title: The impact of DTaP-IPV-HB vaccine on use of health services for young infants.
abstract: BACKGROUND
  In 2003, a pentavalent vaccine (diphtheria, tetanus and acellular pertussis, injectable polio and hepatitis B) was introduced into the childhood vaccination schedule. A premarketing study showed a higher incidence of fever than with the vaccines administered separately. Because fevers in young infants prompt medical evaluations, this study examines the impact of this vaccine (DTaP-IPV-HB) on subsequent use of health services.
  
  
  METHODS
  We compared use of health services among 6- to 10-week-old infants receiving DTaP-IPV-HB (n = 1776) with a historical control receiving the prior schedule (n = 2162) at an inner-city practice network. Data sources included a hospital immunization registry and medical records. Outcome measures were visits to the emergency department and ambulatory practices, fever, tests, antibiotics and hospitalizations. Outcomes were stratified by age (<8, 8-10 weeks) and days since vaccination (3, 7).
  
  
  RESULTS
  Infants vaccinated with DTaP-IPV-HB were more likely to visit the ED (1.2% versus 0.6%, P = 0.03) and receive tests (47.6% versus 8.3%, P = 0.03) within 3 days of vaccination compared with the controls. Multivariate analysis showed infants vaccinated with DTaP-IPV-HB had a 7-fold increased risk of receiving a full sepsis workup and a 3-fold increased risk of receiving antibiotics within 7 days of vaccination. Medical evaluations decreased over time after implementation of the DTaP-IPV-HB vaccine. Concurrently, the rate of vaccination for infants <8 weeks markedly dropped.
  
  
  CONCLUSIONS
  The DTaP-IPV-HB vaccine was associated with increased use of health services in the emergency department, but these associations lessened over time. These findings reveal a conflict between the obligation of timely and efficient vaccination with the medical management of febrile young infants.
authors.affiliation: Division of General Pediatrics, University of Florida, Gainesville, FL 32608, USA. lathompson@peds.ufl.edu
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Thompson
authors.forename: Matilde
authors.initials: M
authors.lastname: Irigoyen
authors.forename: L Adriana
authors.initials: LA
authors.lastname: Matiz
authors.forename: Philip S
authors.initials: PS
authors.lastname: LaRussa
authors.forename: Shaofu
authors.initials: S
authors.lastname: Chen
authors.forename: Frank
authors.initials: F
authors.lastname: Chimkin
mesh_terms: D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D005334:Fever / Q000209:etiology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D008297:Male; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage / Q000009:adverse effects*; D014611:Vaccination / Q000009:adverse effects* / Q000379:methods; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D017325:Hepatitis B Vaccines; D011054:Poliovirus Vaccine, Inactivated; D017778:Vaccines, Combined