Cost-effectiveness of endoscopic treatments for obesity: a clinical evidence map and systematic review to inform a model-based cost-effectiveness analysis

Background
Bariatric surgery is the most effective treatment for obesity, but access is limited. Endoscopic obesity treatments are potentially cheaper and less invasive options, which may be similarly effective. There is currently a lack of evidence to inform decisions on whether such treatments should be considered for people living with obesity.

Objective(s)
What is the current evidence for the clinical and cost-effectiveness of endoscopic treatments compared to alternative weight management interventions for obesity?

Methods
Comprehensive searches were undertaken to January 2023 and a searchable evidence map of all quantitative studies (n > 2) on endoscopic treatments was constructed. The map was used where possible to inform the economic models. Indirect comparisons were undertaken where relevant direct evidence for the model was not available. A systematic review of cost-effectiveness studies was undertaken. Targeted searches were undertaken to identify additional evidence to inform model parameters. Three economic (Markov) models were designed to estimate the cost-effectiveness of endoscopic therapies compared to alternative weight management interventions from a United Kingdom National Health Service and Personal Social Services perspective.

Results
The evidence map included over 1500 records of studies of endoscopic therapies, most of which related to intragastric balloons and endoscopic sleeve gastrectomy. Three cost–utility analyses were identified, one of which was set in the United Kingdom and was used to inform the models.

Laparoscopic sleeve gastrectomy is likely cost-effective compared with endoscopic sleeve gastroplasty for patients’ obesity class II and III (£10,593 per quality-adjusted life-year-gained). Endoscopic sleeve gastroplasty is likely cost-effective compared with semaglutide for patients’ obesity class I and II (£7267 per quality-adjusted life-year-gained). Semaglutide is dominant (cheaper and more effective) than intragastric balloon in patients’ obesity class I and II. Probabilistic sensitivity analysis found a degree of confidence in the estimates. The 5-year time horizon may not capture longer-term benefits from endoscopic sleeve gastroplasty or laparoscopic sleeve gastrectomy.

Limitations and conclusions
The effectiveness evidence base was greater and more wide-ranging than anticipated. However, for the interventions compared within the economic models, there were no randomised controlled trials and either limited, or an absence of, direct comparative evidence. There was also limited long-term data on interventions. These limitations necessitated the use of assumptions in modelling.

Future work
Future research should focus on longer-term effectiveness of endoscopic treatments, studies directly comparing endoscopic therapies against semaglutide or other emerging weight loss drugs and studies which better reflect the complex treatment pathways of obesity and different obesity classes. Such studies could provide more robust evidence for informing future cost-effectiveness models beyond a 5-year time horizon.