REBALANCE

REBALANCE: REview of Behaviour And Lifestyle interventions for severe obesity: AN evidenCE synthesis

Adults with severe obesity (body mass index, BMI ≥35kg/m2) have an increased risk of comorbidities, and psychological, social and economic consequences. Systematic review (SR) evidence and economic evaluations on weight management programmes (WMPs) for adults with severe obesity are limited.

The overall aim of this study was to systematically review the evidence for bariatric surgery, lifestyle WMPs and orlistat pharmacotherapy for severe obesity, and evaluate their feasibility, acceptability, effectiveness, and cost-effectiveness.

The health economic objectives were 1) to review the current evidence base on cost-effectiveness and 2) to determine the long term cost-effectiveness of different strategies from an NHS perspective.

Outcome and Translation

N=46 studies were included in the review of cost-effectiveness. Many evaluations were of short duration or did not include extrapolations of input data, failing to fully capture the long term implications of obesity related disease. Modelling assumptions regarding weight regain after the period of weight loss were poorly described, and their impact on long term cost-effectiveness was rarely tested in sensitivity analyses. There was a distinct lack of high quality, long term data on the cost-effectiveness of VLCDs in a UK setting.

Data on the cost-effectiveness of orlistat had mixed results. When compared with WMPs, surgery was found to be cost-effective. When compared with no treatment, surgery was sometimes cost-saving with the savings from reduced obesity related comorbidities found to offset the surgery costs. However, the cost-effectiveness of surgery depended on the quality of the model input data, which were rarely sufficient to fully capture the costs of preparation, delivery, complications and most importantly long term follow-up subsequent to bariatric surgery. None of the studies included any quality of life decrements for surgery related complications, which might over-state the cost-effectiveness case for surgery.

The micro-simulation model was used to address gaps in the current evidence base. The model results show that WMPs were generally cost-effective compared to a baseline ‘do nothing’ approach (ICER <£20,000/QALY). However, the addition of VLCDs to WMPs was not cost-effective. The Look AHEAD programme was borderline cost-effective, with an improved case for cost-effectiveness under more realistic, longer term weight regain assumptions. Roux-en-Y bariatric surgery was the most cost-effective strategy in the base case analysis, over a 30 year time horizon, though the model did not replicate long term cost savings for surgery suggested by some studies in our SR. The economic model results were sensitive to assumptions about weight regain, model time horizon and discount rate for costs and QALYs.

This review is registered with PROSPERO International prospective register of systematic reviews (PROSPERO 2016:CRD42016040190).

HERU researchers involved in this research project: Dwayne Boyers and Elisabet Jacobsen

External collaborators: Avenell, A., Skea, Z., De Bruin, M., MacLennan, G. (HSRU, University of Aberdeen); Aveyard, P. (University of Oxford) and Webber, L (UK Health Forum).

Publications

Avenell, A., Robertson, C., Ske, Z., Jacobsen, E., Boyers, D., Cooper, D., Aceves-Martins, M., Retat, L., Fraser, C., Aveyard, P., Stewart, F., MacLennan, G., Webber, L., Corbould, E., Xu, B., Jaccard, A., Boyle, B., Duncan, E., Shimonovich, M. and de Bruin, M. (2018) REview of Behaviour And Lifestyle interventions for severe obesity: AN evidenCE synthesis (REBALANCE). Systematic reviews and economic evaluations. Final report submitted to NIHR Health Technology Assessment Programme (Project number: 15/09/04).

Avenell, A., Robertson, C., Skea, Z., Jacobsen, E., Boyers, D., Cooper, D., Aceves-Martins, M., Retat, L., Fraser, C., Aveyard, P., Stewart, F., MacLennan, G., Webber, L., Corbould, E., Xu, B., Jaccard, A., Boyle, B., Duncan, E., Shimonovich, M. and Bruin, M. (2018) 'Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation', Health Technology Assessment, 22(68).

Jacobsen, E.Boyers, D. and Avenell, A. (2020) 'Challenges of systematic reviews of economic evaluations: a review of recent reviews and an obesity case study', PharmacoEconomics, 38, 259-267.

Presentations

Jacobsen, E. and Boyers, D. (2018) 'Challenges of cost-effectiveness systematic reviews: REBALANCE study', HTAi Annual Meeting, Vancouver, Canada, 1-5 June 2018.

Boyers, D., Retat, L., Corbould, E., Jacobsen, E., Avenell, A., Xu, B., Jaccard, A., Cooper, D., Robertson, C., Webber, L. and the Rebalance Study Team (2018) 'Economic evaluation of Roux-en-Y bariatric surgery for adults with severe obesity: results from the REBALANCE Project' [poster], 5th UK Congress on Obesity, Newcastle University, Newcastle, England, 6-7 September 2018.

Boyers, D., Retat, L., Corbould, E., Jacobsen, E., Avenell, A., Xu, B., Jaccard, A., Cooper, D., Robertson, C., Webber, L. and the Rebalance Study Team (2018) 'Economic evaluation of weight management for adults with severe obesity: results from the NIHR HTA funded REBALANCE Project', 5th UK Congress on Obesity, Newcastle University, Newcastle, England, 6-7 September 2018.

Jacobsen, E., Boyers, D., Avenell, A., Fraser, C. and the Rebalance Study Team (2018) 'Cost-effective interventions for adults with severe obesity: findings from the REBALANCE systematic review' [poster], 5th UK Congress on Obesity, Newcastle University, Newcastle, England, 6-7 September 2018.

Retat, L., Corbould, E., Boyers, D., Jacobsen, E., Xu, B., Webber, L., Jaccard, A., Avenell, A., Cooper, D., Robertson, C. and the Rebalance Study Team (2018) 'Modelling the epidemiological impact and cost-effectiveness of Look AHEAD in the UK healthcare system: results from the NIHR HTA funded REBALANCE Project' [poster], 5th UK Congress on Obesity, Newcastle University, Newcastle, England, 6-7 September 2018.

Boyers, D., Retat, L., Jacobsen, E., Avenell, A., Corbould, E., Webber, L., De Bruin, M., Robertson, C., Aceves-Martins, M., Cooper, D. and the REBALANCE Study Team. (2019) 'Cost-effectiveness of interventions for the management of severe obesity (findings from the REBALANCE study)' [poster], Public Health Research and Science Conference, University of Manchester, 9-10 April 2019.

Jacobsen, E. and Boyers, D. on behalf of the REBALANCE study team (2019) 'REview of Behaviour And Lifestyle interventions for severe obesity: AN evidenCE synththesis', 7th Annual Research Symposium: Evidence for Value in an Era of Realistic Medicine, COSLA Conference Centre, Edinburgh, 25 April 2019.

Retat, L., Boyers, D.Jacobsen, E., Corbould, E., Webber, L. and Avenell, A. (2019) 'The cost-effectiveness of Very Low Calorie Diets for severe obesity: modelling study in the UK' [poster], 26th European Congress on Obesity, Scottish Event Campus, Glasgow, 28 April - 1 May 2019.