Centre for Health Services and Policy Research, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada.
Foot Ankle Int. 2021 May;42(5):624-632. doi: 10.1177/1071100720977842. Epub 2021 Jan 27.
Ankle replacement and ankle arthrodesis are standard treatments for treating end-stage ankle arthritis when conservative treatment fails. Comparing patient-reported outcome scores to the instrument's minimal important difference (MID) helps physicians and researchers infer whether a meaningful change in health from the patient's perspective has occurred following treatment. The objective of this study was to estimate the MID of the Ankle Osteoarthritis Scale among a cohort of operatively treated end-stage ankle arthritis patients undergoing ankle replacement or arthrodesis.
A survey package including the Ankle Osteoarthritis Scale was completed by participants preoperatively and 2 years postoperatively. Distribution and anchor-based approaches to calculating the MID were used to estimate the MID of the Ankle Osteoarthritis Scale and its 2 domains. The distribution-based approaches used were the small and medium effect size methods, while the mean absolute change method and linear regression method were the anchor-based approaches. Bootstrap sampling was used to obtain the variance of MID estimates. The MID was estimated for sex, age, operative, and baseline health subgroups. The cohort comprised 283 participants, totaling 298 ankles.
The MID did not vary with sex or operative procedure. Age-based differences in MID values may exist for the Ankle Osteoarthritis Scale total score, and MID values were generally smallest among the oldest patients. Patients with the best and worst ankle-related health preoperatively had higher MID values than patients reporting mid-range Ankle Osteoarthritis Scale values preoperatively.
The best estimate of the MID of the Ankle Osteoarthritis Scale total score is 5.81. Our findings indicate that the MID of the Ankle Osteoarthritis Scale may not vary by sex or operative subgroups but likely varies by age and preoperative Ankle Osteoarthritis Scale score.
Level II, prospective comparative study.
当保守治疗失败时，踝关节置换和踝关节融合术是治疗终末期踝关节关节炎的标准治疗方法。将患者报告的结果评分与工具的最小重要差异（MID）进行比较，有助于医生和研究人员推断从患者角度来看，治疗后健康状况是否发生了有意义的变化。本研究的目的是估计接受踝关节置换或融合术的终末期踝关节关节炎患者队列中踝关节骨关节炎量表的 MID。
参与者在术前和术后 2 年完成了包括踝关节骨关节炎量表在内的调查包。使用分布和基于锚定的方法来计算 MID，以估计踝关节骨关节炎量表及其 2 个域的 MID。基于分布的方法使用小和中效应量方法，而基于锚定的方法使用平均绝对变化方法和线性回归方法。使用自举抽样获得 MID 估计值的方差。对性别、年龄、手术和基线健康亚组估计 MID。该队列包括 283 名参与者，共计 298 个踝关节。
MID 与性别或手术程序无关。MID 值可能因年龄而异，踝关节骨关节炎量表总分的 MID 值最小，而年龄最大的患者的 MID 值最小。术前踝关节相关健康状况最佳和最差的患者比术前报告踝关节骨关节炎量表值中等范围的患者具有更高的 MID 值。
踝关节骨关节炎量表总分的 MID 最佳估计值为 5.81。我们的研究结果表明，踝关节骨关节炎量表的 MID 可能不受性别或手术亚组的影响，但可能受年龄和术前踝关节骨关节炎量表评分的影响。
II 级，前瞻性比较研究。
