Division of Orthopaedic Surgery, University of Western Ontario, London, Ontario, Canada.
J Arthroplasty. 2018 Jul;33(7S):S32-S38. doi: 10.1016/j.arth.2018.02.031. Epub 2018 Feb 14.
We estimated the cost-effectiveness of performing total knee arthroplasty (TKA) vs nonoperative management (NM) among 6 body mass index (BMI) cohorts.
A Markov model was used to compare the cost-utility of TKA and NM in 6 BMI groups (nonobese [BMI 18.5-24.9], overweight [25-29.9], obese [30-34.9], severely obese [35-39.9], morbidly obese [40-49.9], and super-obese [50+] patients) over a 15-year period. Model parameters for transition probability (ie, revision, re-revision, death), utility, and costs were estimated from the literature. Direct medical costs but not indirect societal costs were included in the model. Costs and utilities were discounted 3% annually. The primary outcome was the incremental cost-effectiveness ratio (ICER) of TKA vs NM. One-way and probabilistic sensitivity analyses of the model parameters were performed to determine the robustness of the model.
Over the 15-year period, the ICERs for the TKA vs NM for the different BMI categories were nonobese ($3317/quality-adjusted life years [QALYs]), overweight ($2837/QALY), obese ($2947/QALY), severely obese ($3536/QALY), morbidly obese ($5531/QALY), and super-obese ($11,878/QALY). The higher BMI groups tended to have higher incremental QALYs and also higher incremental costs. The probabilistic sensitivity analysis with an ICER threshold of $30,000/QALY showed that TKA would be cost-effective in 100% of simulations of patients with a BMI<50 and 99.16% of super-obese simulations.
While performing TKA on super-obese patients is more expensive, the substantial improvements in patient outcomes make it cost-effective. Therefore, withholding TKA care based on a BMI would lead to an unjustified loss of health-care access.
我们评估了在 6 个体重指数（BMI）队列中进行全膝关节置换术（TKA）与非手术治疗（NM）的成本效益。
使用马尔可夫模型比较了 6 个 BMI 组（非肥胖[BMI 18.5-24.9]、超重[25-29.9]、肥胖[30-34.9]、重度肥胖[35-39.9]、病态肥胖[40-49.9]和超级肥胖[50+]患者）在 15 年内 TKA 和 NM 的成本效用。通过文献估计模型参数的转移概率（即翻修、再次翻修、死亡）、效用和成本。模型中仅包含直接医疗成本，不包含间接社会成本。成本和效用按 3%的年率贴现。主要结果是 TKA 与 NM 的增量成本效益比（ICER）。对模型参数进行了单因素和概率敏感性分析，以确定模型的稳健性。
在 15 年内，不同 BMI 类别中 TKA 与 NM 的 ICER 分别为非肥胖（3317 美元/QALY）、超重（2837 美元/QALY）、肥胖（2947 美元/QALY）、重度肥胖（3536 美元/QALY）、病态肥胖（5531 美元/QALY）和超级肥胖（11878 美元/QALY）。BMI 较高的组往往具有较高的增量 QALY 和增量成本。ICER 阈值为 30000 美元/QALY 的概率敏感性分析表明，在 BMI<50 的患者中，TKA 在 100%的模拟中具有成本效益，在超级肥胖患者的模拟中，99.16%具有成本效益。
尽管对超级肥胖患者进行 TKA 手术的费用更高，但患者结局的显著改善使其具有成本效益。因此，基于 BMI 拒绝 TKA 治疗会导致不合理的医疗保健机会丧失。
