title: Impact of varicella vaccination on varicella-related hospitalizations among American Indian/Alaska Native people.
abstract: BACKGROUND
  Routine childhood varicella vaccination, implemented in 1995, has resulted in significant declines in varicella-related hospitalizations in the United States. Varicella hospitalization rates among the American Indian (AI) and Alaska Native (AN) population have not been previously documented.
  
  
  METHODS
  We selected varicella-related hospitalizations, based on a published definition, from the Indian Health Service inpatient database for AI/ANs in the Alaska, Southwest and Northern Plains regions (1995-2010) and from the Nationwide Inpatient Sample for the general US population (2007-2010). We analyzed average annual hospitalization rates prevaccine (1995-1998) and postvaccine (2007-2010) for the AI/AN population, and postvaccine for the general US population.
  
  
  RESULTS
  From 1995-1998 to 2007-2010, the average annual varicella-related hospitalization rate for AI/ANs in the 3 regions decreased 95% (0.66-0.03/10,000 persons); the postvaccine rate appears lower than the general US rate (0.06, 95% confidence interval: 0.05-0.06). The rate declined in all AI/AN pediatric age groups. Infants experienced the highest prevaccine (14.07) and postvaccine (0.83) hospitalization rates. Adults experienced low rates in both periods. Varicella vaccination rates in 19- to 35-month-old AI/AN children during fiscal years 2008-2010 were 88.1-91.0%.
  
  
  CONCLUSIONS
  Widespread use of varicella vaccine in AI/AN children was accompanied by substantial declines in varicella-related hospitalizations consistent with high varicella vaccine effectiveness in preventing severe varicella outcomes.
authors.affiliation: From the *Alaska Native Tribal Health Consortium, Anchorage, AK; †Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Centers for Disease Control and Prevention (CDC), U.S. Department of Health and Human Services (USDHHS), Atlanta, GA; ‡Healthcare Cost and Utilization Project, Center for Delivery, Organization and Markets, Agency for Healthcare Research and Quality, USDHHS, Rockville, MD; §Indian Health Service (IHS), USDHHS, Santa Fe, NM; ¶Arctic Investigations Program, NCEZID, CDC, USDHHS, Anchorage, AK; ‖Immunization Services Division, CDC, USA USDHHS, Atlanta, GA; **Tuba City Regional Health Care, IHS, USDHHS, Tuba City, AZ; and ††Division of Viral Diseases, National Center for Immunization and Respiratory Disease, CDC, GA.
authors.forename: Rosalyn J
authors.initials: RJ
authors.lastname: Singleton
authors.forename: Robert C
authors.initials: RC
authors.lastname: Holman
authors.forename: Marissa K
authors.initials: MK
authors.lastname: Person
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Steiner
authors.forename: John T
authors.initials: JT
authors.lastname: Redd
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Hennessy
authors.forename: Amy
authors.initials: A
authors.lastname: Groom
authors.forename: Stephen
authors.initials: S
authors.lastname: Holve
authors.forename: Jane F
authors.initials: JF
authors.lastname: Seward
mesh_terms: D000328:Adult; D000413:Alaska / Q000453:epidemiology; D002644:Chickenpox / Q000453:epidemiology* / Q000517:prevention & control*; D019433:Chickenpox Vaccine / Q000008:administration & dosage*; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D014611:Vaccination / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D019433:Chickenpox Vaccine