The Greek version of the quality of life in epilepsy inventory (QOLIE-31)

This study is presenting the translation and cultural adaptation into Greek of the Quality of Life in Epilepsy Inventory (QOLIE-31). We adapted the QOLIE-31 to Greek through a procedure of translation-back-translation. Sixty-three patients were interviewed and completed the QOLIE-31 and the GHQ questionnaires. We re-examined a subset of them after a period of 2-5 weeks to evaluate the test-retest reliability of the questionnaire. We assessed the convergent validity by comparison of the QOLIE-31 and the GHQ and QOLIE-31 subscales and external measures. Discriminative validity was evaluated using the method of known-groups comparisons. The internal consistency was high for the QOLIE-31 and its' subscales (Cronbach's alpha 0.92 and 0.59-0.83 respectively). Test-retest reliability was acceptable (intra-class correlation coefficient 0.49-0.89 and Pearson's coefficient 0.53-0.92) for the group of patients who were re-examined. Comparison of the QOLIE-31 and GHQ scores showed agreement between the two questionnaires (Pearson's coefficient -0.61). We demonstrated the discriminative validity by the difference in the QOLIE-31 scores between patients with different seizure frequencies and different employment status. We concluded that the Greek version of the QOLIE-31 has psychometric properties equivalent to those of the original American-English version and is a valid and reliable instrument.