title: On-time vaccination coverage in premature infants in Ontario, 2002-2009.
abstract: OBJECTIVE
  Premature children are at increased risk of complications from vaccine-preventable diseases and should be vaccinated with the routinely recommended childhood vaccines at the same chronological age as full-term infants with the exception of the hepatitis B vaccine for infants of HBsAg-positive mothers. We sought to compare on-time vaccination levels in premature children for recommended vaccinations to levels in children born at term.
  
  
  METHODS
  Using linked health administrative databases, we compared the proportion of term (37+ wks), near term (33-36 wks), very premature (28-32 wks) and extremely premature (≤27 wks) children who received at least one vaccination during the 2-, 4- and 6-month vaccination visits within the recommended time period in the province of Ontario.
  
  
  RESULTS
  When we excluded children who were hospitalized at any time during the vaccination window, we identified that vaccination rates were within 3% of each other in the 4 categories examined. However, when we included infants who may have been hospitalized at any point during the on-time window, we observed substantially lower rates in the extremely premature children at 2 and 4 months and in the very premature children at 2 months.
  
  
  CONCLUSIONS
  Our study identifies the need to confirm whether vaccinations are given while premature children are in hospital during the time of their scheduled vaccinations.
authors.affiliation: Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON. kwilson@ohri.ca
authors.forename: Kumanan
authors.initials: K
authors.lastname: Wilson
authors.forename: Steven
authors.initials: S
authors.lastname: Hawken
authors.forename: Kirsten
authors.initials: K
authors.lastname: Holdt Henningsen
authors.forename: Jeffery C
authors.initials: JC
authors.lastname: Kwong
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Deeks
authors.forename: Natasha S
authors.initials: NS
authors.lastname: Crowcroft
authors.forename: Barbara
authors.initials: B
authors.lastname: Law
authors.forename: Doug G
authors.initials: DG
authors.lastname: Manuel
mesh_terms: D016208:Databases, Factual; D005865:Gestational Age; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007115:Immunization Schedule; D007231:Infant, Newborn; D007234:Infant, Premature; D009864:Ontario; D017410:Practice Guidelines as Topic; D014611:Vaccination / Q000706:statistics & numerical data*
keywords: Health Services Research; Immunization; Infant; Ontario; Premature; Vaccination