Bariatric surgery for patients with type 2 diabetes mellitus requiring insulin: Clinical outcome and cost-effectiveness analyses.

BACKGROUND: Although bariatric surgery is well established as an effective treatment for patients with obesity and type 2 diabetes mellitus (T2DM), there exists reluctance to increase its availability for patients with severe T2DM. The aims of this study were to examine the impact of bariatric surgery on T2DM resolution in patients with obesity and T2DM requiring insulin (T2DM-Ins) using data from a national database and to develop a health economic model to evaluate the cost-effectiveness of surgery in this cohort when compared to best medical treatment (BMT). METHODS AND FINDINGS: Clinical data from the National Bariatric Surgical Registry (NBSR), a comprehensive database of bariatric surgery in the United Kingdom, were extracted to analyse outcomes of patients with obesity and T2DM-Ins who underwent primary bariatric surgery between 2009 and 2017. Outcomes for this group were combined with data sourced from a comprehensive literature review in order to develop a state-transition microsimulation model to evaluate cost-effectiveness of bariatric surgery versus BMT for patients over a 5-year time horizon. The main outcome measure for the clinical study was insulin cessation at 1-year post-surgery: relative risks (RR) summarising predictive factors were determined, unadjusted, and after adjusting for variables including age, initial body mass index (BMI), duration of T2DM, and weight loss. Main outcome measures for the economic evaluation were total costs, total quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) at willingness-to-pay threshold of GBP£20,000. A total of 2,484 patients were eligible for inclusion, of which 1,847 had 1-year follow-up data (mean age of 51 years, mean initial BMI 47.2 kg/m2, and 64% female). 67% of patients no longer required insulin at 1-year postoperatively: these rates persisted for 4 years. Roux-en-Y gastric bypass (RYGB) was associated with a higher rate of insulin cessation (71.7%) than sleeve gastrectomy (SG; 64.5%; RR 0.92, confidence interval (CI) 0.86-0.99) and adjustable gastric band (AGB; 33.6%; RR 0.45, CI 0.34-0.60; p < 0.001). When adjusted for percentage total weight loss and demographic variables, insulin cessation following surgery was comparable for RYGB and SG (RR 0.97, CI 0.90-1.04), with AGB having the lowest cessation rates (RR 0.55, CI 0.40-0.74; p < 0.001). Over 5 years, bariatric surgery was cost saving compared to BMT (total cost GBP£22,057 versus GBP£26,286 respectively, incremental difference GBP£4,229). This was due to lower treatment costs as well as reduced diabetes-related complications costs and increased health benefits. Limitations of this study include loss to follow-up of patients within the NBSR dataset and that the time horizon for the economic analysis is limited to 5 years. In addition, the study reflects current medical and surgical treatment regimens for this cohort of patients, which may change. CONCLUSIONS: In this study, we observed that in patients with obesity and T2DM-Ins, bariatric surgery was associated with high rates of postoperative cessation of insulin therapy, which is, in turn, a major driver of overall reductions in direct healthcare cost. Our findings suggest that a strategy utilising bariatric surgery for patients with obesity and T2DM-Ins is cost saving to the national healthcare provider (National Health Service (NHS)) over a 5-year time horizon.

Bariatric-Metabolic Surgery Utilisation in Patients With and Without Diabetes: Data from the IFSO Global Registry 2015-2018.

BACKGROUND: Comparative international practice of patients undergoing bariatric-metabolic surgery for type 2 diabetes mellitus (T2DM) is unknown. We aimed to ascertain baseline age, sex, body mass index (BMI) and types of operations performed for patients with T2DM submitted to the IFSO Global Registry. MATERIALS AND METHODS: Cross-sectional analysis of patients having primary surgery in 2015-2018 for countries with ≥90% T2DM data completion and ≥ 1000 submitted records. RESULTS: Fifteen countries including 11 national registries met the inclusion criteria. The rate of T2DM was 24.2% (99,537 of 411,581 patients, country range 12.0-55.1%) and 77.1% of all patients were women. In every country, patients with T2DM were older than those without T2DM (overall mean age 49.2 [SD 11.4] years vs 41.8 [11.9] years, all p < 0.001). Men were more likely to have T2DM than women, odds ratio (OR) 1.68 (95% CI 1.65-1.71), p < 0.001. Men showed higher rates of T2DM for BMI <35 kg/m2 compared to BMI ≥35.0 kg/m2, OR 2.76 (2.52-3.03), p < 0.001. This was not seen in women, OR 0.78 (0.73-0.83), p < 0.001. Sleeve gastrectomy was the commonest operation overall, but less frequent for patients with T2DM, patients with T2DM 54.9% vs without T2DM 65.8%, OR 0.63 (0.63-0.64), p < 0.001. Twelve out of 15 countries had higher proportions of gastric bypass compared to non-bypass operations for T2DM, OR 1.70 (1.67-1.72), p < 0.001. CONCLUSION: Patients with T2DM had different characteristics to those without T2DM. Older men were more likely to have T2DM, with higher rates of BMI <35 kg/m2 and increased likelihood of food rerouting operations.

