Finnish Centre for Evidence-Based Orthopaedics (FICEBO), Department of Orthopaedics and Traumatology, Tampere University Hospital, TAYS Hatanpää, Hatanpäänkatu 24, 33900, Tampere, Finland.
Finnish Centre for Evidence-Based Orthopaedics (FICEBO), Department of Orthopaedics and Traumatology, University of Helsinki and Helsinki University Hospital, Topeliuksenkatu 5, HUS, 00029, Helsinki, Finland.
BMC Med Res Methodol. 2021 Mar 6;21(1):45. doi: 10.1186/s12874-021-01241-w.
The results of clinical trials should be assessed for both statistical significance and importance of observed effects to patients. Minimal important difference (MID) is a threshold denoting a difference that is important to patients. Patient acceptable symptom state (PASS) is a threshold above which patients feel well.
To determine MID and PASS for common outcome instruments in patients with subacromial pain syndrome (SAPS).
We used data from the FIMPACT trial, a randomised controlled trial of treatment for SAPS that included 193 patients. The outcomes were shoulder pain at rest and on arm activity, both measured with the 0-100 mm visual analogue scale (VAS), the Constant-Murley score (CS), and the Simple Shoulder Test (SST). The transition question was a five-point global rating of change. We used three anchor-based methods to determine the MID for improvement: the receiver operating characteristic (ROC) curve, the mean difference of change and the mean change methods. For the PASS, we used the ROC and 75th percentile methods and calculated estimates using two different anchor question thresholds.
Different MID methods yielded different estimates. The ROC method yielded the smallest estimates for MID: 20 mm for shoulder pain on arm activity, 10 points for CS and 1.5 points for SST, with good to excellent discrimination (areas under curve (AUCs) from 0.86 to 0.94). We could not establish a reliable MID for pain at rest. The PASS estimates were consistent between methods. The ROC method PASS thresholds using a conservative anchor question threshold were 2 mm for pain at rest, 9 mm for pain on activity, 80 points for CS and 11 points for SST, with AUCs from 0.74 to 0.83.
We recommend the smallest estimate from different methods as the MID, because it is very unlikely that changes smaller than the smallest MID estimate are important to patients: 20 mm for pain VAS on arm activity, 10 points for CS and 1.5 points for SST. We recommend PASS estimates of 9 mm for pain on arm activity, 80 points for CS, and 11 points for SST.
ClinicalTrials.gov NCT00428870 (first registered January 29, 2007).
临床试验的结果应评估统计学意义和观察到的对患者的影响的重要性。最小有意义差异（MID）是表示对患者重要的差异的阈值。患者可接受的症状状态（PASS）是患者感觉良好的阈值。
确定肩峰下疼痛综合征（SAPS）患者常见结局工具的 MID 和 PASS。
我们使用了 FIMPACT 试验的数据，这是一项 SAPS 治疗的随机对照试验，共纳入了 193 名患者。结果包括静息时和活动时的肩部疼痛，均采用 0-100mm 视觉模拟量表（VAS）、Constant-Murley 评分（CS）和简单肩部测试（SST）进行测量。转移问题是一个五分制的变化总体评价。我们使用三种基于锚定的方法来确定改善的 MID：接收器工作特征（ROC）曲线、变化的均值差和均值变化方法。对于 PASS，我们使用了 ROC 和第 75 百分位数方法，并使用两个不同的锚定问题阈值计算了估计值。
不同的 MID 方法得出了不同的估计值。ROC 方法得出的 MID 估计值最小：活动时肩部疼痛为 20mm，CS 为 10 分，SST 为 1.5 分，具有良好到优秀的区分度（曲线下面积（AUCs）为 0.86 至 0.94）。我们无法确定静息时疼痛的可靠 MID。PASS 估计值在不同方法之间是一致的。使用保守的锚定问题阈值的 ROC 方法 PASS 阈值为静息时疼痛 2mm，活动时疼痛 9mm，CS 80 分，SST 11 分，AUCs 为 0.74 至 0.83。
我们建议使用不同方法中的最小估计值作为 MID，因为变化小于最小 MID 估计值对患者来说不太可能是重要的：活动时肩部疼痛 VAS 为 20mm，CS 为 10 分，SST 为 1.5 分。我们建议 PASS 估计值为活动时疼痛 9mm，CS 为 80 分，SST 为 11 分。
ClinicalTrials.gov NCT00428870（首次注册于 2007 年 1 月 29 日）。
