were no significant differences in the risk of major complications, 90-day mortality, and 30-day readmission based on surgeon volume within the low and high hospital volume cohorts. Compared with surgeon volume, hospital volume is a more significant factor in predicting short-term outcomes after PD. This suggests that a focus on resources and care pathways, in combination with volume metrics, is more likely to achieve high-quality care for patients undergoing PD across all hospitals.

Minimum volume requirements-perspective of a tertiary care hospital

The increase of minimum volumes for complex esophageal resections decided by the Federal Joint Committee (GBA) in Germany is currently the subject of intensive discussions. To shed light on the effects of minimum volume requirements from the perspective of atertiary care hospital. Strict adherence to the valid minimum volume requirements for esophageal surgery would significantly reduce the number of hospitals offering these procedures in Germany. The associated loss of revenue should not have any relevant negative economic consequences for most hospitals; however, the loss of complex esophageal surgery may result in acompetitive disadvantage for these hospitals in times of shortage of qualified medical personnel. Another point of criticism is the assumption that the treatment quality can be recognized based solely on the numbers of patients. Despite the well-known volume-outcome relationship, minimum volume requirements do not define the lower limit of quality of surgical treatment. Therefore, additional evidence of treatment quality, such as structural or process quality as well as outcome parameters should be required, e.g. through certification. An obligatory synchronous certification could contribute to increasing the acceptance of minimum volume requirements in Germany.

Abstract PO-077: Access to care as a contributing factor to underlying disparities in Hispanic women with ovarian cancer in the United States

Abstract In the United States, ovarian cancer accounts for only 3% of all cancers in U.S. women. Ovarian cancer trends in the United States report the highest incidence in non-Hispanic white women with Hispanic women having the second highest incidence. Ovarian cancer disparities are present within the Hispanic population because Hispanic women are more likely to be diagnosed with ovarian cancer, not only at an earlier age than non-Hispanic groups, but also at an earlier stage (I-II). Ovarian cancer has the highest mortality among gynecological malignancies in Hispanics, resulting from various factors including unequal access to screening and treatment disparities, such as adherence to treatment and volume-outcome paradigm. Outcomes are paradoxical among Hispanic women, because while a high proportion are diagnosed younger and at early stages, typically associated with improved survival outcomes, they are more likely to not receive the standard of care, which involves more than providing insurance, access, and the services patients need. Inequitable access to care can lead to noticeable differences in health, especially within the Hispanic community in the United States. Our objective is to define access within a conceptual framework of five dimensions—1) approachability; 2) acceptability; 3) availability and accommodation; 4) affordability; and 5) appropriateness—specifically in relation to ovarian cancer disparities in Hispanic women in the US. Utilizing these dimensions, we summarize available knowledge about how inequitable access to care contributes to the underlying disparities that Hispanic women in the US experience, focusing particularly on social determinants of health, as well as adherence to care and the volume-outcome relationship. The health care system needs to develop innovative strategies to educate and inform the surrounding Hispanic communities Despite the limited data available, we summarize the available literature and propose the application of different strategies to help address the potential—systemic, logistic, and geographic—barriers that affect how Hispanic women with ovarian cancer access health care, in order to implement a health care delivery system that is equitable. Citation Format: Claudia B. Schiavo, Guillermo Armaiz. Access to care as a contributing factor to underlying disparities in Hispanic women with ovarian cancer in the United States [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-077.

The Effect of Hospital versus Surgeon Volume on Short Term Patient Outcomes after Pancreaticoduodenectomy: A SEER-medicare Analysis

Introduction: The volume-outcome relationship has been well-established for pancreaticoduodenectomy (PD). It remains unclear if this is primarily driven by hospital volume or individual surgeon experience. The aim of this study was to determine the relationship of hospital and surgeon volume on short-term outcomes in patients with pancreatic adenocarcinoma undergoing PD. Method: Patients >65 years old who underwent PD for pancreatic adenocarcinoma were identified from SEER-Medicare (2008-2015). Analyses were stratified by hospital and surgeon volume and four volume cohorts were created: low-low (low hospital, low surgeon), low-high (low hospital, high surgeon), high-low (high hospital, low surgeon), high-high (high hospital, high surgeon). Propensity scores were created for the odds of undergoing surgery with high volume surgeons. Following matching, multivariate analysis was used to assess the impact of surgeon volume on outcomes. Results: In total, 2450 patients were identified of which 54.3% were treated at high volume hospitals (40.0% low volume surgeons, 60.0% high volume surgeons) and 45.7% were treated at low volume hospitals (45.7% low volume surgeons, 54.3% high volume surgeons). On matched multivariate analysis, there were no significant differences in the risk of major complications, 90-day mortality and 30-day readmission based on surgeon volume within the low and high hospital volume cohorts. Conclusions: As compared to surgeon volume, hospital volume is a more significant factor in predicting short-term outcomes after PD. This suggests that a focus on resources and care pathways, in combination with volume metrics, is more likely to achieve high-quality care for patients undergoing PD across all hospitals.