Bariatric Surgery Worldwide: Baseline Demographic Description and One-Year Outcomes from the Fourth IFSO Global Registry Report 2018.

BACKGROUND: Since 2014, the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) has produced an annual report of all bariatric surgery submitted to the Global Registry. We describe baseline demographics of international practice from the 4th report. METHODS: The IFSO Global Registry amalgamated data from 51 different countries, 14 of which provided data from their national registries. Data were available from 394,431 individual records, of which 190,177 were primary operations performed since 2014. RESULTS: Data were submitted on 72,645 Roux en Y gastric bypass operations (38.2%), 87,467 sleeve gastrectomy operations (46.0%), 14,516 one anastomosis gastric bypass procedures (7.6%) and 9534 gastric banding operations (5.0%) as the primary operation since 2014. The median patient body mass index (BMI) pre-surgery was 41.7 kg m2 (inter-quartile range: 38.3-46.1 kg m2). Following gastric bypass, 84.1% of patients were discharged within 2 days of surgery; and 84.5% of sleeve gastrectomy patients were discharged within 3 days. Assessing operations performed between 2012 and 2016, at one year after surgery, the mean recorded percentage weight loss was 28.9% and 66.1% of those taking medication for type 2 diabetes were recorded as not using them. The proportion of patients no longer receiving treatment for diabetes was highly dependent on weight loss achieved. There was marked variation in access and practice. CONCLUSIONS: A global description of patients undergoing bariatric surgery is emerging. Future iterations of the registry have the potential to describe the operated patients comprehensively.

Bariatric Surgery Worldwide: Baseline Demographic Description and One-Year Outcomes from the Second IFSO Global Registry Report 2013-2015.

BACKGROUND: Five International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) surveys since 1998 have estimated the volume and type of bariatric surgery being done in constituent member countries. These reports did not include baseline demographic descriptions. METHODS: An IFSO Global Registry pilot project in 2014 demonstrated that it was possible to amalgamate large numbers of individual patient data from different local and national database systems. Here we describe demographic data from the second report for 54,490 patients from 31 countries operated in the 3 calendar years 2013-2015 and follow up data from 66,560 of 112,544 patients in 2009-2015. RESULTS: Most procedures (97.8%) were performed laparoscopically and 73.3% (95% CI: 73.0-73.7%, range 54.2 to 80.3%) were female. The average age was 42.0 years (95% CI 41.9-42.1, inter-quartile range 33.0-51.0 years) and the median body mass index was 43.3 kg/m2 (inter-quartile range 39.4-48.8 kg/m2). Before surgery, 22.0% patients had type 2 diabetes (inter-country variation 7.4-63.2%); 31.9% were hypertensive (15.8-92.7%); 17.6% had depression (0.0-46.3%); 27.8% took medication for musculoskeletal pain (0.0-58.9%); 18.9% had sleep apnea (0.0-63.2%); and 29.6% of patients had gastro-esophageal reflux disease (9.1-90.9%). Gastric bypass was the most prevalent operation (49.4%), followed by sleeve gastrectomy (40.7%) and gastric banding (5.5%). The 1-year total weight loss for patients with available data was 30.53% (95% CI: 30.22-30.84%) and in the cohort 2009-15 was 30.4% with a follow-up rate of 59.14%. In the 2009-2015 cohort, 64.7% of patients on treatment for diabetes preoperatively were not on treatment postoperatively. CONCLUSIONS: There is widespread variation in access to surgery and in baseline patient characteristics in the countries submitting data to the IFSO Global Registry.

Developing a risk stratification tool for audit of outcome after surgery for head and neck squamous cell carcinoma.

