Background and Purpose

The modified Rankin Scale (mRS) is the most widely used primary outcome measure in acute stroke trials. However, substantial interobserver variability impairs outcome assessment as well as reduces power of clinical trials. Guided by the International Classification of Functioning, Disability and Health, we developed a comprehensive, hierarchical assessment tool (miFUNCTION) to address the shortcomings of the modified Rankin Scale and deliver a more thorough understanding of disability following stroke.

Methods

The initial construct validity of miFUNCTION was established in a pilot study of patients at an outpatient stroke prevention clinic that had been diagnosed with stroke within 60 days. To further assess criterion validity, miFUNCTION was compared against the modified Rankin Scale and other outcome measures within the Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE) trial. Logistic regression analysis with miFUNCTION as an outcome was used to demonstrate the beneficial effect of endovascular treatment.

Results

The pilot study showed moderate inter-observer agreement (k = 0.585, p < 0.005) but near perfect correlation between miFUNCTION and modified Rankin Scale (ρ = 0.821, p < 0.05). The correlation of miFUNCTION and modified Rankin Scale was near perfect again in the ESCAPE trial (ρ = 0.944). Effect size of the multivariable models using modified Rankin Scale (adjusted odds ratio: 3.45, 95% confidence interval: 2.05–5.78) and miFUNCTION (adjusted odds ratio: 3.32, 95% confidence interval: 1.99–5.55) as an outcome measure for the ESCAPE trial patients was similar.

Conclusions

miFUNCTION is strongly associated with the degree of disability following stroke both in an outpatient setting and a clinical trial. Further work remains to assess sensitivity to change and to improve the inter-observer reliability of the scale.

中文翻译：

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使用新开发的miFUNCTION量表对中风后残疾进行综合评估

背景和目的

改良的Rankin量表（mRS）是急性卒中试验中使用最广泛的主要结局指标。但是，观察者之间的巨大差异会损害结果评估并降低临床试验的效力。在《国际功能，残疾与健康分类》的指导下，我们开发了一种全面的分级评估工具（miFUNCTION），以解决改良的Rankin量表的不足，并更全面地了解卒中后的残疾。

方法

miFUNCTION的初始构建体有效性是在门诊中风预防诊所对患者进行的一项初步研究中确定的，该患者已在60天内被诊断出患有中风。为了进一步评估标准的有效性，将miFUNCTION与改良的Rankin量表和其他针对小核心和前循环近端闭塞的血管内治疗中的其他结局指标进行了比较，重点是将CT缩短至再通时间（ESCAPE）。以miFUNCTION作为结果的Logistic回归分析用于证明血管内治疗的有益效果。

结果

初步研究显示，观察者之间的同意程度中等（k = 0.585，p <0.005），但miFUNCTION与改良的Rankin量表之间具有近乎完美的相关性（ρ= 0.821，p <0.05）。在ESCAPE试验中，miFUNCTION与改良的Rankin量表的相关性再次接近完美（ρ= 0.944）。使用修正的Rankin量表（调整后的优势比：3.45，95％置信区间：2.05–5.78）和miFUNCTION（调整后的优势比：3.32，95％置信区间：1.99–5.55）作为变量的多变量模型的效应量。 ESCAPE试验患者相似。

结论

在门诊和临床试验中，miFUNCTION与卒中后的残疾程度密切相关。还需要进一步的工作来评估对变化的敏感性，并提高秤的观察者间可靠性。