A health technology assessment based on a meta-analysis including direct and indirect comparisons of 5-year weight loss outcome after metabolic surgeries versus a non-surgical approach.

Introduction: Metabolic surgery is the best choice of treatment for patients with overweight; however, choosing an appropriate method remains a challenge for bariatric surgeons.

Evidence acquisition: Based on a literature search in the PubMed database, long-term metabolic and weight loss outcomes of standard care (SC) and different metabolic interventions were collected. Descriptive statistics, initial direct pairwise comparisons using the Ivhet-method and a network meta-analysis (General Pairwise Modelling) on change in Body Mass Index (BMI) and a cost-utility analysis based on the Markov model were performed.

Evidence synthesis: Analysis of the PubMed database identified 1324 unique publications. After rigorous screening, relevant publications were retrieved and 22 studies were enrolled, including a total of 12695 cases. Long-term effectiveness was unsatisfactory after SC. Surgical patients achieved good rates of resolution of comorbidities. All surgical procedures had over 25% of total weight loss (TWL%) and over 60% of excess weight loss (EWL%) at 5 years. Deterministic cost-effectiveness analysis showed the superiority of one-anastomosis gastric bypass (OAGB) (effectiveness: 4.145, cost: €22,484). Sensitivity analysis presented the absolute and relative (to SC) benefit of OAGB. Simple direct pairwise comparisons could not prove the superiority of any treatment modality; however, network meta-analysis in combination with cost-utility analysis showed OAGB to be the most efficient method (OR was 1.36, 1.24 and 1.08 for OAGB, LRYGB and LSG compared to SC, respectively).

Conclusions: Metabolic surgery seems to be a more favourable approach in weight loss management than standard treatment; however, our analysis could not prove the superiority of any kind of surgery.