Real-time measurement of post-stroke fatigue in daily life and its relationship with the retrospective Fatigue Severity Scale

Improving our understanding of post-stroke fatigue is crucial to develop more effective interventions. This effort may be hampered by the methods used to assess fatigue, which usually rely on retrospective memory reports. However, such reports are prone to memory bias and may not capture variability in fatigue in daily life; thereby failing to adequately represent symptom experience. This study aimed to assess the strength of the relationship between real-time experience of post-stroke fatigue and the commonly used retrospective Fatigue Severity Scale (FSS). Thirty individuals with stroke completed 10 daily questionnaires about momentary (here-and-now) fatigue for six consecutive days using the mHealth application PsyMateTM (Experience Sampling Method). From these real-time fatigue ratings (N = 1012), we calculated three indices: total average, peak fatigue, and fatigue on the final day. Afterwards, participants rated their fatigue retrospectively with the FSS. Results showed weak to moderate and strong correlations (range: .334, .667), with retrospective reports capturing up to 44% of the variance in the indices of momentary fatigue. Exploratory analyses also revealed that even individuals with similar total FSS scores demonstrated highly different day-to-day fatigue patterns. We conclude that retrospective measures may provide an incomplete view of post-stroke fatigue and diurnal variation therein.

加深对脑卒中后疲劳的认知，对于开发更高效的临床干预手段至关重要。然而，当前相关研究可能受限于现有疲劳评估方法——这类方法通常依赖回顾性记忆报告。此类报告易受记忆偏差影响，且无法捕捉日常生活中疲劳的动态波动，因此难以充分反映患者的真实症状体验。本研究旨在探究脑卒中后疲劳的实时体验与临床常用的回顾性疲劳严重度量表（Fatigue Severity Scale, FSS）之间的关联强度。研究招募30名脑卒中患者，通过移动健康（mHealth）应用PsyMate™采用经验取样法（Experience Sampling Method, ESM），让患者连续6天每日完成10份关于即刻（当下）疲劳状态的问卷。基于收集到的1012条实时疲劳评分数据，我们计算得到三项指标：整体平均疲劳值、峰值疲劳值以及最后一日的疲劳值。随后，受试者采用FSS完成疲劳的回顾性评分。研究结果显示，两者间存在弱至中等乃至较强的相关性（相关系数范围为0.334至0.667），回顾性报告最多可解释即刻疲劳指标中44%的变异量。探索性分析还发现，即便总FSS评分相近的受试者，其每日疲劳模式也存在显著差异。综上，回顾性评估手段对脑卒中后疲劳及其日间波动的刻画可能并不全面。