Technologies scoping report

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1 Technologies scoping report In response to an enquiry from the National Planning Forum obesity treatment review steering group Number 6 June 2012 What is the relative clinical effectiveness, cost effectiveness and safety of different bariatric surgery techniques (gastric bypass, gastric banding and sleeve gastrectomy)? What is a scoping report? Scoping reports ascertain the quantity and quality of the published clinical and cost effectiveness evidence on health technologies under consideration by decision makers within NHSScotland. They also serve to clarify definitions related to the research question(s) on that topic. They are intended to provide an overview of the evidence base, including gaps and uncertainties, and inform decisions on the feasibility of producing an evidence review product on the topic. Scoping reports are undertaken in an approximately 1 month period. They are based upon a high level literature search and selection of the best evidence that Healthcare Improvement Scotland could identify within the time available. The reports are subject to peer review but do not undergo external consultation. Scoping reports do not make recommendations for NHSScotland. Key definitions BMI: Body mass index. Body weight in kilograms divided by height in metres squared BPD: biliopancreatic diversion LAGB: laparoscopic adjustable gastric band AGB: adjustable gastric band RYGP: Roux-en-Y gastric bypass GBP: gastric bypass T2DM: type 2 diabetes mellitus Background Scotland has one of the highest levels of obesity among developed countries, and there has been a steady rise in prevalence that is likely to continue. It is well established that obesity is associated with ill health including, but not limited to, cardiovascular disease, certain cancers and type 2 diabetes mellitus (T2DM). The Scottish Public Health Observatory estimates that 47% of T2DM can be attributed to obesity (2010) 1. In 2003, it was estimated that the cost of obesity and obesity-related illness to NHSScotland was 171 million 1. A report recently published by the Scottish Government estimates that by 2030 the total cost of obesity to Scottish society (direct and indirect costs) could range from billion 1. The Scottish Intercollegiate Guidelines Network (SIGN) guidelines 2, published in 2010, states that in adults: Bariatric surgery should be considered on an individual case basis following assessment of risk/benefit in patients who fulfil the following criteria: BMI 35 kg/m 2 presence of one or more severe comorbidities which are expected to improve significantly with weight reduction (eg severe mobility problems, arthritis, type 2 diabetes) and evidence of completion of a structured weight management programme involving diet, physical activity, psychological and drug interventions, not resulting in significant and sustained improvement in the comorbidities. There is a need for more guidance on which bariatric procedure should be used for different patient groups. Bariatric procedures have been traditionally described as either restrictive (eg gastric banding or sleeve gastrectomy), malabsorptive, eg biliopancreatic diversion (BPD), or mixed, eg gastric bypass (GBP). These categories are still used in the most recent literature; however it is argued that they are over-simplistic, as no procedure simply affects food intake or absorption in a passive way. There is increasing evidence of hormonal and neural changes associated with different types of surgery. For example, people undergoing so-called malabsorptive procedures do not suffer from chronic diarrhoea; their weight loss is mediated by a series of gut

2 2 hormonal changes which influence appetite, food choices and gut motility amongst other things (A de Beaux, laparoscopic and upper gastrointestinal surgeon, Royal Infirmary of Edinburgh. Personal Communication, 09 Feb 2012). This report is concerned specifically with three procedures: gastric bypass: the Roux-en-Y (RYGP) and resectional gastric bypass procedures involve creating both a small gastric pouch and a bypass that prevents the patient from absorbing all that they have eaten. The procedure can be done laparoscopically or using open surgery. It is technically possible to reverse a gastric bypass 3. gastric banding: this involves laparoscopically placing a band around the upper part of the stomach to create a small pouch to hold food. After surgery, the band can be adjusted to make the food pass more slowly or quickly through the digestive system. It is technically possible to reverse the procedure 3. sleeve gastrectomy: in this approach the stomach is divided vertically to reduce its size to about 25%. It leaves the pyloric valve at the bottom of the stomach intact which means that the stomach function and digestion are unaltered. The sleeve gastrectomy is not reversible 3. The following question was scoped: What is the relative clinical effectiveness, cost effectiveness and safety of different bariatric surgery techniques (gastric bypass, gastric banding and gastric