Department of Rehabilitation Medicine, Center for Brain Plasticity and Recovery, Georgetown University and MedStar National Rehabilitation Hospital, Washington, DC.
Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA.
Arch Phys Med Rehabil. 2021 Feb;102(2):270-279. doi: 10.1016/j.apmr.2020.08.019. Epub 2020 Sep 28.
To determine the extent to which estimates of sample and effect size in stroke rehabilitation trials can be affected by simple summation of ordinal Upper Extremity Fugl-Meyer (UEFM) items compared with a Rasch-rescaled UEFM.
Rasch analysis of Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) phase III trial data, comparing 3 upper extremity (UE) motor treatments in stroke survivors enrolled 45.8±22.4 days poststroke. Participants underwent a structured UE motor training known as the Accelerated Skill Acquisition Program, usual and customary care, or dose-equivalent care. UEFM data from baseline, postintervention, and 6 and 12 months later were included for analysis.
Outpatient stroke rehabilitation.
ICARE participants (N=361).
Not applicable.
Item difficulties, person abilities, and sample size.
Because of their ordinality, summed raw UEFM scores measured motor impairment inconsistently across different ranges of stroke severity relative to the rescaled UEFM. In the full ICARE sample, raw UEFM understated scores relative to the rescaled UEFM by 7.4 points for the most severely impaired, but overstated scores by up to 8.4 points toward the ceiling. As a result, 50.9% of all UEFM observations showed a residual error greater than 10% of the total UEFM score. Relative to the raw scores, the rescaled UEFM improved the effect size of change in motor impairment between baseline and 1 year (d=0.35). For a hypothetical 3-arm trial resembling ICARE, UEFM rescaling reduced the required sample size by 32% (n=108) compared with raw UEFM (n=159).
In UE rehabilitation trials, a rescaled UEFM potentially decreases sample size by one-third, decreasing costs, duration, and the number of subjects exposed to experimental risks. This benefit is obtained through increased measurement efficiency. Reductions in ceiling effects are also possible. These findings apply to ICARE-like trials. Confirmatory validation in another phase III trial is needed.
确定在中风康复试验中，与 Rasch 重标化上肢 Fugl-Meyer（UEFM）相比，通过简单地对有序的上肢 Fugl-Meyer（UEFM）项目进行求和，对样本量和效应量的估计会受到多大程度的影响。
对跨学科综合上肢康复评估（ICARE）三期试验数据进行 Rasch 分析，比较 45.8±22.4 天中风后入组的 3 种上肢（UE）运动治疗。参与者接受了一种称为加速技能获取计划的结构化 UE 运动训练，以及常规护理和等效剂量护理。分析包括基线、干预后以及 6 个月和 12 个月后的 UEFM 数据。
门诊中风康复。
ICARE 参与者（N=361）。
不适用。
项目难度、个体能力和样本量。
由于 UEFM 得分的有序性，与 Rasch 重标化 UEFM 相比，不同严重程度中风患者的原始 UEFM 得分在测量运动障碍时不一致。在完整的 ICARE 样本中，原始 UEFM 相对于 Rasch 重标化 UEFM 低估了最严重受损患者的得分，而在接近上限时高估了高达 8.4 分。结果，50.9%的所有 UEFM 观察结果显示残余误差大于 UEFM 总分的 10%。与原始分数相比，Rasch 重标化改善了运动障碍在基线和 1 年之间的变化的效应量（d=0.35）。对于类似于 ICARE 的假设 3 臂试验，与原始 UEFM（n=159）相比，UEFM 重标化将所需样本量减少了 32%（n=108）。
在 UE 康复试验中，通过提高测量效率，Rasch 重标化 UEFM 可能将样本量减少三分之一，降低成本、试验持续时间和暴露于实验风险的受试者数量。这一益处是通过提高测量效率获得的。还可能降低上限效应。这些发现适用于类似于 ICARE 的试验。需要在另一个三期试验中进行确认性验证。