Centralization of Pancreatic Surgery in Belgium: Results of the First 100 Resections of a Large Non-Academic Center

Introduction: Because of clear volume-outcome relation for complex cancer surgery, Belgian government imposed centralization of pancreatic surgery since 07/2019. Two of the bigger departments of our province managed to overcome the existing competitive atmosphere and turn it into a unique collaboration. Our pancreatic surgery consortium achieved this recognition as one of 15 national centers of reference. Objective: Share our results of first 100 consecutive cases, evaluating the effect of centralizing pancreatic surgery in West-Flanders. Methods: Since 06/2019, all patients with pancreatic cancer are discussed at a MC. All patients considered for surgery were included. Demographics and perioperative data are prospectively stored in the Belgian Cancer Registry. Results: First 100 pancreatic resections have been performed from 07/2019 to 11/2020. Median hospital stay was 11 days. 30/90-day mortality was 1% and 2%. R0 resection was achieved in 86,1%. Clavien-Dindo ≥3 and ≥3b complications were observed in 17% and 11%. POPF (grade B-C), bile leakage, PPH and DGE occurred in 14%, 4%, 10% and 11% respectively. In contrast to presumed drawbacks, an overall improvement was seen: surgical techniques and postoperative care were standardized, co-operators were more familiar with this complex pathology and postoperative morbidity/mortality is decreasing. Conclusion: Centralization of pancreatic surgery in West-Flanders is successful based on early experience and results. Positive effects were seen on patient outcome and experience of health care providers. Number of surgeries have been multiplied and a favorable postoperative morbidity/mortality was observed. This is a unique and successful collaboration and an example for similar initiatives in the future.

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.

Variation in the volume-outcome relationship after rectal cancer surgery in the United States: Retrospective study with implications for regionalization

BackgroundPrevious studies have demonstrated improved outcomes for patients with rectal cancer treated at higher-volume hospitals. However, little is known whether heterogeneity in this effect exists. The objective was to test whether the effect of increased annual rectal cancer resection volume on outcomes is consistent across all hospitals treating rectal cancer. MethodsAdult stage I to III patients who underwent surgical resection for rectal adenocarcinoma from 2004 to 2016 were identified in the National Cancer Database. ResultsWe included 120,522 patients treated at 763 hospitals in this retrospective cohort study. Higher volume was linearly and incrementally related to outcomes in unadjusted analyses. In adjusted models, for an average patient at the average hospital, the effect of increasing the annual caseload of rectal cancer resections by 20 resections per year was associated with 8%, (hazard ratio = 0.92, 95% confidence interval = 0.87, 0.97), 18% (odds ratio = 0.82, 95% confidence interval = 0.70, 0.98), and 16% (odds ratio = 0.84, 95% confidence interval = 0.73, 0.95) relative reductions in 5-year overall survival, 30-, and 90-day mortality, respectively, and with a 19% (odds ratio = 1.19, 95% confidence interval = 1.04, 1.36) relative increase in the rate of neoadjuvant chemoradiation. These effects varied by individual hospitals such that 39% of hospitals do not see any benefit in 5-year overall survival associated with higher volumes. Increased volume was associated with lower positive circumferential resection margin rates at 19% of the hospitals. ConclusionThis study confirms that higher-volume hospitals have improved outcomes after rectal cancer surgery. However, there exists significant variation in these effects induced by individual within-hospital effects. Regionalization policies may need to be flexible in identifying the hospitals that would achieve enhanced benefits from treating a larger volume of patients.

Impact of hospital volume of valve operations on the utilization and outcomes of surgery for patients with infective endocarditis

Valve surgery is indicated and can be life-saving in patients with infective endocarditis (IE). We evaluated the impact of hospital valvular surgery volume on utilization and outcomes of surgery for IE. National Inpatient Sample (NIS) database was used for IE hospitalizations from 2008 to 2015. Hospitals were divided into quartiles based on valve surgery volume with quartile 1 (Q1) indicating lowest volume and quartile 4 (Q4) highest volume. Primary outcome was utilization of valve surgery in patients hospitalized with IE and secondary outcomes were in-hospital mortality and length of stay for IE patients undergoing valve surgery. Volume-outcome relationship was analysed both as categorical (quartiles) and continuous variable (restricted cubic splines). A total of 36 471 hospitalizations for IE were identified using the NIS database from 2008 to 2015 of which 17.33% underwent any valve surgery. Utilization rates of valve surgery for IE were significantly higher in Q4 hospitals (Q1: 6.73%; Q2: 10.39%; Q3: 14.91%; Q4: 2321%). Amongst the admissions for IE endocarditis undergoing valve surgery, there was no significant difference in in-hospital mortality when analysed as a categorical variable (as quartiles). However, when analysed as a continuous variable we note significant variation in outcomes across the Q4 hospitals, with highest volume centres having reduced mortality rates and length of stay. Hospital valvular surgery volume has direct impact on utilization and outcomes of surgery for IE. Given rising rates of IE and ongoing intravenous drug pandemic, there is need for regionalization of care for IE patients and development of 'endocarditis centres of excellence' for improved patient outcomes.