sleeves) among: people who are aged between with a BMI of kg/m 2 and recent (less than 5 years) onset of T2DM people who are aged between with a BMI of kg/m 2 and onset of T2DM of between 8 10 years ago. This question came from the NHSScotland National Planning Forum obesity treatment review steering group. However, comments from clinical experts suggested that such tightly defined groups would be difficult to extract from the literature. Experts who were consulted during the preparation of this report also highlighted that the cut-offs in the question may pick up more women than men. This was based on a recently published paper which suggests that men are diagnosed with T2DM at lower BMI than women across the age range 4. Furthermore, it was highlighted that there should be consideration of lower cut-offs for certain ethnic minorities (South Asians specifically). Consequently, this report has reviewed the literature relating to bariatric surgery and obesity with T2DM generally. Literature search A literature search was conducted during January 2012 to identify recent evidence on the subject of bariatric surgery in patients with T2DM. The searches sought to identify guidelines, health technology assessments (HTA), systematic reviews and primary evidence, including economic studies. Database searches were limited to English language and publications from 2009 to January 2012 to build on the previous searches to support the SIGN obesity guideline 2 and evidence note Evidence base Table 1 Included evidence sources Publication type Number of publications References HTA 2 5,6 Systematic review and meta-analysis Evidence-based guidelines Randomised controlled trial (RCT) Cost-effectiveness analysis 8 3, full publication and 2 conference abstracts 1 6 Cost-utility analysis 2 9,17 Registry data Findings 1 (executive summary only) As predicted, the tightly defined patient groups specified in the question were difficult to differentiate in the literature. This report therefore provides a more general summary of the literature relating to bariatric surgery and obesity with T2DM. The evidence for clinical effectiveness, cost effectiveness and patient safety has been summarised with the relevant patient groups clearly defined. The main outcomes of interest were weight loss and remission or improvement of T2DM. Given the volume of 18

3 3 literature and the short timescales, this report focuses on systematic review evidence from Clinical effectiveness Weight loss The evidence identified that compared the different bariatric procedures in terms of weight loss was not limited to diabetic patients. In a recent systematic review (in two publications) 9,12, including 15 RCTs (1,103 patients) that reported changes in BMI at 1 year, a network meta-analysis was used to rank the interventions in order of efficacy for reducing BMI. The authors included trials that studied severely obese adults with a BMI 40 kg/m 2, or a BMI 35 kg/m 2 and at least one obesity-related comorbidity. Compared with standard care, the mean differences (95% credible interval (CI)) in BMI levels from baseline at 1 year were as follows: jejunoileal bypass: kg/m 2 (95% CI to 0.8) biliopancreatic diversion: kg/m 2 (95% CI to -6.9) mini-gastric bypass: kg/m 2 (95% CI to -4.1) RYGP: -9.0 kg/m 2 (95% CI to -3.1) sleeve gastrectomy: kg/m 2 (95% CI to -2.6) vertical banded gastroplasty: -6.4 kg/m 2 (95% CI to 0.01) horizontal gastroplasty: -5.0 kg/m 2 (95% CI to 1.8) adjustable gastric band: -2.4 kg/m 2 (95% CI -9.1 to 3.9) Based on these results, the authors concluded that mini-gastric bypass, BPD, sleeve gastrectomy and RYGB all reduced BMI to a significantly greater extent than standard care. For jejunoileal bypass, vertical banded gastroplasty, horizontal gastroplasty and adjustable gastric bands (AGBs), the results are not statistically significant. However, the authors also caution that trial quality was generally poor and most studies examined a relatively short time horizon 12. Similar findings were reported in a Cochrane review published in The authors concluded that the limited evidence suggests that weight loss following gastric bypass is greater than vertical banded gastroplasty or adjustable gastric banding, but similar to isolated sleeve gastrectomy and banded gastric bypass. Isolated sleeve gastrectomy appears to result in greater weight loss than adjustable gastric banding 3. The analysis presented in the Cochrane review was undertaken as part of an HTA, also published in Diabetes The most recent systematic review (including literature from ) on the impact of bariatric surgery on T2DM was published in This updates a meta-analysis published by the same authors in 2004, which found that bariatric surgery is followed by resolution of T2DM in 48% of patients who underwent laparoscopic adjustable gastric band (LAGB), 84% of patients who underwent gastric bypass, and 98% of patients who underwent BPD/duodenal switch 19. The dataset for the 2009 review consisted of 621 studies, with 888 treatment arms and 135,246 patients (mean age 40 years, mean baseline BMI 47.9 kg/m 2, 