Abstracts

Rationale: Although seizure severity and frequency are important components of the overall severity of epilepsy, they do not provide a complete clinical representation of the severity of a child’s epilepsy as a potential determinant of HRQL. One objective of the Health-related Quality of Life in Childhood Epilepsy Study (HERQULES) is to prospectively assess the determinants of HRQL in children aged 4-12 years during the first two years post diagnosis. Here we report the association between neurologists’ ratings of the overall severity of epilepsy and parent-reported HRQL in children. Methods: HERQULES recruited parents of children ages 4-12 newly diagnosed with epilepsy through 52 pediatric neurologists across Canada. Parents completed mailed surveys that collected various information, including child’s HRQL, four times: post-diagnosis (T1), at 6 months (T2), 12 months (T3) and 24 months (T4). The neurologists provide clinical information at the same timesincluding the Global Assessment of Severity of Epilepsy (GASE) Scale, a single-item, 7-point global rating scale we designed for neurologists to assess overall severity of epilepsy in children. HRQL was assessed using the Quality of Life in Children with Epilepsy Questionnaire (QOLCE, producing a total score ranging from 0 (low functioning) to 100 (high functioning). The association between the GASE scale and the total QOLCE score at each of the completed three times (T1-T3) is quantified using the Spearman rank-order correlation coefficient. Results: Response rate for parents at T1 was 82% and attrition remains low (10%) at the completion of T3. The sample of 376 children aged 4-12 years (mean=7.5 years; SD=2.3), of which 52% are boys, is clinically diverse with 38% experiencing generalized and 62% partial seizures. Neurologists’ ratings of overall severity of epilepsy at T1 ranged from “not at all severe” (19%) to very/quite/extremely severe (6%). The mean total HRQL scores at T1 was 70.5 (SD=13.9). Spearman rank-order correlations of the GASE score with the total QOLCE score at each of the 3 times were as follows: T1 - 0.146 (p=0.0078); T2 - 0.315 (p<0.0001); and T3 - 0.356 (p<0.0001). The correlations of the individual aspects of epilepsy, seizure severity and frequency, with the QOLCE total score were consistently slightly lower than those of GASE with the QOLCE. Conclusions: A global assessment of severity of epilepsy by pediatric neurologists was significantly correlated with children’s HRQL as reported by their parents; the correlation was weak shortly after diagnosis and moderate at six months and 12 months after diagnosis. This provides preliminary evidence that current severity of epilepsy is a factor in determining HRQL. We plan to investigate whether severity of epilepsy or change in severity of epilepsy from one assessment to the next is more important in determining HRQL. We also plan to assess the relative importance of severity of epilepsy within a multivariate, multilevel model incorporating factors on three levels: child, family and interactions with the health care system.