title: Initiation & completion rates of hepatitis A vaccination among US pediatric populations born between 2005 and 2009.
abstract: OBJECTIVE
  To estimate hepatitis A vaccine series initiation and completion rates, assess time to vaccination, identify missed opportunities for the hepatitis A vaccine series, and examine factors associated with hepatitis A vaccine series initiation and completion.
  
  
  METHODS
  We conducted a retrospective, observational study using three healthcare claims databases separately. The study population was comprised of children born between years 2005 and 2009 that were continuously enrolled for at least three and a half years from the date of birth. Every child was followed from date of birth for three and a half years for hepatitis A vaccination.
  
  
  RESULTS
  There were 93,735 eligible children from Clinformatics Data Mart, 202,513 from MarketScan Commercial, and 207,545 from MarketScan Medicaid. The overall hepatitis A vaccine series initiation rate was 63.8-79.4% and completion rate was 45.1-66.8% across the three databases. About 62.8-90.1% of the children who never initiated hepatitis A vaccine had at least one well visit from 1 year to three and a half years old. Children were more likely to initiate and complete the hepatitis A vaccine series if they were from more recent birth cohorts, from states with a hepatitis A vaccination recommendation prior to the ACIP universal recommendation, from states with daycare/school entry requirements, were enrolled in an HMO health plan, had pediatricians as primary providers, had more doctor's office/well visits and received MMR/Varicella vaccines.
  
  
  CONCLUSIONS
  In this study, approximately one in every three to five children remained unvaccinated against hepatitis A. Although the hepatitis A vaccine series initiation and completion improved from 2005 to 2009, vaccine coverage has stabilized in recent years. It is important for providers to identify every opportunity for hepatitis A vaccination and to assure that children get protection from this vaccine-preventable disease.
authors.affiliation: Center for Observational and Real-World Effectiveness, Merck & Co., Inc., Kenilworth, NJ, USA. Electronic address: Thomas_weiss@merck.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Weiss
authors.affiliation: Center for Observational and Real-World Effectiveness, Merck & Co., Inc., Kenilworth, NJ, USA.
authors.forename: Dongmu
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Agile-1 for Merck & Co., Inc., Kenilworth, NJ, USA.
authors.forename: Nagesh N
authors.initials: NN
authors.lastname: Borse
authors.affiliation: Duke Clinical Vaccine Unit, Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA.
authors.forename: Emmanuel B
authors.initials: EB
authors.lastname: Walter
mesh_terms: D002675:Child, Preschool; D005260:Female; D019983:Guideline Adherence; D006506:Hepatitis A / Q000517:prevention & control*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055118:Medication Adherence; D012189:Retrospective Studies; D014481:United States
chemical_list: D022362:Hepatitis A Vaccines
keywords: Completion; Healthcare claims databases; Hepatitis A; Initiation; Observational study; Pediatric; Rates; US; Vaccination