80% female). Of all the included patients, 22.3% had T2DM. In the 621 studies, diabetes resolved in 78.1% of the diabetic patients, and diabetes was improved or resolved in 86.6%. Diabetes resolution was greatest for patients undergoing BPD/duodenal switch (95.1% resolved), followed by gastric bypass (80.3%), gastroplasty (79.7%), and LAGB (56.7%). In studies reporting only patients with diabetes and 2-years follow up, 62% of patients (n=48) remained diabetes free 2 years after surgery 7. The authors of this review reported that the impact on diabetes seemed to be more pronounced in procedures associated with the greatest weight loss. However, they also discussed additional literature that suggests that weight and T2DM are not in a direct cause-and-effect relationship. Postoperative changes in metabolic profile have been shown to occur before the weight is actually lost in some procedures (eg gastric bypass), which may be related to altered responses to gut hormones 7. This does not occur with procedures traditionally described as restrictive (eg gastric banding). Thus the mechanism by which diabetes improves may differ between procedures. There are limitations with this review 7 that should be noted. Most of the included studies were

4 4 lower level evidence (29 RCTs, 49 non-rcts, 60 comparative retrospective series, 187 uncontrolled prospective case series, 266 singlearm retrospective studies, 25 observational studies and two case-control studies). The authors also highlight that there were high attrition rates in the included studies and a diversity of reporting formats for diabetes outcomes. The considerable heterogeneity among the studies should be noted when considering the pooled results. The aforementioned review did not report results for people undergoing sleeve gastrectomy. However, another systematic review published in 2010 considered this patient group 8. This included 27 studies, encompassing 673 patients with a baseline mean BMI of 47.4 kg/m 2 (range ). The mean percentage of excess weight loss was 47.3% (range %), with a mean follow-up of 13.1 months (range 3 36). T2DM resolution was assessed by 26 of the included studies. T2DM had resolved in 66.2% of the patients, improved in 26.9%, and remained stable in 13.1% 8. There is one RCT by Dixon et al. (2008), referred to in a systematic review 13 and a non-systematic review 20, which compared the effects of standard medical therapy with bariatric surgery on glycaemic control. The trial randomised 60 obese patients (BMI kg/ m 2 ) with recently diagnosed T2DM (<2 years) to LAGB or conventional therapy. Progress was reviewed by the bariatric surgical team every 4 6 weeks throughout the duration of the study, and adjustments were made to band volume using standard clinical criteria 21. At 2 years, the remission rate of T2DM was 73% in the surgery group, compared with 13% in the conventional therapy group 20. Regression analysis indicated that remission of T2DM was related to weight loss (R 2 =0.46; p<0.001) 20. One systematic review 5 refers to the results of the Swedish Obese Subjects (SOS) study. This is a non-randomised trial comparing weight loss outcomes in a group of matched surgical and non-surgical patients. There were 4,047 patients enrolled and followed to 2 years; 1,471 surgical participants and 1,444 conventional treatment participants consented to being followed for 20 years. The participants were aged between years, and had a BMI >34 (males) or >38 (females) 5. This appears to be the best currently available evidence regarding the longterm impact of bariatric surgery. This study has reported that the incidence of diabetes was significantly lower, and recovery from diabetes significantly improved, in the surgically treated group compared with the control group at 2 and 10 years 5. At 10 years, gastric bypass patients had greater improvements in mean blood glucose (-10%) and insulin (-54%) values than patients who underwent gastric banding procedures (glucose -0.8%, insulin -25.3%) or vertical banded gastroplasty (glucose -2.5%, insulin -27.2%) 5. With regards to predictors of reversibility of T2DM, the only evidence identified was from a lower quality (limited literature search) systematic review. The authors referred to a follow up study of 840 patients (53 with T2DM) who had undergone LAGB, stating patients with a history of T2DM of less than 5 years have a greater chance of reversal of their T2DM after AGB than patients with a history of longer than 5 years (83% versus 33%) 11. One other systematic review was identified, but it did not add considerably to the evidence already presented 10. A preliminary search and sift of the primary literature ( ) highlighted three additional RCTs Two of these are small (n=27; n=14), and are only available as conference abstracts 14,15. The third included 60 moderately obese people (BMI >25 but <35) who had poorly controlled T2DM. The authors reported that at a 12-month follow up, remission of T2DM was achieved by 93% of patients who received a gastric bypass and 47% who received sleeve gastrectomy (p=0.02) 16. Finally, a large multi-centre RCT, comparing gastric bypass with LAGB in morbid obesity, is underway 22. This is due to publish in Cost effectiveness A report published by the Canadian Agency for Drugs and Technologies in Health (CADTH) (2010) 9 included a systematic review of the economic evidence published to 2009 on bariatric surgery in adults with severe obesity. Eleven economic analyses were identified, and the authors reported that bariatric surgery compared with standard care is associated with incremental cost-effectiveness ratios (ICERs) of between US$5,000 (approximately 3,172) to US$40,000

