Department of Orthopaedic Surgery, Mayo Clinic Arizona, Phoenix, AZ, USA.
Texas Christian University School of Medicine, Fort Worth, TX, USA.
Clin Orthop Relat Res. 2023 Jan 1;481(1):63-80. doi: 10.1097/CORR.0000000000002440. Epub 2022 Oct 5.
Patient-reported outcome measures (PROMs) are frequently used to assess the impact of total knee arthroplasty (TKA) on patients. However, mere statistical comparison of PROMs is not sufficient to assess the value of TKA to the patient, especially given the risk profile of arthroplasty. Evaluation of treatment effect sizes is important to support the use of an intervention; this is often quantified with the minimum clinically important difference (MCID). MCIDs are unique to specific PROMs, as they vary by calculation methodology and study population. Therefore, a systematic review of calculated MCID values, their respective ranges, and assessment of their applications is important to guide and encourage their use as a critical measure of effect size in TKA outcomes research.
QUESTIONS/PURPOSES: In this systematic review of MCID calculations and reporting in primary TKA, we asked: (1) What are the most frequently reported PROM MCIDs and their reported ranges in TKA? (2) What proportion of studies report distribution- versus anchor-based MCID values? (3) What are the most common methods by which these MCID values are derived for anchor-based values? (4) What are the most common derivation methods for distribution-based values? (5) How do the reported medians and corresponding interquartile ranges (IQR) compare between calculation methods for each PROM?
Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted using the PubMed, EMBASE, and MEDLINE databases from inception through March 2022 for TKA articles reporting an MCID value for any PROMs. Two independent reviewers screened articles for eligibility, including any article that calculated new MCID values for PROMs after primary TKA, and extracted these data for analysis. Overall, 576 articles were identified, 38 of which were included in the final analysis. These studies had a total of 710,128 patients with a median age of 67.7 years and median BMI of 30.9 kg/m 2 . Women made up more than 50% of patients in most studies, and the median follow-up period was 17 months (range 0.25 to 72 months). The overall risk of bias was assessed as moderate using the Jadad criteria for one randomized controlled trial (3 of 5 ideal global score) and the modified Methodological Index for Non-randomized Studies criteria for comparative studies (mean 17.2 ± 1.8) and noncomparative studies (mean 9.6 ± 1.3). There were 49 unique PROMs for which 233 MCIDs were reported. Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test given non-normal distribution of values.
The WOMAC Function and Pain subscores were the most frequently reported MCID value, comprising 9% (22 of 233) and 9% (22 of 233), respectively. The composite Oxford Knee Score (OKS) was the next most frequently reported (9% [21 of 233]), followed by the WOMAC composite score (6% [13 of 233]). The median anchor-based values for WOMAC Function and Pain subscores were 23 (IQR 16 to 33) and 25 (IQR 14 to 31), while the median distribution-based values were 11 (IQR 10.8 to 11) and 22 (IQR 17 to 23), respectively. The median anchor-based MCID value for the OKS was 6 (IQR 4 to 7), while the distribution-based value was 7 (IQR 5 to 10). Thirty-nine percent (15 of 38) used an anchor-based method to calculate a new MCID, while 32% (12 of 38) used a distribution-based technique. Twenty-nine percent of studies (11 of 38) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing patient satisfaction, pain relief, or quality of life along a five-point Likert scale was the most commonly used anchor (40% [16 of 40]), followed by a receiver operating characteristic curve estimation (25% [10 of 40]). For studies using distribution-based calculations, all articles used a measure of study population variance in their derivation of the MCID, with the most common method reported as one-half the standard deviation of the difference between preoperative and postoperative PROM scores (45% [14 of 31]). Most reported median MCID values (15 of 19) did not differ by calculation method for each unique PROM (p > 0.05) apart from the WOMAC Function component score and the Knee Injury and Osteoarthritis Outcome Score Pain and Activities of Daily Living subscores.
Despite variability of MCIDs for each PROM, there is consistency in the methodology by which MCID values have been derived in published studies. Additionally, there is a consensus about MCID values regardless of calculation method across most of the PROMs we evaluated.
Given their importance to treatment selection and patient safety, authors and journals should report MCID values with greater consistency. We recommend using a 7-point increase as the MCID for the OKS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculation, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using a 10-point to 15-point increase for the MCID of composite WOMAC, as the median value was 12 (IQR 10 to 17) with no difference between calculation methods. We recommend use of median reported values for WOMAC function and pain subscores: 21 (IQR 15 to 33) and 23 (IQR 13 to 29), respectively.
