title: Geographic variation in the age- and gender-specific prevalence and incidence of epilepsy: analysis of Taiwanese National Health Insurance-based data.
abstract: OBJECTIVE
  We studied geographic variation in age- and gender-specific prevalence and incidence of epilepsy in four different areas of Taiwan.
  
  
  METHODS
  By using large-scale, National Health Insurance (NHI)-based data from 2000-2003 in Taiwan, we identified 131,287 patients diagnosed with epilepsy (ICD code 345) receiving at least of one of 11 antiepileptic drugs (AEDs). Information on age, gender, and location were also collected. The multivariable Poisson regression analysis was used to assess the heterogeneity of the morbidity of epilepsy in different regions. External data validation was also performed to assess the accuracy of capturing epilepsy cases through our NHI data set.
  
  
  RESULTS
  The age-adjusted prevalence and incidence of epilepsy were 5.85 (per 1,000) between 2000 and 2003 and 97 (per 100,000 person-years) during the follow-up time from 2001 to 2003 in Taiwan. The sensitivity and specificity of ICD-9 coding for epilepsy in the NHI data set were 83.91% and 99.83%, respectively, resulting in a slight overestimation. Male patients had a higher probability of having epilepsy than did females. East Taiwan had significantly higher prevalence and incidence than did other areas. The age-specific incidence pattern in east Taiwan was atypical in that it revealed clustering in young and middle-aged groups.
  
  
  CONCLUSIONS
  Our study demonstrated geographic variation in epidemiologic patterns of epilepsy within Taiwan. The findings are informative and provide insight into the clinical management of epilepsy based on consideration of different target groups in different areas.
authors: Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
authors: Chih-Chuan
authors: CC
authors: Chen
authors: Li-Sheng
authors: LS
authors: Chen
authors: Ming-Fang
authors: MF
authors: Yen
authors: Hsiu-Hsi
authors: HH
authors: Chen
authors: Horng-Huei
authors: HH
authors: Liou
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D004827:Epilepsy / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data; D015995:Prevalence; D012959:Socioeconomic Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult