Cardiac rehabilitation versus standard care after aortic aneurysm repair (Aneurysm CaRe): study protocol for a randomised controlled trial.

BACKGROUND: Abdominal and thoracic aortic aneurysms (A/TAA) are an important cause of mortality amongst the older population. Although A/TAA repair can be performed with low peri-operative risk, overall life expectancy remains poor in the years that follow surgery. The majority of deaths are caused by heart attack or stroke, which can both be prevented by cardiac rehabilitation (CR) in patients with clinically-manifest coronary artery disease. A Cochrane review has urged researchers to widen the use of CR to other populations with severe cardiovascular risk, and patients surviving A/TAA repair appear ideal candidates. However, it is unknown whether CR is feasible or acceptable to A/TAA patients, who are a decade older than those currently enrolling in CR. Aneurysm-CaRe is a feasibility randomised controlled trial (RCT) that will address these issues. METHODS AND DESIGN: Aneurysm-CaRe is a pilot RCT of CR versus standard care after A/TAA repair, with the primary objectives of estimating enrolment to a trial of CR after A/TAA repair and estimating compliance with CR amongst patients with A/TAA. Aneurysm-CaRe will randomise 84 patients at two sites. Patients discharged from hospital after elective A/TAA repair will be randomised to standard care or enrolment in their local CR programme with a protocolised approach to medical cardiovascular risk reduction. The primary outcome measures are enrolment in the RCT and compliance with CR. Secondary outcomes will include phenotypic markers of cardiovascular risk and smoking cessation, alongside disease-specific and generic quality-of-life measures. TRIAL REGISTRATION: ISRCTN 65746249 5 June 2014.

Research activity and the association with mortality.

INTRODUCTION: The aims of this study were to describe the key features of acute NHS Trusts with different levels of research activity and to investigate associations between research activity and clinical outcomes. METHODS: National Institute for Health Research (NIHR) Comprehensive Clinical Research Network (CCRN) funding and number of patients recruited to NIHR Clinical Research Network (CRN) portfolio studies for each NHS Trusts were used as markers of research activity. Patient-level data for adult non-elective admissions were extracted from the English Hospital Episode Statistics (2005-10). Risk-adjusted mortality associations between Trust structures, research activity and, clinical outcomes were investigated. RESULTS: Low mortality Trusts received greater levels of funding and recruited more patients adjusted for size of Trust (n = 35, 2,349 £/bed [95% CI 1,855-2,843], 5.9 patients/bed [2.7-9.0]) than Trusts with expected (n = 63, 1,110 £/bed, [864-1,357] p<0.0001, 2.6 patients/bed [1.7-3.5] p<0.0169) or, high (n = 42, 930 £/bed [683-1,177] p = 0.0001, 1.8 patients/bed [1.4-2.1] p<0.0005) mortality rates. The most research active Trusts were those with more doctors, nurses, critical care beds, operating theatres and, made greater use of radiology. Multifactorial analysis demonstrated better survival in the top funding and patient recruitment tertiles (lowest vs. highest (odds ratio & 95% CI: funding 1.050 [1.033-1.068] p<0.0001, recruitment 1.069 [1.052-1.086] p<0.0001), middle vs. highest (funding 1.040 [1.024-1.055] p<0.0001, recruitment 1.085 [1.070-1.100] p<0.0001). CONCLUSIONS: Research active Trusts appear to have key differences in composition than less research active Trusts. Research active Trusts had lower risk-adjusted mortality for acute admissions, which persisted after adjustment for staffing and other structural factors.

Mortality from ruptured abdominal aortic aneurysms: clinical lessons from a comparison of outcomes in England and the USA.

BACKGROUND: The outcome of patients with ruptured abdominal aortic aneurysm (rAAA) varies by country. Study of practice differences might allow the formulation of pathways to improve care. METHODS: We compared data from the Hospital Episode Statistics for England and the Nationwide Inpatient Sample for the USA for patients admitted to hospital with rAAA from 2005 to 2010. Primary outcomes were in-hospital mortality, mortality after intervention, and decision to follow non-corrective treatment. In-hospital mortality and the rate of non-corrective treatment were analysed by binary logistic regression for each health-care system, after adjustment for age, sex, year, and Charlson comorbidity index. FINDINGS: The study included 11,799 patients with rAAA in England and 23,838 patients with rAAA in the USA. In-hospital mortality was lower in the USA than in England (53·05% [95% CI 51·26-54·85] vs 65·90%; p<0·0001). Intervention (open or endovascular repair) was offered to a greater proportion of cases in the USA than in England (19,174 [80·43%] vs 6897 [58·45%]; p<0·0001) and endovascular repair was more common in the USA than in England (4003 [20·88%] vs 589 [8·54%]; p<0·0001). Postintervention mortality was similar in both countries (41·77% for England and 41·65% for USA). These observations persisted in age-matched and sex-matched comparisons. In both countries, reduced mortality was associated with increased use of endovascular repair, increased hospital caseload (volume) for rAAA, high hospital bed capacity, hospitals with teaching status, and admission on a weekday. INTERPRETATION: In-hospital survival from rAAA, intervention rates, and uptake of endovascular repair are lower in England than in the USA. In England and the USA, the lowest mortality for rAAA was seen in teaching hospitals with larger bed capacities and doing a greater proportion of cases with endovascular repair. These common factors suggest strategies for improving outcomes for patients with rAAA. FUNDING: None.

