Abstract Details

Title Definitions of Refractory Epilepsy for Administrative Claims Data Research

Topic General Neurology

Presentation(s) Neuroepidemiology Posters (7:00 AM-5:00 PM)

Poster/Presentation
Number 010

Background Effective interventions for refractory epilepsy are underutilized and large-scale investigations of drivers of underutilization could inform better care.

Objective

To evaluate refractory epilepsy definitions for administrative claims data.

Design/Methods We reviewed electronic medical records (EMR) from a tertiary health system from 2014-2020. We randomly sampled 450 patients with >1 epilepsy/convulsion encounter and >2 distinct antiseizure medications (ASMs); exclusion criteria were <2 years of EMR data or missing diagnosis data. We established refractory epilepsy diagnosis at a specific visit by reviewing EMR data through that date and employed a rubric based in the 2010 International League Against Epilepsy definition. We queried billing claims and performed logistic regressions to assess predictors of refractory epilepsy and inform claims-based definitions.

Results

Of 450 patients reviewed, 150 were excluded for insufficient EMR data. Of the 300 patients included, 98 (33%) met criteria for current refractory epilepsy. The strongest predictors of current refractory epilepsy were refractory epilepsy diagnosis code (OR 16.9, 95%CI 8.8-32.2), >2 ASMs in the prior two years (OR 13.0, 95%CI 5.1-33.3), >3 epilepsy-specific ASMs (OR 10.3, 95%CI 5.4-19.6), neurology visit (OR 10.0, 95%CI 4.4-22.7), neurosurgery visit (OR 45.2, 95% CI5.9-344.3), ER visit/admission for epilepsy/convulsion after the third ASM (OR 8.5, 95%CI 4.5-16.1), and epilepsy surgery (OR 30.7, 95%CI 7.1-133.3). We created claims-based refractory epilepsy definitions to: 1) maximize sensitivity (refractory epilepsy diagnosis or >2 ASMs in prior two years; sensitivity 0.95, specificity 0.63), 2) maximize specificity (>3 specific ASMs, ER visit/admission for epilepsy/convulsion, no psychogenic/functional encounters; specificity 0.96, sensitivity 0.39), and 3) maximize agreement between chart-based and claim-based diagnoses (refractory epilepsy diagnosis code; agreement 0.78, sensitivity 0.86, specificity 0.74).

Conclusions Our findings provide new validated claims-based definitions of refractory epilepsy. While no definition achieved both high sensitivity and specificity, we identified definitions that have sufficient validity for a variety of research questions.

Authors/Disclosures
Chloe E. Hill, MD (University of Michigan) PRESENTER	The institution of Dr. Hill has received research support from NIH. The institution of Dr. Hill has received research support from AAN. The institution of Dr. Hill has received research support from NIH. Dr. Hill has a non-compensated relationship as a member of AAN Health Services Research Subcommittee with AAN that is relevant to AAN interests or activities.
Chun Chieh Lin, PhD (University of Michigan)	The institution of Chun Chieh Lin has received research support from AAN.
Samuel W. Terman, MD (University of Michigan, Neurology Dept)	Dr. Terman has received research support from American Epilepsy Society. Dr. Terman has received research support from Epilepsy Study Consortium. Dr. Terman has received research support from New York University. Dr. Terman has received personal compensation in the range of $100,000-$499,999 for serving as a clinician scientist trainee for Susan S Spencer award with American Academy of Neurology.
Lesli Skolarus, MD	The institution of Dr. Skolarus has received research support from NIH.
James F. Burke, MD (Ohio State Wexner Medical Center)	Dr. Burke has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Heart Association/Circulation: Cardiovascular quality and outcomes.