The validity of EORTC QLQ-C30 fatigue scale in advanced cancer patients and cancer survivors

Abstract

Fatigue is a major complaint among advanced cancer patients. Several instruments are available for measuring fatigue. The EORTC QLQ-C30 is one of the most frequently used health-related quality of life (HRQOL) instruments, and it includes a three-item fatigue subscale. Limited knowledge exists about the validity, performance and sensitivity of EORTC QLQ-C30 fatigue scale as compared with a fatigue-specific instrument. The aim of the present study was to validate the EORTC QLQ-C30 fatigue scale (FA) against the Fatigue Questionnaire (FQ). The FQ is frequently used and was developed to measure fatigue in both cancer and noncancer populations. The FQ measures physical (PF, seven items) and mental fatigue (MF, four items). The study population included two different cohorts: A) patients with advanced metastatic cancer included in a prospective randomized study of palliative radiotherapy ( n = 238); B) patients with leukaemia and malignant lymphoma curatively treated with stem-cell transplantation and high-dose chemotherapy ( n = 128). The analysis demonstrated that the FA correlated higher with the PF scale (r = 0.67–0.75) as compared with the MF scale (r = 0.49–0.61). The item–scale correlations between FA items and the PF scale were consistently higher than between FA items and the MF scale. A factor analysis including all the items within the FA and the FQ identified two factors. All FA items loaded on a PF factor (0.70–0.85). A floor/ ceiling effect, indicating a high number of respondents with lowest, respectively, highest scores was observed more frequently in the FA as compared with the FQ. The PF discriminated better between diagnostic groups with different levels of fatigue than the FA did. In conclusion, the EORTC QLQ-C30 fatigue scale is measuring physical fatigue. A floor/ ceiling effect seems to appear for the EORTC QLQ-C30 fatigue scale. The validity of the EORTC QLQ-C30 fatigue scale is to be questioned for use in palliative care patients. In studies with fatigue as a defined end point, a domain-specific instrument should, therefore, be added.

Cancer‐related fatigue measures in palliative care: A psychometric systematic review

“…The structural validity was rated as ‘inadequate’ or ‘doubtful’ in three of the 10 instruments: European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire (Knobel et al, 2003; Mystakidou et al, 2001), Cancer Fatigue Scale (Okuyama et al, 2000) and Brief Fatigue Index (Mystakidou et al, 2008; Okuyama et al, 2003). Consequently, in most cases, the size of the sample included in the analysis was not adequate or, to a lesser extent, the choice of model did not fit the research question well and/or there were other major flaws in the design or statistical methods of the study.…”

“…The test–retest reliability was measured for a single study, and this score classified as ‘inadequate’, resulting ICC value >0.70 (except for the subscales of symptoms: nausea/vomiting, where ICC = 0.63) (Godoy Fernández et al, 1999). The hypotheses testing was ‘adequate’ or ‘very good’ in all studies with significant correlations with different scales (Table 3) (Godoy Fernández et al, 1999; Kaasa et al, 1995; Knobel et al, 2003; Mystakidou et al, 2001; Nicklasson & Bergman, 2007).…”

“…This instrument was included in five studies (Godoy Fernández et al, 1999; Kaasa et al, 1995; Knobel et al, 2003; Mystakidou et al, 2001; Nicklasson & Bergman, 2007), and many of the psychometric properties were evaluated, except for content validity, measurement error and criterion validity. Structural validity obtained a rating of ‘doubtful’ or ‘adequate’ for the two studies where it was evaluated (Knobel et al, 2003; Mystakidou et al, 2001) with a structure of six factors (Mystakidou et al, 2001) and a structure of two factors (Knobel et al, 2003).…”

“…This instrument was included in five studies (Godoy Fernández et al, 1999; Kaasa et al, 1995; Knobel et al, 2003; Mystakidou et al, 2001; Nicklasson & Bergman, 2007), and many of the psychometric properties were evaluated, except for content validity, measurement error and criterion validity. Structural validity obtained a rating of ‘doubtful’ or ‘adequate’ for the two studies where it was evaluated (Knobel et al, 2003; Mystakidou et al, 2001) with a structure of six factors (Mystakidou et al, 2001) and a structure of two factors (Knobel et al, 2003). For internal consistency, the rating was ‘very good’, and the result was a Cronbach's alpha >0.70 for all the studies where this property was evaluated (Godoy Fernández et al, 1999; Kaasa et al, 1995; Mystakidou et al, 2001; Nicklasson & Bergman, 2007) but with exceptions, as a Cronbach's alpha of ˂0.70 was obtained in the functioning scales (role and cognitive) (Kaasa et al, 1995), in the emotional function and cognitive function subscales (Godoy Fernández et al, 1999), the physical functioning and fatigue symptom scales, nausea/vomiting and pain (Mystakidou et al, 2001) and the cognitive functioning scale (Nicklasson & Bergman, 2007).…”

Mental Load and Fatigue Assessment Instruments: A Systematic Review

“…These athletes felt slower, with poor reaction times and decreased accuracy. Moreover, a great number of papers have demonstrated the relationship between an increase in the feelings of mental fatigue and a decrease in the specific behavioral performance in different areas [ 34 , 52 , 67 ]. On the contrary, the results of the present study suggest that few instruments have been validated for this purpose from a behavioral perspective.…”