Elective open suprarenal aneurysm repair in England from 2000 to 2010 an observational study of hospital episode statistics.

BACKGROUND: Open surgery is widely used as a benchmark for the results of fenestrated endovascular repair of complex abdominal aortic aneurysms (AAA). However, the existing evidence stems from single-centre experiences, and may not be reproducible in wider practice. National outcomes provide valuable information regarding the safety of suprarenal aneurysm repair. METHODS: Demographic and clinical data were extracted from English Hospital Episodes Statistics for patients undergoing elective suprarenal aneurysm repair from 1 April 2000 to 31 March 2010. Thirty-day mortality and five-year survival were analysed by logistic regression and Cox proportional hazards modeling. RESULTS: 793 patients underwent surgery with 14% overall 30-day mortality, which did not improve over the study period. Independent predictors of 30-day mortality included age, renal disease and previous myocardial infarction. 5-year survival was independently reduced by age, renal disease, liver disease, chronic pulmonary disease, and known metastatic solid tumour. There was significant regional variation in both 30-day mortality and 5-year survival after risk-adjustment. Regional differences in outcome were eliminated in a sensitivity analysis for perioperative outcome, conducted by restricting analysis to survivors of the first 30 days after surgery. CONCLUSIONS: Elective suprarenal aneurysm repair was associated with considerable mortality and significant regional variation across England. These data provide a benchmark to assess the efficacy of complex endovascular repair of supra-renal aneurysms, though cautious interpretation is required due to the lack of information regarding aneurysm morphology. More detailed study is required, ideally through the mandatory submission of data to a national registry of suprarenal aneurysm repair.

Studies using English administrative data (Hospital Episode Statistics) to assess health-care outcomes--systematic review and recommendations for reporting.

BACKGROUND: Studies using English administrative data from the Hospital Episode Statistics (HES) are increasingly used for the assessment of health-care quality. This study aims to catalogue the published body of studies using HES data to assess health-care outcomes, to assess their methodological qualities and to determine if reporting recommendations can be formulated. METHODS: Systematic searches of the EMBASE, Medline and Cochrane databases were performed using defined search terms. Included studies were those that described the use of HES data extracts to assess health-care outcomes. RESULTS: A total of 148 studies were included. The majority of published studies were on surgical specialties (60.8%), and the most common analytic theme was of inequalities and variations in treatment or outcome (27%). The volume of published studies has increased with time (r = 0.82, P < 0.0001), as has the length of study period (r = 0.76, P < 0.001) and the number of outcomes assessed per study (r = 0.72, P = 0.0023). Age (80%) and gender (57.4%) were the most commonly used factors in risk adjustment, and regression modelling was used most commonly (65.2%) to adjust for confounders. Generic methodologic data were better reported than those specific to HES data extraction. For the majority of parameters, there were no improvements with time. CONCLUSIONS: Studies published using HES data to report health-care outcomes have increased in volume, scope and complexity with time. However, persisting deficiencies related to both generic and context-specific reporting have been identified. Recommendations have been made to improve these aspects as it is likely that the role of these studies in assessing health care, benchmarking practice and planning service delivery will continue to increase.

Epidemiological study of provision of cholecystectomy in England from 2000 to 2009: retrospective analysis of Hospital Episode Statistics.

