Abstracts

Rationale: The Patient-Weighted Quality of Life in Epilepsy Inventory (QOLIE-31-P) is a pivotal self-reported questionnaire to assess health-related QOL factors of individuals with epilepsy worldwide. It consists of 31 items assessing 7 domains of living with epilepsy: overall QOL, seizure worry, emotional well-being, energy/fatigue, cognitive functioning, medication effects, and social functioning. The scale has been translated into Japanese, yet, only been validated linguistically. The aim of this study is to investigate the psychometric validity and reliability of the Japanese version of the QOLIE-31-P.


Methods: The study included 167 patients with epilepsy (87 women, aged 18-67 years) who underwent comprehensive assessment including long-term video-electroencephalography monitoring, neuroimaging studies, neuropsychological assessment, and psychiatric and psychosocial assessment in our epilepsy monitoring unit. Inclusion criteria for the study were (1) aged 18 years and above, (2) diagnosed with epilepsy, (3) to have the full IQ score of 70 and above in the Wechsler Adult Intelligence Scale, 3rd edition (WAIS-III), and (4) to have consented to participate in the study. Data were obtained from medical records and self-reporting questionnaires. Data analyses were performed using the confirmatory factor analysis (CFA) to evaluate the factorial structure of the QOLIE-31-P, followed by statistical analyses of reliability and validity.


Results: The CFA revealed that 7-factor model had an acceptable fit (Robust CFI = 0.928, Robust TLI = 0.921，Robust RMSEA = 0.088, SRMR = 0.083). We found the QOLIE-31-P to have acceptable internal consistency for the total scores (Cronbach’s a = 0.89) and 7 subscales (Cronbach’s a = 0.67 – 0.87). The convergent validity of the scale was confirmed by adequate correlation with depression as measured by the Neurological Disorders Depression Inventory for Epilepsy (r = -0.68, p < 0.01) and the Medical Outcomes Study Social Support Survey (r = 0.19, p < .05).


Conclusions: The QOLIE-31-P demonstrated acceptable validity and reliability. The present study is the first to confirm the psychometric validity of the Japanese version of the QOLIE-31-P, indicating the acceptable factorial structure, adequate internal consistency, and satisfactory convergent validity. The Japanese version of the QOLIE-31-P would continue to be an essential self-reported questionnaires as a patient-reported outcome for clinical practice and research in epilepsy care.


Funding: This work was funded by Japan Society for the Promotion of Science Grant-in-Aid for Young Scientists (grant number 21K16616); Japan Ministry of Health, Labour and Welfare Health Labour Sciences Research Grant Comprehensive Research on Disability Health and Welfare (grant number 21GC1017, 23GC1010), the General Insurance Association of Japan Research Grant (grant number 23-08).