Introduction and objectives: Epilepsy is a common chronic disease at all ages and in both sex. Quality of life in epileptic patients is of utmost importance. This study investigated the reliability and validity of the Iranian version of Quality of Life in Epilepsy Inventory-31 (QOLIE-31-P).
Research method: The English version was translated into Persian and then it pilot tested. The instrument includes 31 items in 7 domains including: seizure worry, emotional well-being, energy/fatigue, cognitive functioning, medication effects, social functioning and overall quality of life. The scores range from 0-100 with higher score indicating better conditions. The final version of the Persian questionnaire was administered to a sample of epileptic patients 18years old and over referred to the electroencephalography ward in Sina hospital (Tehran University of Medical Sciences) during 6 months. Reliability was estimated using internal consistency (Cronbach's ?) and validity was assessed using known group comparisons.
Results: In all 76 patients were studied. The mean age of the patients was 30.6 years (SD=12.2) and the mean years of their education was 9.9 (SD=4.2). The analysis showed that the domains met the minimum reliability standard, Cronbach's ? coefficient ranging from 0.71-0.89 with the exception of medication effects and social functioning (a= 0.51 & 0.65). Validity analysis showed that the instrument discriminated well between subgroups of patients that differed in "seizure types, frequency of epileptic attacks in previous month and year". Patients with partial seizure and who experienced higher attacks in preceding month or year, showed lower scores in all scales.
Conclusion: The Iranian version of the QOLIE-31-P is a reliable and valid measure of health-related quality of life in patients with epilepsy.