BACKGROUND: Patients treated surgically for head and neck squamous cell carcinoma (HNSCC) represent a heterogeneous group. Adjusting for patient case mix and complexity of surgery is essential if reporting outcomes represent surgical performance and quality of care. METHODS: A case note audit totaling 1075 patients receiving 1218 operations done for HNSCC in 4 cancer networks was completed. Logistic regression, decision tree analysis, an artificial neural network, and Naïve Bayes Classifier were used to adjust for patient case-mix using pertinent preoperative variables. RESULTS: Thirty-day complication rates varied widely (34%-51%; P < .015) between units. The predictive models allowed risk stratification. The artificial neural network demonstrated the best predictive performance (area under the curve [AUC] 0.85). CONCLUSION: Early postoperative complications are a measurable outcome that can be used to benchmark surgical performance and quality of care. Surgical outcome reporting in national clinical audits should be taking account of the patient case mix.

Generic, simple risk stratification model for heart valve surgery.

BACKGROUND: Heart valve surgery has an associated in-hospital mortality rate of 4% to 8%. This study aims to develop a simple risk model to predict the risk of in-hospital mortality for patients undergoing heart valve surgery to provide information to patients and clinicians and to facilitate institutional comparisons. METHODS AND RESULTS: Data on 32,839 patients were obtained from the Society of Cardiothoracic Surgeons of Great Britain and Ireland on patients who underwent heart valve surgery between April 1995 and March 2003. Data from the first 5 years (n=16,679) were used to develop the model; its performance was evaluated on the remaining data (n=16,160). The risk model presented here is based on the combined data. The overall in-hospital mortality was 6.4%. The risk model included, in order of importance (all P<0.01), operative priority, age, renal failure, operation sequence, ejection fraction, concomitant tricuspid valve surgery, type of valve operation, concomitant CABG surgery, body mass index, preoperative arrhythmias, diabetes, gender, and hypertension. The risk model exhibited good predictive ability (Hosmer-Lemeshow test, P=0.78) and discriminated between high- and low-risk patients reasonably well (receiver-operating characteristics curve area, 0.77). CONCLUSIONS: This is the first risk model that predicts in-hospital mortality for aortic and/or mitral heart valve patients with or without concomitant CABG. Based on a large national database of heart valve patients, this model has been evaluated successfully on patients who had valve surgery during a subsequent time period. It is simple to use, includes routinely collected variables, and provides a useful tool for patient advice and institutional comparisons.

The European Association for Cardio-Thoracic Surgery (EACTS) database: an introduction.

OBJECTIVES: Continuous monitoring of surgical outcomes through benchmarking and the identification of best practices has become increasingly important. A structured approach to data collection, coupled with validation, analysis and reporting, is a powerful tool in these endeavours. However, inconsistencies in standards and practices have made comparisons within and between European countries cumbersome. The European Association for Cardio-Thoracic Surgery (EACTS) has established a large international database with the goals of (i) working with other organizations towards universal data collection and creating a European-wide repository of information on the practice of cardio-thoracic surgery, and (ii) disseminating that information in scientific, peer-reviewed articles. We report on the process of data collection, as well as on an overview of the data in the database. METHODS: The EACTS Database Committee met for the first time in Monaco, September 2002, to establish the ground rules for the process of setting up the database. Subsequently, data have been collected and merged by Dendrite Clinical Systems Ltd. RESULTS: As of December 2008, the database included 1,074,168 patient records from 366 hospitals located in 29 countries. The latest submission from the years 2006-08 included 404,721 records. The largest contributors were the UK (32.0%), Germany (20.9%) and Belgium (7.3%). Isolated coronary bypass surgery was the most frequently performed operation; the proportion of surgical workload that comprised isolated coronary artery bypass grafting varied from country to country: 30% in Spain and almost 70% in Denmark. Isolated valve procedures constituted 12% of all procedures in Norway and 32% in Spain. Baseline demographics showed an increase in the mean age and the percentage of patients that were female over time. Remarkably, the mortality rates for all procedures declined over the period analysed, to 2.2% (95% confidence interval [CI] 2.2-2.3%) for isolated coronary bypass, 3.4% (95% CI 3.3-3.5%) for isolated valve and 6.2% (95% CI 6.0-6.5%) for bypass + valve procedures. CONCLUSION: The EACTS database has proven to be an important step forward in providing opportunities for monitoring cardiac surgical care across Europe. As the database continues to expand, it will facilitate research projects, establish benchmarking standards and identify potential areas for quality improvements.

Total arterial revascularization is safe: multicenter ten-year analysis of 71,470 coronary procedures.

