Eek Daniel, Ivanescu Cristina, Corredoira Laura, Meyers Oren, Cella David
AstraZeneca Gothenburg, Pepparedsleden 1, 431 50, Mölndal, Sweden.
IQVIA, Amsterdam, The Netherlands.
J Patient Rep Outcomes. 2021 Mar 11;5(1):27. doi: 10.1186/s41687-021-00294-1.
Fatigue is a prominent symptom in individuals with chronic lymphocytic leukemia (CLL). This work evaluates the content validity and psychometric properties of the Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-Fatigue) in patients with CLL to determine if it is fit for purpose in CLL research.
The FACIT-Fatigue yields a 13-item total score from a five-item symptom subscale and an eight-item impact subscale. To evaluate content validity, cognitive debriefing interviews were conducted with 40 patients with CLL in the first-line or relapsed or refractory setting. Psychometric properties, including structural validity, internal consistency, construct and known-groups validity, were investigated using data from a phase 3 trial in relapsed or refractory CLL (NCT02970318).
Interviewed patients considered the FACIT-Fatigue items relevant to their CLL experience, understood the terminology and agreed with response options. Confirmatory factor analysis confirmed the presence of symptom and impact subscales, but also supported unidimensionality of the FACIT-Fatigue. The FACIT-Fatigue total, symptom and impact subscales demonstrated good internal consistency (Cronbach's coefficient α > 0.85 and McDonald's omega ω > 0.90), and strong correlations with relevant EORTC QLQ-C30 scales (all Spearman's r ≥ 0.5). Known-groups validity was shown by significant differences between groups defined by baseline performance status, hemoglobin level and constitutional symptoms (all p < .0001). Cluster analysis supported FACIT-Fatigue score thresholds of 30 and 34 to define a severe fatigue population.
Content validity and psychometric evaluation in patients with CLL demonstrated that the FACIT-Fatigue has good psychometric properties and is fit for purpose in CLL.
疲劳是慢性淋巴细胞白血病（CLL）患者的一个突出症状。本研究评估慢性病治疗功能评估-疲劳量表（FACIT-疲劳量表）在CLL患者中的内容效度和心理测量学特性，以确定其是否适用于CLL研究。
FACIT-疲劳量表通过一个包含5个条目的症状子量表和一个包含8个条目的影响子量表得出13个条目的总分。为评估内容效度，对40例一线、复发或难治性CLL患者进行了认知访谈。使用复发或难治性CLL的3期试验（NCT02970318）数据研究心理测量学特性，包括结构效度、内部一致性、构想效度和已知组效度。
接受访谈的患者认为FACIT-疲劳量表的条目与他们的CLL经历相关，理解术语并同意回答选项。验证性因素分析证实了症状和影响子量表的存在，但也支持FACIT-疲劳量表的单维度性。FACIT-疲劳量表总分、症状和影响子量表显示出良好的内部一致性（克朗巴赫系数α>0.85，麦克唐纳ω系数>0.90），并与相关的欧洲癌症研究与治疗组织QLQ-C30量表有强相关性（所有斯皮尔曼r≥0.5）。基线表现状态、血红蛋白水平和体质症状定义的组间存在显著差异，表明了已知组效度（所有p<0.0001）。聚类分析支持FACIT-疲劳量表得分阈值为30和34来定义严重疲劳人群。
CLL患者的内容效度和心理测量学评估表明，FACIT-疲劳量表具有良好的心理测量学特性，适用于CLL研究。