患者报告的结局测量（PROMs）常用于评估全膝关节置换术（TKA）对患者的影响。然而，仅仅对 PROMs 进行统计学比较不足以评估 TKA 对患者的价值，尤其是考虑到关节置换术的风险状况。评估治疗效果大小很重要，有助于支持干预措施的使用；这通常通过最小临床重要差异（MCID）来量化。MCID 是特定 PROMs 特有的，因为它们因计算方法和研究人群而异。因此，对 MCID 值的计算、各自范围的系统综述以及对其应用的评估非常重要，这有助于指导和鼓励将其作为 TKA 结果研究中效应大小的关键衡量标准。
问题/目的：在这项关于原发性 TKA 中 MCID 计算和报告的系统综述中，我们提出了以下问题：（1）在 TKA 中最常报告的 PROM MCID 及其报告范围是多少？（2）有多少研究报告了分布与基于锚定的 MCID 值？（3）基于锚定的 MCID 值的最常见推导方法是什么？（4）基于分布的 MCID 值的最常见推导方法是什么？（5）对于每个 PROM，报告的中位数和相应的四分位间距（IQR）在计算方法之间如何比较？
根据系统评价和荟萃分析的首选报告项目（PRISMA）指南，通过 PubMed、EMBASE 和 MEDLINE 数据库对截至 2022 年 3 月的 TKA 文章进行了系统综述，这些文章报告了任何 PROM 的 MCID 值。两名独立审查员对文章进行了筛选，包括对原发性 TKA 后计算新的 PROM MCID 值的任何文章，并提取这些数据进行分析。总共确定了 576 篇文章，其中 38 篇被纳入最终分析。这些研究共有 710,128 名患者，平均年龄为 67.7 岁，平均 BMI 为 30.9kg/m 2 。大多数研究中女性占患者的 50%以上，中位随访时间为 17 个月（范围 0.25 至 72 个月）。整体偏倚风险使用随机对照试验的 Jadad 标准评估为中度（理想全球评分 3 分中的 3 分）和非随机研究的改良方法学指数（平均 17.2±1.8）和非比较性研究（平均 9.6±1.3）。有 49 种独特的 PROM 用于报告 233 个 MCID。计算值分为基于锚定、基于分布和未报告。从每项研究中提取每个 PROM 的 MCID 值、MCID 计算方法、患者数量和研究人口统计学数据。对于每个独特的 PROM，使用 Wilcoxon 秩和检验比较基于锚定和基于分布的 MCID 值，因为值的分布是非正态的。
WOMAC 功能和疼痛子量表的 MCID 值最常被报告，分别占 9%（22/233）和 9%（22/233）。牛津膝关节评分（OKS）是下一个最常报告的（9%[21/233]），其次是 WOMAC 综合评分（6%[13/233]）。WOMAC 功能和疼痛子量表的中位基于锚定的 MCID 值分别为 23（IQR 16 至 33）和 25（IQR 14 至 31），而基于分布的 MCID 值分别为 11（IQR 10.8 至 11）和 22（IQR 17 至 23）。OKS 的中位基于锚定的 MCID 值为 6（IQR 4 至 7），而分布的 MCID 值为 7（IQR 5 至 10）。39%（15/38）使用基于锚定的方法计算新的 MCID，32%（12/38）使用基于分布的技术。29%的研究（11/38）同时使用了两种方法计算 MCID 值。对于报告基于锚定的计算方法的研究，评估患者满意度、疼痛缓解或生活质量的五分制 Likert 量表问题是最常用的锚定（40%[16/40]），其次是接收者操作特征曲线估计（25%[10/40]）。对于使用分布的计算方法的研究，所有文章都在 MCID 的推导中使用了研究人群方差的测量，最常用的方法是术前和术后 PROM 评分差异的标准差的一半（45%[14/31]）。大多数报告的中位数 MCID 值（15 个中的 19 个）在每种独特的 PROM 中，除了 WOMAC 功能分量评分和膝关节损伤和骨关节炎结果评分疼痛和日常生活活动分量评分外，没有因计算方法的不同而不同（p>0.05）。
尽管每个 PROM 的 MCID 值存在差异，但已发表的研究中 MCID 值的推导方法具有一致性。此外，我们评估的大多数 PROM 中，基于锚定和基于分布的 MCID 值之间存在一致性。
鉴于 MCID 对治疗选择和患者安全的重要性，作者和期刊应该更加一致地报告 MCID 值。我们建议将 OKS 的 7 点增加作为 MCID 值，这与几项使用基于锚定的方法计算 MCID 值的高质量研究中报告的基于锚定的 MCID 值的中位数一致，我们认为这些研究最适合大多数临床研究中的应用。同样，我们建议使用 WOMAC 综合评分的 10 点至 15 点增加作为 MCID，因为中位数为 12（IQR 10 至 17），并且没有因计算方法的不同而不同。我们建议使用报告的中位数值用于 WOMAC 功能和疼痛分量评分：21（IQR 15 至 33）和 23（IQR 13 至 29）。
