University of Edinburgh, Edinburgh, UK.
Edinburgh Orthopaedics, Royal Infirmary of Edinburgh, Edinburgh, UK.
Bone Joint J. 2022 Apr;104-B(4):452-463. doi: 10.1302/0301-620X.104B4.BJJ-2021-0353.R3.
Access to total knee arthroplasty (TKA) is sometimes restricted for patients with severe obesity (BMI ≥ 40 kg/m). This study compares the cost per quality-adjusted life year (QALY) associated with TKA in patients with a BMI above and below 40 kg/m to examine whether this is supported.
This single-centre study compared 169 consecutive patients with severe obesity (BMI ≥ 40 kg/m) (mean age 65.2 years (40 to 87); mean BMI 44.2 kg/m (40 to 66); 129/169 female) undergoing unilateral TKA to a propensity score matched (age, sex, preoperative Oxford Knee Score (OKS)) cohort with a BMI < 40 kg/m in a 1:1 ratio. Demographic data, comorbidities, and complications to one year were recorded. Preoperative and one-year patient-reported outcome measures (PROMs) were completed: EuroQol five-dimension three-level questionnaire (EQ-5D-3L), OKS, pain, and satisfaction. Using national life expectancy data with obesity correction and the 2020 NHS National Tariff, QALYs (discounted at 3.5%), and direct medical costs accrued over a patient's lifetime, were calculated. Probabilistic sensitivity analysis (PSA) was used to model variation in cost/QALY for each cohort across 1,000 simulations.
All PROMs improved significantly (p < 0.05) in both groups without differences between groups. Early complications were higher in BMI ≥ 40 kg/m: 34/169 versus 52/169 (p = 0.050). A total of 16 (9.5%) patients with a BMI ≥ 40 kg/m were readmitted within one year with six reoperations (3.6%) including three (1.2%) revisions for infection. Assuming reduced life expectancy in severe obesity and revision costs, TKA in patients with a BMI ≥ 40 kg/m costs a mean of £1,013/QALY (95% confidence interval £678 to 1,409) more over a lifetime than TKA in patients with BMI < 40 kg/m. In PSA replicates, the maximum cost/QALY was £3,921 in patients with a BMI < 40 kg/m and £5,275 in patients with a BMI ≥ 40 kg/m.
Higher complication rates following TKA in severely obese patients result in a lifetime cost/QALY that is £1,013 greater than that for patients with BMI < 40 kg/m, suggesting that TKA remains a cost-effective use of healthcare resources in severely obese patients where the surgeon considers it appropriate. Cite this article: 2022;104-B(4):452-463.
全膝关节置换术（TKA）的实施有时会受到限制，因为严重肥胖（BMI≥40kg/m²）的患者可能无法接受该手术。本研究比较了 BMI 高于和低于 40kg/m²的 TKA 患者的每质量调整生命年（QALY）成本，以评估该手术的性价比是否合理。
本单中心研究比较了 169 例连续的严重肥胖（BMI≥40kg/m²）患者（平均年龄 65.2 岁（40-87 岁）；平均 BMI 44.2kg/m²（40-66）；129/169 例为女性）与 BMI<40kg/m²的患者接受单侧 TKA 的情况，1：1 进行倾向评分匹配（年龄、性别、术前牛津膝关节评分（OKS））。记录了患者的人口统计学数据、合并症和并发症，随访至 1 年。完成术前和 1 年的患者报告结局测量（PROMs）：欧洲五维健康量表 3 级问卷（EQ-5D-3L）、OKS、疼痛和满意度。利用全国预期寿命数据和肥胖校正以及 2020 年 NHS 国家收费标准，计算了 QALYs（贴现率为 3.5%）和患者一生中的直接医疗费用。使用概率敏感性分析（PSA）对每个队列的成本/QALY 进行了 1000 次模拟的变化模型。
两组患者的所有 PROMs 均显著改善（p<0.05），且两组之间无差异。BMI≥40kg/m²组的早期并发症发生率较高：34/169 例与 52/169 例（p=0.050）。BMI≥40kg/m²组共有 16 例（9.5%）患者在 1 年内再次入院，其中 6 例（3.6%）患者需要再次手术，包括 3 例（1.2%）感染翻修。假设严重肥胖患者的预期寿命缩短和翻修费用增加，BMI≥40kg/m²患者的 TKA 终生成本/QALY 比 BMI<40kg/m²患者高 1013 英镑（95%置信区间 678 至 1409 英镑）。在 PSA 重复中，BMI<40kg/m²患者的最高成本/QALY 为 3921 英镑，BMI≥40kg/m²患者为 5275 英镑。
严重肥胖患者 TKA 后的并发症发生率较高，导致终生成本/QALY 比 BMI<40kg/m²的患者高 1013 英镑，这表明 TKA 仍然是严重肥胖患者有效利用医疗资源的一种方式，前提是外科医生认为这是合理的。
Bhandari M, Bhandari M, et al. The cost per quality-adjusted life year associated with total knee arthroplasty in patients with severe obesity. Bone Joint J. 2022;104-B(4):452-463.
