Psychometric Properties of the German Translation of the QOLIE-31 Theodor W. May,* ,1 Margarete Pfa ¨fflin,* ,† and Joyce A. Cramer ‡ *Gesellschaft fu ¨ r Epilepsieforschung, Bielefeld, Germany; † Epilepsy Center Bethel, Bielefeld, Germany; and ‡ Yale University School of Medicine, New Haven, Connecticut Received January 3, 2001; accepted for publication February 27, 2001 The purpose of this work was to assess the psychometric properties of the German Translation of the Quality of Life in Epilepsy Inventory, QOLIE-31. Internal consistency, construct and criterion validity, and responsiveness were tested in 509 patients with epilepsy who were administered the question- naires at application or at admittance to the epilepsy center Bethel. Construct validity was tested in patients with different seizure frequencies and different degrees of tolerability of antiepileptic drug (AED) therapy (adverse effects). The scales Epilepsy-Related Fears und Restrictions in Daily Life due to Epilepsy were used as criterion measures. Test–retest reliability (long-term stability) and respon- siveness of the questionnaire were analyzed in subgroups of patients who responded to the ques- tionnaires a second time ( n  256). Cronbach’s  of the QOLIE-31 was 0.94 and varied between 0.76 and 0.90 for the seven subscales. The correlations of the QOLIE with Epilepsy-Related Fears and Restrictions in Daily Life revealed high correlations between Epilepsy-Related Fears and the QOLIE subscale Seizure Worry ( r  0.81, P < 0.01) and the total score (r  0.62, P < 0.01) and between Restrictions in Daily Life and the QOLIE subscale Social Functioning (r  0.71) and the total score (r  0.70, P < 0.01). Seizure frequency had a significant effect especially on the QOLIE subscales Social Functioning, Seizure Worry, and Overall QOL, whereas tolerability of AED therapy affected especially the subscales Medication Effects, Overall QOL, and Energy-Fatigue. The test–retest reliability (intra- class correlation coefficient) was 0.79 for the overall score and varied between 0.59 and 0.78 for the seven subscales. The German Translation of QOLIE-31 is a reliable and valid questionnaire with which to assess QOL in patients with epilepsy and is conceptually similar to the English version. It is a sensitive questionnaire with respect to seizure frequency and tolerability of antiepileptic drug treatment. © 2001 Academic Press Key Words: quality of life; epilepsy; QOLIE-31; epilepsy-related fears; seizure frequency; side effects. 1. INTRODUCTION A variety of epilepsy-specific questionnaires have been developed for the assessment of health-related quality of life (1– 6). Most of the validated and estab- lished questionnaires were developed in the United States or United Kingdom (e.g., Liverpool Assessment Battery, ESI-55, QOLIE-89, QOLIE-31, QOLIE-10, SHE). Translations into other languages exist only for some of these questionnaires. If translations exist, a validation of these questionnaires is necessary to check if psychometric properties are fulfilled and com- parable to those of the original version. The Quality of Life with Epilepsy—31 (QOLIE-31) is the short form of the QOLIE-89 and comprises 31 items. It is an international, widely used, epilepsy- specific questionnaire of quality of life with transla- tions available in Afrikaans, Arabic, Belgian, Danish, Dutch, Finnish, German, French (Canada, France), He- brew, Norwegian, Russian, Spanish (Spain, South America, United States), Swedish, Polish, and English (Australia, United Kingdom, United States). The psy- 1 To whom correspondence should be addressed at Gesellschaft fu ¨ r Epilepsieforschung, Maraweg 13, D-33617 Bielefeld, Germany. Fax: +49 (521) 144-2027. E-mail: may_gfe@t-online.de. Epilepsy & Behavior 2, 106–114 (2001) doi:10.1006/ebeh.2001.0170, available online at http://www.idealibrary.com on 1525-5050/01 $35.00 Copyright © 2001 by Academic Press All rights of reproduction in any form reserved. 106