BACKGROUND: The aim of this study was to report the trends in provision of cholecystectomy in the National Health System in England over the 9 year period from 2000 to 2009 and to determine the major risk factors associated with subsequent poor outcome. METHODS: The Hospital Episode Statistics database was interrogated to identify all cholecystectomy procedures for biliary stone disease in adult patients (>16 years). Multivariate regression analyses were used to identify independent predictors of in-patient death, 1 year death, conversion to open, major bile duct injury (BDI) requiring operative repair, and length of stay. RESULTS: A total of 418,214 cholecystectomy procedures for biliary stone disease were identified. Laparoscopic surgery was used in 348,311 (83.3%) cases and increased by 14.6% over the study period. The in-patient mortality rate (0.2%), 1 year mortality rate (1%), proportion of cases converted to open (5.0%), major BDI rate (0.4%), and mean length of stay (3 days) all decreased over the study period. 52,242 (12.5%) cases were carried out during an emergency admission and uptake has remained stable over the decade. Emergency surgery was more likely to be performed at high-volume centres (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.35-1.44) and specialist units (OR 1.32, 95% CI 1.30-1.35). High-volume centres were more likely to complete emergency cases laparoscopically (OR 1.11, 95% CI 1.05-1.18). Multivariate regression analysis demonstrated that patient- (male gender, increasing age, and comorbidity) and disease-specific (inflammatory pathology and emergency admission) factors rather than hospital institutional characteristics (annual cholecystectomy volume and presence of specialist surgical units) were associated with poorer outcomes. CONCLUSIONS: The provision of laparoscopic cholecystectomy in England has increased. This has been associated with improvements in outcomes such as mortality and length of stay. However, emergency cholecystectomy uptake remains sub-optimal and is more likely to be performed at high-volume or specialist hospitals without adverse outcomes. Further research into the routine provision of emergency cholecystectomy in England is needed in order to optimize patient outcomes.

Predictive value of peak systolic velocity for the development of graft limb complications after endovascular aneurysm repair.

PURPOSE: To determine the role of peak systolic velocity (PSV) data provided by duplex ultrasound (DUS) surveillance in the prediction of endograft limb complications after endovascular aneurysm repair (EVAR). METHODS: All 478 consecutive patients (425 men; mean age 75±7 years) who underwent infrarenal EVAR between 2004 and 2010 had DUS scans at 1.5, 3, 6, 9, 12, and 18 months and annually thereafter over a median follow-up of 43 months (range 1-92). In a retrospective study, the PSV recorded from the proximal and distal regions of each stent-graft limb was extracted from each postoperative DUS scan for each patient up to the penultimate scan before diagnosis of a limb complication (limb occlusion, symptomatic or hemodynamically significant kinking, or hemodynamically significant DUS-defined stenosis) requiring reintervention. The median (range) PSV readings from the proximal and distal regions of each stent-graft limb over the course of follow-up were compared between patients who developed a limb complication (n = 38) and those who did not (n = 440). Time-dependent Cox proportional hazards modeling was performed after risk adjustment; results are presented as the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: In the proximal stent-graft limb segment, the median PSV was 106 cm/s (42-308) in patients without limb complications vs. 121 cm/s (50-281) in those with limb complications. Corresponding values in the distal segment of the endograft limb were 113 cm/s (35-400) vs. 129 cm/s (58-420). After risk adjustment, increased PSV over time within both the proximal and distal segments of the stent-graft limb was significantly associated with the risk of limb complications (proximal HR 1.015, 95% CI 1.003 to 1.028, p = 0.014; distal HR 1.010, 95% CI 1.001 to 1.020, p = 0.025). CONCLUSION: Increases in the peak systolic velocity in stent-graft limbs were associated with an increased risk of limb complication, though no predictive threshold could be identified from scans prior to the development of a complication. This observation requires external validation and further investigation to define its clinical utility.

The prevalence of neovascularity in patients clinically diagnosed with rotator cuff tendinopathy.

