Development and validation of a case definition for epilepsy for use with administrative health data.
The objective of this study was to develop and validate coding algorithms for epilepsy using ICD-coded inpatient claims, physician claims, and emergency room (ER) visits. 720/2049 charts from 2003 and 1533/3252 charts from 2006 were randomly selected for review from 13 neurologists' practices as the "gold standard" for diagnosis. Epilepsy status in each chart was determined by 2 trained physicians. The optimal algorithm to identify epilepsy cases was developed by linking the reviewed charts with three administrative databases (ICD 9 and 10 data from 2000 to 2008) including hospital discharges, ER visits and physician claims in a Canadian health region. Accepting chart review data as the gold standard, we calculated sensitivity, specificity, positive, and negative predictive value for each ICD-9 and ICD-10 administrative data algorithm (case definitions). Of 18 algorithms assessed, the most accurate algorithm to identify epilepsy cases was "2 physician claims or 1 hospitalization in 2 years coded" (ICD-9 345 or G40/G41) and the most sensitive algorithm was "1 physician clam or 1 hospitalization or 1 ER visit in 2 years." Accurate and sensitive case definitions are available for research requiring the identification of epilepsy cases in administrative health data.
Department of Clinical Neurosciences and Hotchkiss Brain Institute, University of Calgary, Canada.
Aylin Y
AY
Reid
Christine
C
St Germaine-Smith
Mingfu
M
Liu
Shahnaz
S
Sadiq
Hude
H
Quan
Samuel
S
Wiebe
Peter
P
Faris
Stafford
S
Dean
Nathalie
N
Jetté
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016208:Databases, Factual / Q000706:statistics & numerical data; D004827:Epilepsy / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data*; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult