PARENT-COMPLETED SCALES FOR MEASURING SEIZURE SEVERITY AND SEVERITY OF SIDE-EFFECTS OF ANTIEPILEPTIC DRUGS IN CHILDHOOD EPILEPSY - DEVELOPMENT AND PSYCHOMETRIC ANALYSIS

We have developed two outcome measures for childhood epilepsy: a seizu re severity (SS) scale and a side-effects (SE) scale. Both scales have been designed for completion by parents. The scales were tested in tw o pilot phases and the results of this stepwise analysis an described here. The final scales' psychometric properties were assessed in a gro up of 80 children with active epilepsy, representative of the populati on at whom the scales were aimed: children with chronic epilepsy, aged 4-16 years, including all seizure types and epilepsies, as well as ch ildren with neurological comorbidity. The SS scale and SE scale showed good internal consistency and test-retest stability. Although there w as a significant positive correlation between the SS scale and the SE scale, this was low, indicating that the scales measure a different cl inical trait. The SE scale consisted of two subscales: a Toxic subscal e, measuring the severity of dose-related side-effects, and a Chronic subscale, measuring the severity of long-term behavioural and cognitiv e side-effects. These subscales for side-effects showed a high correla tion and can be used as a joint scale. These scales have the potential to improve outcome assessment in childhood epilepsy and they can be u sed to assess important aspects of quality of life in this population.