BACKGROUND: The purpose of this study was to assess the use of arterial revascularization and to compare the in-hospital mortality with other CABG grafting strategies. METHODS: A total of 71,470 CABG patients (1992-2001) in 27 centers in the United Kingdom were studied. The proportion of patients with arterial revascularization was compared. In-hospital mortality was compared for various grafting strategies: all-arterial (n = 5,401), all non-all-arterial patients (n = 66,069), one artery any number of veins (n = 49,801). The groups were compared for in-hospital mortality using multivariate logistic regression to assess the independent effect of the grafting strategies on mortality; logistic EuroSCORE-predicted mortality was compared to actual mortality, and all arterial and one artery and veins patients were compared with propensity score analysis. RESULTS: There was a significant increase in the proportion of all-arterial patients over time (3.2% to 11.7%, p < 0.001) with evidence of variability across centers. Crude mortality for all-arterial patients was 2% vs 3% for all non-all-arterial patients (p < 0.001). In multivariate analysis, all-arterial was associated with a slight but insignificant increase in in-hospital mortality (odds ratio [OR] 1.13; [95% confidence interval {CI} 0.86-1.48], p = 0.36). There was a trend toward higher mortality in the all-arterial group when compared with the one artery and veins group (OR 1.19 [95% CI 0.91-1.56], p = 0.10). The one artery and veins group was the only group where actual mortality was significantly lower than predicted by EuroSCORE (p < 0.001). In propensity analysis the mortality was 1.51% for one artery and veins and 1.74% of all-arterial patients (p = 0.56). CONCLUSIONS: The use of arterial grafting has increased over time, varies by center, and appears to be safe in terms of in-hospital mortality.

Risk-adjusted sequential probability ratio tests: applications to Bristol, Shipman and adult cardiac surgery.

OBJECTIVE: To investigate the use of the risk-adjusted sequential probability ratio test in monitoring the cumulative occurrence of adverse clinical outcomes. DESIGN: Retrospective analysis of three longitudinal datasets. SUBJECTS: Patients aged 65 years and over under the care of Harold Shipman between 1979 and 1997, patients under 1 year of age undergoing paediatric heart surgery in Bristol Royal Infirmary between 1984 and 1995, adult patients receiving cardiac surgery from a team of cardiac surgeons in London,UK. MAIN OUTCOME MEASURE: Annual and 30-day mortality rates. RESULTS: Using reasonable boundaries, the procedure could have indicated an 'alarm' in Bristol after publication of the 1991 Cardiac Surgical Register, and in 1985 or 1997 for Harold Shipman depending on the data source and the comparator. The cardiac surgeons showed no significant deviation from expected performance. CONCLUSIONS: The risk-adjusted sequential probability test is simple to implement, can be applied in a variety of contexts, and might have been useful to detect specific instances of past divergent performance. The use of this and related techniques deserves further attention in the context of prospectively monitoring adverse clinical outcomes.

The Association of Coloproctology of Great Britain and Ireland study of large bowel obstruction caused by colorectal cancer.

BACKGROUND: This study was designed to investigate the early outcomes after surgical treatment of malignant large bowel obstruction (MBO) and to identify risk factors affecting operative mortality. METHODS: Data were prospectively collected from 1046 patients with MBO by 294 surgeons in 148 UK hospitals during a 12-month period from April 1998. A predictive model of in-hospital mortality was developed using a 3-level Bayesian logistic regression analysis. RESULTS: The median age of patients was 73 years (interquartile range 64-80). Of the 989 patients having surgery, 91.7% underwent bowel resection with an overall mortality of 15.7%. The multilevel model used the following independent risk factors to predict mortality: age (odds ratio [OR] 1.85 per 10 year increase), American Society of Anesthesiologists grade (OR for American Society of Anesthesiologists grade I versus II,III,IV-V = 3.3,11.7,22.2), Dukes' staging (OR for Dukes' A versus B,C,D = 2.0, 2.1, 6.0), and mode of surgery (OR for scheduled versus urgent, emergency = 1.6, 2.3). A significant interhospital variability in operative mortality was evident with increasing age (variance = 0.004, SE = 0.001, P < 0.001). No detectable caseload effect was demonstrated between specialist colorectal and other general surgeons. CONCLUSIONS: Using prognostic models, it was possible to develop a risk-stratification index that accurately predicted survival in patients presenting with malignant large bowel obstruction. The methodology and model for risk adjusted survival can set the reference point for more accurate and reliable comparative analysis and be used as an adjunct to the process of informed consent.