Title: Systematic review of clinical and cost-effectiveness of endoscopic treatments for obesity to inform a model-based cost-effectiveness analysis
Funder: Department of Health and Social Care

Abstract: Treating obesity offers an opportunity to improve the health and quality of life of people living with obesity and reduce the burden of obesity complications. Treating obesity also has economic benefits to the individual, the NHS, and the wider economy._x000D_ _x000D_ Bariatric (weight loss) surgery remains the most effective obesity treatment that can result in sustained long-term weight loss. Bariatric surgery is associated with the reduction in the risk of death & developing high blood pressure, heart disease, Type 2 diabetes and some cancers. Surgery is also associated with improved quality of life. In patients with Type 2 diabetes, bariatric surgery can result in diabetes remission, improvements in glucose levels and reduction in diabetes complications including heart, foot, kidney and eye diseases. Several studies have shown that bariatric surgery is good value for money for the UK health care system and it is included in the National Institute for Health and Care Excellence (NICE) guidelines._x000D_ _x000D_ However, despite the UK having one of the highest obesity levels in Europe, the number of bariatric surgeries performed in the UK is one of the lowest in Europe. There are several barriers that make patients’ access to surgery difficult including lack of resources, and a postcode lottery in service availability._x000D_ _x000D_ Endoscopic treatments for obesity are weight loss procedures that are delivered without performing major surgery. They rely on passing a tube with a camera down the throat to the stomach without a need for full anaesthesia. There are multiple types of these procedures including ones that insert objects that fill the stomach (e.g. gastric balloons), procedures that restrict the stomach (e.g. endoscopic sleeve), and procedures that aspirate stomach content via a needle through the skin inserted at the time of the endoscopy._x000D_ _x000D_ These endoscopic treatments are likely to be cheaper & require less time in hospital than bariatric surgery. In addition, these procedures can be appropriate for people who cannot tolerate full anaesthesia. These procedures might be more easily accessible compared with bariatric surgery and might be more acceptable to patients as they are less invasive._x000D_ _x000D_ We therefore aim to conduct a wide-ranging systematic search of the published literature & conduct an economic evaluation to answer the following question: “What is the current state of the evidence for endoscopic treatments for obesity and are they good value for money?”. _x000D_ We have assembled a team that has all the necessary expertise to do this & an oversight committee that consists of international experts in obesity, bariatric surgery & obesity endoscopic treatments including clinicians, surgeons, dieticians, commissioners and patients’ representatives. _x000D_ _x000D_ One person living with obesity is a co-investigator and two people living with obesity will be on the oversight committee. The co-investigator will aid the conduct of the study, and dissemination of results, and will be offered the chance to participate in the research (e.g. reviewing the literature). The patient representatives will also lead meetings with people living with obesity & will feedback to the steering committee. All patient representatives contributed to the plain English summary. _x000D_ _x000D_ The findings of the research will be disseminated widely through papers, webinars, international/national presentations, patient organisations, policy makers, NICE, specialist societies & local commissioning leads.

Lay abstract: Background:_x000D_ _x000D_ Obesity has negative impacts on health, the NHS and the wider economy. Bariatric surgery (BS) is currently the most effective obesity treatment resulting in sustained long-term weight loss and improvements in obesity complications and quality of life. NICE clinical guidance 189 recommended the use of BS as a treatment option in patients with body mass index = 35 kg/m2 who fulfil certain criteria. However, the number of BS performed in the UK is one of the lowest in Europe. This is due to multiple factors including limited resources leading to reduced commissioning and a post code lottery in service provision, among others. Endoscopic bariatric treatments have been increasingly available worldwide but not in the UK. These treatments are cheaper than BS, require shorter hospital stay and do not require full anaesthesia, which makes them a bridge, or potentially even an alternative, to BS and could address some of the barriers to accessing treatment in the NHS. The research brief details the need for an overarching evidence synthesis to establish the clinical and cost-effectiveness of endoscopic obesity treatments that are currently available and could be considered for use in the UK._x000D_ _x000D_ Research question: _x000D_ _x000D_ What is the current evidence for the clinical and cost- effectiveness of endoscopic treatments for obesity?_x000D_ _x000D_ Objectives and methods: _x000D_ _x000D_ We will answer the research question by synthesising clinical and cost- effectiveness evidence and conducting a model-based economic evaluation._x000D_ _x000D_ Study design:_x000D_ _x000D_ - Systematic review (SR) of clinical effectiveness:_x000D_ + Based on randomised, non-randomised controlled and uncontrolled studies_x000D_ + Meta-analyses and sub-group analyses (e.g. based on Type 2 diabetes (T2D) status, age groups, ethnicities) will be performed if possible_x000D_ + Network meta-analysis (NMA) may be performed if the assumptions of the NMA model are met_x000D_ + Outputs will include an evidence map and identify unmet research needs. Outputs will also be used where possible to inform the economic model._x000D_ _x000D_ - SR of cost-effectiveness and model based economic evaluations._x000D_ _x000D_ - Model-based cost-effectiveness analysis comparing endoscopic treatments with other alternative treatments: _x000D_ + Development of new model or adaption of existing published model _x000D_ + Analysis from the UK NHS perspective and informed by the SRs of clinical and cost-effectiveness studies._x000D_ + Deterministic and probabilistic sensitivity analysis to explore the robustness of the results._x000D_ _x000D_ We will include any type of endoscopic treatment, compared with any other treatment (including alternative endoscopic treatments). All age groups will be included, and we will distinguish where possible between people aged <12, <21, >21 and > 60 years. Weight change related outcomes will be relevant, as well as adverse events, impact on co-morbidities, further bariatric surgery, mortality, quality of life and cost-effectiveness (for example using Quality Adjusted Life Years (QALYs))._x000D_ _x000D_ Timelines for delivery: 15 months_x000D_ _x000D_ Anticipated impact and dissemination: _x000D_ _x000D_ The evidence reviews, and economic analyses will influence clinical guidelines and commissioning of endoscopic treatments for obesity. The project outputs will be disseminated to health care practitioners, patients, commissioners and policy makers to make informed decisions regarding endoscopic treatments for obesity.

Research activity codes: 6.4 SURGERY
Health categories: CANCER AND NEOPLASMS;CARDIOVASCULAR;METABOLIC AND ENDOCRINE;ORAL AND GASTROINTESTINAL;STROKE