Parent-completed scales for measuring seizure severity and severity of side-effects of antiepileptic drugs in childhood epilepsy: development and psychometric analysis

Abstract

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

Commission on Outcome Measurement in Epilepsy, 1994–1997: Final Report

“…A selfadministered scale such as the Liverpool Scale would require special adaptation for use by children to ensure that they could understand the questions and respond appropriately. Carpay et al (15) have initiated studies in this field.…”

The Personal Impact of Epilepsy Scale (PIES)

“…have evaluated the 44-item Impact of Childhood Neurologic Disability Scale to measure problems in the domains of epilepsy, cognition, behavioral, and physical/neurologic function [40]. An impact of epilepsy scale [41] can be completed by parents. Carpay and associates [42] developed the Hague Seizure Severity Scale for use in children and the Hague Side Effects Scale.…”

Measuring side effects of psychopharmacologic medication in individuals with mental retardation and developmental disabilities

“…Side Effects of Antiepileptic Drugs Scale [Carpay et al, 1996] 20-item scale in layperson's language specific to antiepileptic medication. Psychometrics provided.…”