title: Guillain-Barré syndrome incidence in a large United States cohort (2000-2009).
abstract: OBJECTIVE
  We describe the incidence of Guillain-Barré syndrome (GBS) in a large United States cohort.
  
  
  METHODS
  Between 2000 and 2009, we identified visits with an ICD-9 code for GBS (357.0) from all persons with continuous enrollment for at least 1 year. The primary case definition was restricted to emergency department and inpatient visits. We calculated age-standardized rates and used multivariate Poisson regression to assess variation in rates by sex, age, season and year of diagnosis. We tabulated descriptive characteristics and the positive predictive value (PPV) for a subset of the visits with available medical record review.
  
  
  RESULTS
  1,619 visits with the GBS ICD-9 code were identified from 50,290,898 person-years of observation. After considering the PPV (55%) for record-reviewed visits, the age-standardized incidence rate was approximately 1.72/100,000 person-years. The rate was 40% higher for males and increased by 50% for every 10-year increase in age. The rate was 15% higher in winter and spring compared with summer. Rates were higher in more recent years.
  
  
  CONCLUSIONS
  GBS rates are higher in males and increase considerably with age. The potential reasons for differences in rates by season and the increased rates in more recent years should be further investigated.
authors: Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA 02115, USA. ishui@hsph.harvard.edu
authors: Irene M
authors: IM
authors: Shui
authors: Melisa D
authors: MD
authors: Rett
authors: Eric
authors: E
authors: Weintraub
authors: Michael
authors: M
authors: Marcy
authors: Anthony A
authors: AA
authors: Amato
authors: Sarah I
authors: SI
authors: Sheikh
authors: Doreen
authors: D
authors: Ho
authors: Grace M
authors: GM
authors: Lee
authors: W Katherine
authors: WK
authors: Yih
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D020275:Guillain-Barre Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D012621:Seasons; D012737:Sex Factors; D014481:United States / Q000453:epidemiology