Abstracts

Rationale: Canada’s National Longitudinal Survey of Children and Youth survey data provides for a longitudinal dataset with data collection beginning cycle 1 (1994-1995) and ending with cycle 8 (2008-2009).  Survey data was analyzed to assess temporal trends in the natural history of childhood epilepsy amongst survey participants. Methods: Using a unique identifier (PERSRUK) the responses to the survey question on epilepsy (HLTQ45) were tracked across the 8 cycles to determine whether the individual did or did not report epilepsy in each cycle. The data was analyzed to determine number of children reporting epilepsy, changing temporal trends and the duration of epilepsy over the period of the survey.  Non-responses between cycles were addressed using an imputation method. Results: There were 695 responses from 176 children/responders (M=89, F=87) representing 4 cohorts of children who reported the presence or absence of epilepsy in any of the 8 cycles.  These children with an age range 0-11 yrs. in cycle 1 grew up to be 14-25 yrs. in cycle 8. The number of cycles in which children reported to have epilepsy ranged to 1-7 cycles (mean=3.9 cycles). Of the total responders, 104 responders (59.09%)reported epilepsy in at least 1 cycle while 23 responders (13.07%) reported epilepsy through 4+ cycles.  Across age groups within responders, a bimodal distribution with peaks at 3-5 yrs. and at 9-11 yrs. is noted.  Conclusions: In this analysis of the longitudinal dataset from cycle 1-8 of the NLSCY, the proportion of children reporting epilepsy in 8 cycles  (1994-2009) demonstrate changing trends amongst age groupings,  with a bimodal peak (3-5 yrs., 9-11yrs.).  In about 13.07% of individuals in the survey, epilepsy persisted beyond over 4 cycles or 8 years. Funding: The present study with ANP as Principal Investigator is supported by the EPLINK theme grant of the Ontario Brain Institute (OBI).