Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation

Abstract

Background Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences. Objectives Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment. Data sources Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017). Review methods Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000–30,000. Results A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [–20.23 kg, 95% confidence interval (CI) –23.75 to –16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of –4.41 kg (95% CI –5.93 to –2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit. Limitations Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken. Conclusions Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends. Future work Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions. Study registration This study is registered as PROSPERO CRD42016040190. Funding The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.

Socioeconomic factors, body mass index and bariatric surgery: a Swedish nationwide cohort study

“…Obesity, defined as having a body mass index (BMI) of 30 kg/m 2 and over, is one of the major modifiable causes of preventable death in the developed world [1,2]. Conventional interventions for weight loss, such as lifestyle modifications (healthy diet and exercise), have often been ineffective in maintaining a sustained weight loss, particularly in individuals with severe obesity (BMI ≥ 40 kg /m 2 ) [3]. Due to the enormous clinical burden and ineffectiveness of conventional interventions against obesity [4,5], it has been highly needed to develop innovative and cost-effective strategies for the treatment of obesity.…”

Challenges of Systematic Reviews of Economic Evaluations: A Review of Recent Reviews and an Obesity Case Study

“…The objectives of this paper are to describe the current state of practice, identify and discuss the key challenges of conducting SREEs, and suggest methods for improvement based on reflection of our experiences conducting a large SREE for weight loss interventions for severely obese adults (body mass index [BMI] ≥ 35 kg/m 2 ) as part of the REBALANCE (REview of Behaviour And Lifestyle interventions for severe obesity: AN evidenCE synthesis) project [9].…”

“…Full details of the methods, including a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) diagram, and results are reported elsewhere [9]. Briefly, studies conducted alongside trials and decision models that compared costs and outcomes in a single framework were included.…”

“…For example, the REBALANCE de novo model found that results were highly sensitive to weight regain assumptions. However, only a minority of studies in the SREE specified their regain assumptions and fewer still tested them in a SA [9]. It is essential that SREEs identify the most important assumptions, and extract concise information on the impact of these assumptions on results.…”

Tracking physical activity using smart phone apps: assessing the ability of a current app and systematically collecting patient recommendations for future development

“…Bariatric surgery is currently the most effective long-term treatment for severe obesity (particularly in the presence of Type 2 diabetes). However, its cost-efficacy for uncomplicated obesity is debated [3], and even after receiving bariatric surgery 10 to 20% of patients still experience suboptimal long-term weight loss [4,5]. The long-term success of bariatric surgery depends in part on patients' adherence to physical activity recommendations [6][7][8][9], and many patients likely require additional support to follow through on their good intentions.…”