Validity and Reliability of the Quality of Life in Epilepsy Inventory (QOLIE-31) for Turkey.

INTRODUCTION The purpose of this study was to evaluate reliability and validity of the 31-item Quality of Life in Epilepsy Inventory (QOLIE-31) in Turkish epileptic patients. METHODS This study was performed methodologically. To standardize the inventory, using a standard "forward-backward" translation and cultural adaptation procedure the English version of the QOLIE-31 was translated to Turkish. Language equivalence of the scale was provided. The opinions of experts were considered regarding the content validity of the scale. Reliability of the scale was determined with the test-retest reliability, item-total correlation and internal consistency analysis. For the construct validity, QOLIE-31 was compared with Nottingham Health Profile (NHP) scale and pre validity was determined. RESULTS One hundred and forty-eight epileptic patients (62 females, 86 males), with a mean age of 32.5 (SD: 10.71) years were enrolled in the study. Content Validity Index of instrument was .85. Alpha reliability was .91. Item-total correlations were between .46 and .74 (p=.001). The mean score for the quality of life of epileptic patients was found to be moderate level (56.4; SD: 17.3). The mean score of Seizure Worry subscale was the lowest (48.9, SD: 29.82), while social function subscale (60.1, SD: 20.12) was found to be highest. As expected, correlations between QOLIE-31 and NHP subscales were fairly strong, particularly between those subscales with close or interdependent content. Thus, Emotional Well-Being correlated with NHP Emotional Reactions, Social Isolation and Pain; Social Function with NHP Social Isolation and Physical Mobility; Seizure Worry with NHP Social Isolation and Emotional Reactions; and Cognitive Function with NHP Energy, Emotional Reactions and Pain. CONCLUSION The Turkish version of the QOLIE-31 questionnaire has good structural characteristics, is a reliable and valid instrument and can be used for measuring the effect of epilepsy on the quality of life.