Content validity and psychometric evaluation of the Functional Assessment of Chronic Illness Therapy-Fatigue scale in patients with chronic lymphocytic leukemia

Journal of Patient-Reported Outcomes

Daniel Eek¹  Cristina Ivanescu²  Laura Corredoira³  Oren Meyers⁴  David Cella⁵ 

[1] AstraZeneca Gothenburg, Pepparedsleden 1, 431 50, Mölndal, Sweden;IQVIA, Amsterdam, The Netherlands;IQVIA, Barcelona, Spain;IQVIA, New York, NY, USA;Northwestern University, Evanston, IL, USA;

关键词: Chronic lymphocytic leukemia;    Content validity;    FACIT-Fatigue;    Psychometric properties;   

DOI  :  10.1186/s41687-021-00294-1

来源: Springer

【 摘 要 】

PurposeFatigue 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.MethodsThe 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).ResultsInterviewed 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.ConclusionsContent validity and psychometric evaluation in patients with CLL demonstrated that the FACIT-Fatigue has good psychometric properties and is fit for purpose in CLL.

【 授权许可】

CC BY