Abstracts

Rationale: The aim of this study was to validate the newly developed shortened Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55) in a sample of children with drug resistant epilepsy. Methods: Data came from the Impact of Pediatric Epilepsy Surgery on Health-Related Quality of Life Study (PEPSQOL), a multicenter prospective cohort study. Participants were recruited during the period of evaluation of candidacy for epilepsy surgery from eight centres across Canada who treat children with drug resistant epilepsy. Health-related quality of life was assessed using the original QOLCE, a 76-item parent-rated epilepsy-specific instrument, and the KIDSCREEN-27, a dual child- and parent-rated generic instrument. Confirmatory factor analysis was used to assess the higher-order factor structure of the QOLCE-55. Internal consistency reliability was evaluated for the original QOLCE and the QOLCE-55 using Cronbach's alpha and the Spearman-Brown prophecy formula. Convergent and divergent validity were assessed by correlating subscales of the KIDSCREEN-27 (parent report) with the QOLCE-55. Results: 136 children (80 males), mean age 11.6 years (range: 4.0-18.6 years; SD = 4.0 years), were recruited. The higher-order factor structure of the QOLCE-55 demonstrated adequate fit: Comparative Fit Index = 0.948; Tucker-Lewis Index = 0.946; Root Mean Square of Approximation = 0.060 (90% CI 0.054?"0.065); Weighted Root Mean Square Residuals = 1.247. As shown in Figure 1, higher-order factor loadings were strong, ranging from ? = 0.74 to 0.81. Internal consistency reliability was excellent (a = 0.97, subscales a > 0.82), showing improvement over the original QOLCE. QOLCE-55 subscale scores demonstrated moderate to strong correlations with similar subscales of the KIDSCREEN-27 (? = .43-.75) and weak to moderate correlations with dissimilar subscales (? = .25-.42). Conclusions: The findings provide support for the factor structure of the QOLCE-55 and contribute to its robust psychometric profile as a reliable and valid instrument. Researchers and health practitioners should consider the QOLCE-55 a viable option to reduce respondent burden when assessing health-related quality of life in children with epilepsy. Funding: PEPSQOL was funded by a grant from the Canadian Institutes for Health Research (MOP-133708) to Dr. Widjaja and Dr. Smith. Ms. Conway is supported by a doctoral fellowship from the Social Sciences and Humanities Research Council.