Psychometric properties of the Czech version of the Quality of Life in Epilepsy Inventory (QOLIE-31)

Abstract

The aim of this work was to assess the psychometric properties of the Czech version of the Quality of Life in Epilepsy Inventory (QOLIE-31). The study population comprised 221 patients with epilepsy who were administered the questionnaires during their regular visit to the Neurology Clinic of the University Hospital Hradec Kralove. Internal consistency (Cronbach’s α) and validity using factor analysis were tested to detect similarities to and differences from the original version. Validity testing was completed by analysis of variance (ANOVA) of QOLIE-31 scores against seizure frequency. The internal consistency of each subscale of the QOLIE-31 was above the accepted standard of 0.7, except for Overall Quality of Life. Cronbach’s α for the QOLIE-31 was 0.70 and varied between 0.68 and 0.89 for the seven subscales. Factor analysis of the 30 items yielded seven factors. The first factor was more heterogeneous, containing high loadings from four of the five items constituting Emotional Well-Being and three of the four items constituting Energy/Fatigue. Seizure Worry and Medication Effects were confirmed as single factors, whereas the assignment of the items in Social Functioning was not satisfactory. The seventh single factor consisted of the item “driving” from the Social Functioning subscale. Seizure frequency had a significant effect on all QOLIE-31 subscales and Overall score. Except for Social Functioning, the psychometric properties of the Czech version of the QOLIE-31 are good and similar to those of the original English version. The Czech version thus meets established psychometric criteria for validity and reliability.