Copay Anne G, Eyberg Blake, Chung Andrew S, Zurcher Kenneth S, Chutkan Norman, Spangehl Mark J
SPIRITT Research, St. Louis, Missouri.
Orthopaedic Surgery Residency (B.E. and N.C.) and Phoenix Integrated Surgical Residency (K.S.Z.), University of Arizona College of Medicine, Phoenix, Arizona.
JBJS Rev. 2018 Sep;6(9):e2. doi: 10.2106/JBJS.RVW.17.00160.
The minimum clinically important difference (MCID) attempts to define the patient's experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of the MCID calculation, so as to help practitioners to understand and utilize the MCID and to guide future efforts to calculate the MCID. In Part I of this review, we sampled the orthopaedic literature in relation to the upper extremity. In this part, Part II, of the review, we will focus on the lower-extremity literature.
A review was conducted of the 2014 to 2016 MCID-related publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery. Only clinical science articles utilizing patient-reported outcome measures (PROMs) were included in the analysis. A keyword search was then performed to identify articles that used the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. The MCID utilization in the selected articles was characterized and was recorded.
The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 79 (61.2%) of the 129 articles were related to the lower extremity; of these, 11 (13.9%) independently calculated the MCID values and 68 (86.1%) used previously published MCID values as a gauge of their own results. The MCID values were calculated or were considered for 31 PROMs, of which 24 were specific to the lower extremity. Eleven different methods were used to calculate the MCID. The MCID had a wide range of values for the same questionnaires, for instance, 5.8 to 31.3 points for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
There are more than twice as many PROMs for the lower extremity (24) than for the upper extremity (11), confirming that the determination of useful MCID values is, in part, hampered by the proliferation of PROMs in the field of orthopaedics. The difference between significance and clinical importance needs to be further clarified. For instance, the common use of determining sample size with the MCID and comparing group means with the MCID implies that a significant result will also be clinically important. Further, the study of the MCID would benefit from consensus agreement on relevant terminology and the appropriate usage of the MCID determining equations.
MCID is increasingly used as a measure of patients' improvement. However, MCID does not yet adequately capture the clinical importance of patients' improvement.
最小临床重要差异（MCID）旨在界定患者对治疗结果的体验。计算MCID的努力产生了多个不一致的MCID值。本综述的目的是描述MCID在最新骨科文献中的应用，解释其当前应用的局限性，并阐明MCID计算的基础，以帮助从业者理解和利用MCID，并指导未来计算MCID的工作。在本综述的第一部分，我们抽样了与上肢相关的骨科文献。在本综述的第二部分，我们将关注下肢文献。
对《关节置换术杂志》《骨与关节外科杂志》《美国运动医学杂志》《足与踝关节国际杂志》《骨科创伤杂志》《小儿骨科杂志》以及《肩肘外科杂志》2014年至2016年与MCID相关的出版物进行了综述。分析仅纳入使用患者报告结局测量（PROMs）的临床科学文章。然后进行关键词搜索以识别使用MCID的文章。文章随后进一步分为上肢和下肢出版物。对所选文章中MCID的应用进行了描述并记录。
在1709篇使用PROMs的临床科学文章中，有129篇（7.5%）引用了MCID：129篇文章中有79篇（61.2%）与下肢相关；其中，11篇（13.9%）独立计算了MCID值，68篇（86.1%）使用先前发表的MCID值作为其自身结果的衡量标准。对31种PROMs计算了或考虑了MCID值，其中24种特定于下肢。使用了11种不同的方法来计算MCID。对于相同的问卷，MCID值范围很广，例如，西安大略和麦克马斯特大学骨关节炎指数（WOMAC）为5.8至31.3分。
下肢的PROMs（24种）比上肢（11种）多两倍以上，这证实了在骨科领域PROMs的激增在一定程度上阻碍了有用MCID值的确定。显著性和临床重要性之间的差异需要进一步阐明。例如，常用MCID确定样本量并将组均值与MCID进行比较意味着显著结果在临床上也将是重要的。此外，对MCID的研究将受益于就相关术语和MCID确定方程的适当用法达成共识。
MCID越来越多地被用作衡量患者改善情况的指标。然而，MCID尚未充分体现患者改善的临床重要性。