5 5 ( 25,375), and may be dominant (more effective and less costly) for patients with T2DM. However, they were unable to draw conclusions on the relative cost effectiveness of alternative procedures 9. The authors also conducted a primary economic evaluation to examine the costs and clinical consequences of standard care, RYGB, LAGB, sleeve gastrectomy or BPD in adults with severe obesity from the perspective of the Canadian healthcare system. They reported ICERs of (Canadian dollars) C$21,600 ( 13,712) per QALY to C$37,910 ( 24,066) per QALY at 10 years (for RYGB and LAGB respectively) and C$9,400 ( 5,966) per QALY to C$12,000 ( 7,616) per QALY using a lifetime horizon. In scenario analysis, a more attractive ICER was observed as the proportion of patients with comorbid diseases increased, and bariatric surgery was dominant when only patients with T2DM were considered. Again, the relative cost effectiveness of the alternative procedures could not be established 9. These results may not generalise to the Scottish context. A new economic model was also reported on in a United Kingdom (UK) HTA from The authors considered three patient groups: GBP or AGB in patients with BMI 40; AGB in patients with BMI 30 and <40 with T2DM; and AGB in patients with BMI 30 and <35. Like the 2010 review, the authors reported that compared with non-surgical interventions, bariatric surgery appears to be a cost-effective intervention in moderately to severely obese people 6. A preliminary search and sift of the primary literature ( ) highlighted an additional cost-effectiveness study 17. The authors used a Markov model of disease progression and cost effectiveness for T2DM that followed patients from diagnosis to either death or age 95 years. They separately estimated the cost effectiveness of gastric bypass surgery relative to usual diabetes care and the cost effectiveness of gastric banding surgery relative to usual diabetes care. The authors did not state what the perspective was. Two patient groups were considered: severely obese people (BMI 35 kg/m 2 ) who are newly diagnosed with diabetes (no more than 5 years after diagnosis) and severely obese people with established diabetes (at least 10 years after diagnosis). They reported that bypass surgery had ICERs of US$7,000 per QALY (approximately 4,435) and US$12,000 per QALY (approximately 7,604) for severely obese people with newly diagnosed and established diabetes, respectively. Banding surgery had ICERs of US$11,000 per QALY (approximately 6,972) and US$13,000 per QALY (approximately 8,239) for the respective groups. The authors caution that although the model parameters appear to favour bypass surgery, this may be due to the different characteristics of the people who opt for bypass surgery (eg higher BMI and more comorbidities). Thus they highlight the need for direct trials comparing the two surgeries 17. Patient safety Recent UK registry data reporting on 8,710 bariatric operations (including 3,817 gastric bypass, 2,132 gastric bands and 588 sleeve gastrectomy operations) provides some of the most up-to-date safety data available 18. The observed in-hospital mortality rate after primary surgery was 0.1% overall (0.2% for gastric bypass), and recorded surgical complication rate overall for primary operations was 2.6%. Eighty percent of patients were discharged by the third post-operative day. A systematic review published by CADTH included patient safety data from studies published to They reported that AGB was associated with a higher risk of slippage or dilation (risk difference (RD)=6.1%; 95% CI 1.3 to 11) and procedure conversion or reversals (RD=8.3%; 95% CI 2.8 to 14), and a lower risk of stenosis (RD=15%; 95% CI 8.3 to 22), ulceration (RD=9.9%; 95% CI 4.0 to 16), herniation (RD=4.5%; 95% CI 0.5 to 8.4), and wound infection (RD=6.3%; 95% CI 1.4 to 11) compared with RYGB. AGB was associated with shorter hospital length-of-stay compared with RYGB (mean difference=1.7 days; 95% CI 1.3 to 2.0). 9,18 The authors also conducted a review of outcomes data across time (6 studies) and according to hospital volume (8 studies) and surgeon volume (7 studies). They concluded that higher surgical volumes and increasing experience with bariatric surgical techniques are associated with better clinical outcomes. They described one study in the United States of America that identified thresholds of 100 surgeries per year per surgeon, and 200 surgeries per year per facility, as optimal for a better clinical outcome 9.

