Inflated Estimates of Proportional Recovery From Stroke: The Dangers of Mathematical Coupling and Compression to Ceiling.
Inflated Estimates of Proportional Recovery From Stroke: The Dangers of Mathematical Coupling and Compression to Ceiling.
复制标题
DOI：
10.1161/strokeaha.120.033031
复制
发表时间：
2021-05
期刊：
影响因子：
8.3
通讯作者：
Price C
中科院分区：
文献类型：
--
作者：
Bowman H;Bonkhoff A;Hope T;Grefkes C;Price C
比例恢复规则规定，大多数幸存者在中风后恢复固定比例(~70%)的丧失功能。初始分数和随后的变化(结果减去初始；即恢复)之间的强烈(负)相关性被解释为对比例恢复规则的经验支持。然而，这一规则最近受到了批评，一个核心观察是，在通常评估初始分数与随时间变化的情况下，初始分数与变化的相关性是混乱的。这一批评促使在两篇著名的论文中重新评估了中风后患者的行为轨迹。其中第一个，由van der Vliet和他的合作者提出了一个令人印象深刻的中风后上肢缺陷的模型，避免了初始分数与变化的混淆关联。昆德特及其合作者的第二项研究重新评估了比例恢复规则的价值，该规则经典地表述为初始分数与变化之间的相关性。他们认为，虽然对个体患者恢复轨迹的有效预测不能得到现有证据的支持，但群体水平上关于比例恢复存在的推断是可靠的。在这篇文章中，我们对范德弗利特和昆德特的论文作出回应，通过提炼争论的本质来解释为什么比例恢复的经典评估是混乱的。在这方面，我们再次强调数学耦合和对上限的压缩在初始分数与变化的相关性的混淆性质中的作用。我们进一步认为，这种混淆将出现在个人水平和群体水平的推理中。然后，我们将重点放在天花板效应可能带来的困难上，即使初始分数与变化/恢复无关。最后，我们强调需要新的技术来分析中风后的恢复，这些技术不会以这里强调的方式混淆。
The proportional recovery rule states that most survivors recover a fixed proportion (~70%) of lost function after stroke. A strong (negative) correlation between the initial score and subsequent change (outcome minus initial; i.e. recovery) is interpreted as empirical support for the proportional recovery rule. However, this rule has recently been critiqued, with a central observation being that the correlation of initial-scores with change over time is confounded in the situations in which it is typically assessed. This critique has prompted reassessments of patients’ behavioural trajectory following stroke in two prominent papers. The first of these, by van der Vliet and collaborators presented an impressive modelling of upper limb deficits following stroke, which avoided the confounded correlation of initial-scores with change. The second by Kundert and collaborators reassessed the value of the proportional recovery rule, as classically formulated as the correlation between initial-scores and change. They argued that, while effective prediction of recovery trajectories of individual patients is not supported by the available evidence, group-level inferences about the existence of proportional recovery are reliable. In this paper, we respond to the van der Vliet and Kundert papers by distilling the essence of the argument for why the classic assessment of proportional recovery is confounded. In this respect, we re-emphasize the role of mathematical coupling and compression to ceiling in the confounded nature of the correlation of initial-scores with change. We further argue that this confound will be present for both individual-level and group-level inference. We then focus on the difficulties that can arise from ceiling effects, even when initial-scores are not being correlated with change/ recovery. We conclude by emphasizing the need for new techniques to analyse recovery after stroke that are not confounded in the ways highlighted here.