Objective: Class III obesity (body mass index >40 kg/m2 ) is associated with higher complications following total knee replacement (TKR), and weight loss is recommended. We aimed to establish the cost-effectiveness of Roux-en-Y gastric bypass (RYGB), laparoscopic sleeve gastrectomy (LSG), and lifestyle nonsurgical weight loss (LNSWL) interventions in knee osteoarthritis patients with class III obesity considering TKR.
Methods: Using the Osteoarthritis Policy model and data from published literature to derive model inputs for RYGB, LSG, LNSWL, and TKR, we assessed the long-term clinical benefits, costs, and cost-effectiveness of weight-loss interventions for patients with class III obesity considering TKR. We assessed the following strategies with a health care sector perspective: 1) no weight loss/no TKR, 2) immediate TKR, 3) LNSWL, 4) LSG, and 5) RYGB. Each weight-loss strategy was followed by annual TKR reevaluation. Primary outcomes were cost, quality-adjusted life expectancy (QALE), and incremental cost-effectiveness ratios (ICERs), discounted at 3% per year. We conducted deterministic and probabilistic sensitivity analyses to examine the robustness of conclusions to input uncertainty.
Results: LSG increased QALE by 1.64 quality-adjusted life-years (QALYs) and lifetime medical costs by $17,347 compared to no intervention, leading to an ICER of $10,600/QALY. RYGB increased QALE by 0.22 and costs by $4,607 beyond LSG, resulting in an ICER of $20,500/QALY. Relative to immediate TKR, LSG and RYGB delayed and decreased TKR utilization. In the probabilistic sensitivity analysis, RYGB was cost-effective in 67% of iterations at a willingness-to-pay threshold of $50,000/QALY.
Conclusion: For patients with class III obesity considering TKR, RYGB provides good value while immediate TKR without weight loss is not economically efficient.
© 2022 American College of Rheumatology.