6 6 Summary The available data suggests that weight losses are more pronounced with gastric bypass and sleeve gastrectomy, and less so with AGB. AGB is associated with fewer serious adverse side effects, but has a higher risk of slippage/dilation and procedure conversion/reversal compared with the other techniques. There is some evidence to suggest that compared with standard care, certain bariatric procedures are cost-effective methods of reducing diabetes complications in moderately and severely obese people. However, direct trials of clinical effectiveness are needed before the relative cost effectiveness of the procedures can be established. From this initial scope of the literature, it is not clear which bariatric procedure is suited to which patient characteristic, or when in the diabetes illness trajectory bariatric surgery is most successful in improving or resolving T2DM. It is also not clear whether the improvements in diabetes are maintained beyond 10 years. Further work for Healthcare Improvement Scotland While a significant volume of secondary literature was identified, none of it exactly answers the question posed. It is not possible to conclude from the available evidence which bariatric procedure is most appropriate in the specified patient groups. A more extensive literature review is unlikely to answer the question at this time. Equality and diversity Healthcare Improvement Scotland is committed to equality and diversity in respect of the nine equality groups defined by age, disability, gender reassignment, marriage and civil partnership, pregnancy and maternity, race, religion, sex, and sexual orientation. As a scoping report summarises information and does not provide recommendations a full EQIA assessment is not deemed necessary. The process for producing scoping reports will be assessed when available, however no adverse impacts across any of the groups is expected. Acknowledgements Healthcare Improvement Scotland would like to acknowledge the helpful contribution of the following, who gave advice on the content of this scoping report: Mr Andrew de Beaux Consultant General and Upper Gastrointestinal Surgeon NHS Lothian Professor Mike Lean Chair of Human Nutrition School of Medicine University of Glasgow Mr Peter Small Consultant General Surgeon Sunderland Royal Hospital Sunderland NHS Foundation Trust Dr Sara Davies Public Health Consultant Scottish Government Health and Social Care Directorates Professor Naveed Sattar Professor of Metabolic Medicine University of Glasgow Mr Stuart Oglesby Consultant Oesophagogastric and Bariatric Surgeon NHS Fife Mr Duff Bruce Consultant General and Upper Gastro-intestinal Surgeon NHS Grampian Dr Jennifer Logue Clinical Lecturer in Biochemistry and Metabolic Medicine University of Glasgow Healthcare Improvement Scotland development team Joanna Kelly Lead Author Suzanne Wilson Information Scientist Doreen Pedlar Project Co-ordinator Marina Tudor Team Support Administrator Healthcare Improvement Scotland 2012 ISBN

