THE CINCINNATI AED SIDE EFFECT SCALE (CASE SCALE): DEVELOPMENT AND VALIDATION OF A TOOL TO OBJECTIVELY MEASURE ANTIEPILEPTIC DRUG SIDE EFFECTS IN CHILDREN WITH EPILEPSY
Abstract number :
2.302
Submission category :
Year :
2003
Submission ID :
3678
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Diego A. Morita, Tracy A. Glauser, Mekibib Altaye, Steve R. Fordyce, Deborah L. Holder Division of Neurology, Cincinnati Children[apos]s Hospital Medical Center, Cincinnati, OH; Center for Epidemiology and Biostatistics, Cincinnati Children[apos]s Hospita
Antiepileptic drug (AED) side effects often occur early in therapy and manifest significant interpatient variability and clinical impact. For both clinical care and pharmacogenetic research, no reliable validated instrument currently exists to objectively measure AED side effects in children with recent onset epilepsy. We sought to develop a reliable and valid instrument that could be used in both clinical care and research to objectively measure AED toxicity.
Content development and validation was performed using existing medical literature, input from caretakers of children with epilepsy (n=21) and nationally recognized pediatric epilepsy experts (n=12). Each item was scored by the patients/parents on a scale ranging from 0 (not present) to 5 (high severity). Test-retest reliability was assessed in 17 children with new onset epilepsy. Internal consistency, reliability, and construct validity were further assessed in 440 children with epilepsy.
The 44-item questionnaire spanned 6 domains (neurologic, cognitive, behavioral/psychiatric, gastrointestinal, dermatologic, and systemic). For the 17 test-retest patients, the intraclass correlation was 0.96. For the 440 patients (10.7 [plusmn] 5.3 years), the average score was 15.3 [plusmn] 18.9 (range 0-109). The Cronbach[rsquo]s alpha test for homogeneity revealed a very high alpha coefficient (r = 0.92). The Spearman-Brown split-half test resulted in a highly significant reliability coefficient (r = 0.8, p[lt].001). With factor analysis for construct validity 13 factors were extracted, with a total explained variance of 68.7%. The first two factors, consisting of 11 questions, explained 31.4% of the variance.
The high reliable coefficients infer that the test halves are highly correlated and the instrument has a very high internal consistency. Preliminary factor analysis for construct validity shows that the original domains used to design the scale are consistent with the data obtained. Coupled with the content validity and the test-retest result, this AED side effect scale is reliable and valid in children with epilepsy. As seizure counts have served to quantify AED efficacy, the scores from this tool can be used in clinical care and in clinical research to quantify AED toxicity.
[Supported by: NIH NS40261 (TAG)]