BACKGROUND: Shoulder dysfunction is common and pathology of the rotator cuff tendons and subacromial bursa are considered to be a major cause of pain and morbidity. Although many hypotheses exist there is no definitive understanding as to the origin of the pain arising from these structures. Research investigations from other tendons have placed intra-tendinous neovascularity as a potential mechanism of pain production. The prevalence of neovascularity in patients with a clinical diagnosis of rotator cuff tendinopathy is unknown. As such the primary aim of this pilot study was to investigate if neovascularity could be identified and to determine the prevalence of neovascularity in the rotator cuff tendons and subacromial bursa in subjects with unilateral shoulder pain clinically assessed to be rotator cuff tendinopathy. The secondary aims were to investigate the association between the presence of neovascularity and pain, duration of symptoms, and, neovascularity and shoulder function. METHODS: Patients with a clinical diagnosis of unilateral rotator cuff tendinopathy referred for a routine diagnostic ultrasound (US) scan in a major London teaching hospital formed the study population. At referral patients were provided with an information document. On the day of the scan (on average, at least one week later) the patients agreeing to participate were taken through the consent process and underwent an additional clinical examination prior to undergoing a bilateral grey scale and colour Doppler US examination (symptomatic and asymptomatic shoulder) using a Philips HDI 5000 Sono CT US machine. The ultrasound scans were performed by one of two radiologists who recorded their findings and the final assessment was made by a third radiologist blinded both to the clinical examination and the ultrasound examination. The findings of the radiologists who performed the scans and the blinded radiologist were compared and any disagreements were resolved by consensus. RESULTS: Twenty-six patients agreed to participate and formed the study population. Of these, 6 subjects were not included in the final assessment following the pre-scan clinical investigation. This is because one subject had complete cessation of symptoms between the time of the referral and entry into the trial. Another five had developed bilateral shoulder pain during the same period. The mean age of the 20 subjects forming the study population was 50.2 (range 32-69) years (SD = 10.9) and the mean duration of symptoms was 22.6 (range .75 to 132) months (SD = 40.1). Of the 20 subjects included in the formal analysis, 13 subjects (65%) demonstrated neovascularity in the symptomatic shoulder and 5 subjects (25%) demonstrated neovascularity in the asymptomatic shoulder. The subject withdrawn due to complete cessation of symptoms was not found to have neovascularity in either shoulder and of the 5 withdrawn due to bilateral symptoms; two subjects were found to have signs of bilateral neovascularity, one subject demonstrated neovascularity in one shoulder and two subjects in neither shoulder. CONCLUSIONS: This study demonstrated that neovascularity does occur in subjects with a clinical diagnosis of rotator cuff tendinopathy and to a lesser extent in asymptomatic shoulders. In addition, the findings of this investigation did not identify an association between the presence of neovascularity; and pain, duration of symptoms or shoulder function. Future research is required to determine the relevance of these findings.

Effect of endovascular aneurysm repair on the volume-outcome relationship in aneurysm repair.

BACKGROUND: We aim to quantify the relationship between the annual caseload (volume) and outcome from elective endovascular (EVR) or open repair of abdominal aortic aneurysms (AAAs) in England between 2005 and 2007. METHODS AND RESULTS: Individual patient data were obtained from the Hospital Episode Statistics. Statistical methods included multiple logistic regression models, mortality control charts, and safety plots to determine the nature of any relationship between volume and outcome. The case-mix between hospitals of different sizes was examined using observed and expected values for in-hospital mortality. Outcome measures included in-hospital mortality and hospital length of stay. Between 2005 and 2007, a total of 57 587 patients were admitted to hospitals in England with a diagnosis of AAA, and 11 574 underwent AAA repair. There were 7313 elective AAA repairs, of which 5668 (78%) were open and 1645 (22%) were EVR. In-hospital mortality rates were 5.63% for all elective AAA repairs with rates of 6.18% for open repair and 3.77% for EVR (odds ratio, 0.676; 95% CI, 0.501 to 0.913; P=0.011). High-volume aneurysm services were associated with significantly lower mortality rates overall (0.991; 0.988 to 0.994; P<0.0001), for open repairs (0.994; 0.991 to 0.998; P=0.0008), and EVR (0.989; 0.982 to 0.995; P=0.0007). Large endovascular units had low mortality rates for open repairs. CONCLUSIONS: A strong relationship existed between the volume of surgery performed and outcome from both open and endovascular aneurysm repairs. These data support the concept that abdominal aortic surgery should be performed in specialized units that meet a minimum volume threshold.

Meta-analysis and systematic review of the relationship between surgeon annual caseload and mortality for elective open abdominal aortic aneurysm repairs.

OBJECTIVE: To assess the relationship between the annual caseload of elective open abdominal aortic aneurysm (AAA) repairs performed by individual surgeons and mortality. METHODS: PubMed, EMBASE, and the Cochrane library were searched for articles on the volume-outcome relationship in AAA surgery. The review conformed to the QUOROM statement. The data were meta-analyzed to compare the mortality rates of higher- and lower-volume surgeons. A critical volume threshold was calculated for better practice. RESULTS: Fourteen relevant articles were retrieved from the searches. A systematic review was performed, and six were meta-analyzed. A total of 115,273 elective open AAA repairs were considered, with a mean mortality rate of 5.56%. Significant relationships between higher surgeon caseload and lower mortality were demonstrated in 12 of 14 studies. From the meta-analysis, the pooled effect estimate was an odds ratio of 0.56 (95% confidence interval, 0.54-0.57) in favor of higher-volume surgeons. A critical volume threshold was identified as 13 cases per annum for individual surgeons. CONCLUSIONS: As surgeons performed higher annual volumes of elective open AAA repairs, significantly lower mortality rates were demonstrated. Surgeons wishing to perform elective AAA repairs should achieve a minimum case volume of 13 repairs per annum.