7 7 References 1. NHS Quality Improvement Scotland. Evidence Note 28: Bariatric surgery in adults [online] [cited 2012 Jan 16]; Available from: ashx?docid=dd6e4313-f5dd c1d-a2b6572af2b8&version=-1 2. SIGN. Management of obesity: a national clinical guideline [online] [cited 2012 Jan 17]; Available from: 3. Colquitt JL, Picot J, Loveman E, Clegg AJ. Surgery for obesity [cited 2012 Jan 17]; Available from: 4. Logue J, Walker JJ, Colhoun HM, Leese GP, Lindsay RS, McKnight JA, et al. Do men develop type 2 diabetes at lower body mass indices than women? Diabetologia. 2011;54(12): Medical Advisory Secretariat, Ontario Ministry of Health and Long-Term Care. Bariatric surgery for people with diabetes and morbid obesity: an evidence-based analysis [cited 2012 Mar 26]; Available from: diabetes_bariatric_ pdf 6. Picot J, Jones J, Colquitt JL, Gospodarevskaya E, Loveman E, Baxter L, et al. The clinical effectiveness and cost effectiveness of bariatric (weight loss) surgery for obesity: a systematic review and economic evaluation [cited 2012 Jan 16]; Available from: 7. Buchwald H, Estok R, Fahrbach K, Banel D, Jensen MD, Pories WJ, et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med. 2009;122(3): Gill RS, Birch DW, Shi X, Sharma AM, Karmali S. Sleeve gastrectomy and type 2 diabetes mellitus: a systematic review. Surg Obes Relat Dis. 2010;6(6): Klarenbach S, Padwal R, Wiebe N, Hazel M, Birch D, Manns B, et al. Bariatric surgery for severe obesity: systematic review and economic evaluation [cited 2012 Mar 26]; Available from: Rao RS, Yanagisawa R, Kini S. Insulin resistance and bariatric surgery. Obes Rev. 2012;13(4): Meijer RI, van Wagensveld BA, Siegert CE, Eringa EC, Serne EH, Smulders YM. Bariatric surgery as a novel treatment for type 2 diabetes mellitus: a systematic review. Arch Surg. 2011;146(6): Padwal R, Klarenbach S, Wiebe N, Birch D, Karmali S, Manns B, et al. Bariatric surgery: a systematic review and network meta-analysis of randomized trials. Obes Rev. 2011;2011(12): Dixon JB, Murphy DK, Segel JE, Finkelstein EA. Impact of laparoscopic adjustable gastric banding on type 2 diabetes. Obes Rev. 2012;13(1): Peterli R, Beglinger C, Von FM, Christoffel C, Kern B, Peters T, et al. Improved glucose metabolism 1 year after bariatric surgery: Comparison of laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG)-a prospective randomized trial. Obes Surg. 2010;20(6): Keidar A, Hershkop K, Schweiger C, Weiss R. Preliminary results of prospective randomized controlled study of the effect of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass on resolution of type 2 diabetes mellitus. Obes Surg. 2010;20(6): Lee W-J, Chong K, Ser K-H, Lee Y-C, Chen S-C, Chen J-C, et al. Gastric bypass vs sleeve gastrectomy for type 2 diabetes mellitus: A randomized controlled trial. Arch Surg. 2011;146(2): Hoerger TJ, Zhang P, Segel JE, Kahn HS, Barker LE, Couper S. Cost-effectiveness of bariatric surgery for severely obese adults with diabetes. Diabetes Care. 2010;33(9): National Bariatric Surgery Registry Data Committee. The United Kingdom National Bariatric Surgery Registry: First Registry Report to March 2010 [online] [cited 2012 Mar 26]; Available from: Buchwald H, Avidor Y, Braunwald E, Jensen MD, Pories W, Fahrbach K, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292(14): Cremieux PY, Eapen S, Trask SW, Ghosh A. Weighing the clinical benefits and economic impact of bariatric surgery in morbidly obese patients with diabetes. Canadian Journal of Diabetes. 2011;35(2): Dixon JB, O BP, Playfair J, Chapman L, Schachter LM, Skinner S, et al. Adjustable gastric banding and conventional therapy for type 2 diabetes: a randomized controlled trial. JAMA. 2008;299(3): National Institute for Health Research. BY-BAND. Gastric BYpass or adjustable gastric BANDing surgery to treat morbid obesity: a multi-centre randomised controlled trial [online] [cited 2012 Mar 26]; Available from: