Arch Hellen Med, 37(2), March-April 2019, 245-253
Reliability and validity of the Greek version of the Multidimensional Fatigue Inventory (MFI-20)
CE. Aslani,1,2 P. Andriopoulos,2 A. Kattamis,3 G. Lyrakos,1,2,4 M. Tsironi2
OBJECTIVE To evaluate the reliability and validity of the Multidimensional Fatigue Inventory (MFI-20) in Greek patients with hemoglobinopathies, and to assess the value of the psychometric properties of the MFI-20 as a complementary diagnostic tool in thalassemia fatigue.
METHOD The psychometric properties of the instrument that were evaluated included internal consistency and construct validity. The study sample consisted of two diagnostic groups of individuals with hemoglobinopathies: patients reporting fatigue (219) and patients with no fatigue (63). The participants all provided written informed consent, and completed a series of questionnaires: the MFI-20, the EuroQoL (EQ-5D) thermometer, covering present health, and the Depression Anxiety Stress Scale with 21 items (DASS21). The five MFI-20 subscales were assessed using inter-item correlation, corrected item-total correlation, internal consistency reliability (Cronbach's alpha coefficients), construct validity, discriminant (known-group) validity, and convergent validity through correlation with the EQ 5D and DASS21 instruments.
RESULTS Averaged inter-item correlations ranged from 0.25 to 0.53, indicating no item redundancy. Corrected item-total correlations for all MFI-20 subscales were greater than 0.30, and Cronbach's alpha coefficients achieved an acceptable level of 0.70, with the exception of Physical Fatigue (α=0.676). Factor analysis demonstrated factorial complexity. The MFI-20 also distinguished clearly between the two diagnostic groups on general fatigue and physical fatigue. Furthermore, correlations with depression and anxiety (DASS21), and present health demonstrated good convergent validity.
CONCLUSIONS This study provides support for use of the MFI-20 as a valuable tool for assessing fatigue in populations with hemoglobinopathy.
Key words: Fatigue, Fatigue dimensions, Hemoglobinopathies, MFI-20, Validation.