Surgical mortality score: risk management tool for auditing surgical performance.

Existing methods of risk adjustment in surgical audit are complex and costly. The present study aimed to develop a simple risk stratification score for mortality and a robust audit tool using the existing resources of the hospital Patient Administration System (PAS) database. This was an observational study for all patients undergoing surgical procedures over a two-year period, at a London university hospital. Logistic regression analysis was used to determine predictive factors of in-hospital mortality, the study outcome. Odds ratios were used as weights in the derivation of a simple risk-stratification model-the Surgical Mortality Score (SMS). Observed-to-expected mortality risk ratios were calculated for application of the SMS model in surgical audit. There were 11,089 eligible cases, under five surgical specialties (maxillofacial, orthopedic, renal transplant/dialysis, general, and neurosurgery). Incomplete data were 3.7% of the total, with no evidence of systematic underreporting. The SMS model was well calibrated [Hosmer-Lemeshow C-statistic: development set (3.432, p = 0.33), validation set (6.359, p = 0.10) with a high discriminant ability (ROC areas: development set [0.837, S.E.=0.013] validation set [0.816, S.E. = 0.016]). Subgroup analyses confirmed that the model can be used by the individual specialties for both elective and emergency cases. The SMS is an accurate risk- stratification model derived from existing database resources. It is simple to apply as a risk-management, screening tool to detect aberrations from expected surgical outcomes and to assist in surgical audit.

Operative mortality in colorectal cancer: prospective national study.

OBJECTIVE: To develop a mathematical model that will predict the probability of death after surgery for colorectal cancer. DESIGN: Descriptive study using routinely collected clinical data. DATA SOURCE: The database of the Association of Coloproctology of Great Britain and Ireland (ACPGBI), encompassing 8077 patients with a new diagnosis of colorectal cancer in 73 hospitals during a 12 month period. STATISTICAL ANALYSIS: A three level hierarchical logistic regression model was used to identify independent predictors of operative mortality. The model was developed on 60% of the patient population and its validity tested on the remaining 40%. RESULTS: Overall postoperative mortality was 7.5% (95% confidence interval 6.9% to 8.1%). Independent predictors of death were age, American Society of Anesthesiology (ASA) grade, Dukes's stage, urgency of the operation, and cancer excision. When tested the predictive model showed good discrimination (area under the receiver operating characteristic curve = (0.775) and calibration (comparison of observed with expected mortality across different procedures; Hosmer-Lemeshow statistic = 6.34, 8 df, P = 0.610). CONCLUSIONS: Clinicians can predict postoperative death by using a simple numerical table derived from the statistical model of the ACPGBI. The model can be used in everyday practice for preoperative counselling of patients and their carers as a part of multidisciplinary care. It may also be used to compare the outcomes between multidisciplinary teams for colorectal cancer.

Mortality control charts for comparing performance of surgical units: validation study using hospital mortality data.

OBJECTIVE: To design and validate a statistical method for evaluating the performance of surgical units that adjusts for case volume and case mix. DESIGN: Validation study using routinely collected data on in-hospital mortality. DATA SOURCES: Two UK databases, the ASCOT prospective database and the risk scoring collaborative (RISC) database, covering 1042 patients undergoing surgery in 29 hospitals for gastro-oesophageal cancer between 1995 and 2000. STATISTICAL ANALYSIS: A two level hierarchical logistic regression model was used to adjust each unit's operative mortality for case mix. Crude or adjusted operative mortality was plotted on mortality control charts (a graphical representation of surgical performance) as a function of number of operations. Control limits defined as 90%, 95%, and 99% confidence intervals identified units whose performance diverged significantly from the mean. RESULTS: The mean in-hospital mortality was 12% (range 0% to 50%). The case volume of the units ranged from one to 55 cases a year. When crude figures were plotted on the mortality control chart, four units lay outside the 90% control limit, including two outside the 95% limit. When operative mortality was adjusted for risk, three units lay outside the 90% limit and one outside the 95% limit. The model fitted the data well and had adequate discrimination (area under the receiver operating characteristics curve 0.78). CONCLUSIONS: The mortality control chart is an accurate, risk adjusted means of identifying units whose surgical performance, in terms of operative mortality, diverges significantly from the population mean. It gives an early warning of divergent performance. It could be adapted to monitor performance across various specialties.