title: The Danish National Prescription Registry in studies of a biological pharmaceutical: palivizumab - validation against two external data sources.
abstract: BACKGROUND
  National prescription databases are important tools in pharmacoepidemiological studies investigating potential long-term adverse events after drug use. Palivizumab is a biological pharmaceutical used as passive prophylaxis against severe infection with respiratory syncytial virus in high-risk children.
  
  
  OBJECTIVE
  To assess the registration of palivizumab in the Danish National Prescription Registry (DNPR) and to examine if palivizumab reimbursement data obtained from the Danish Health and Medicines Authority could serve as a supplement to data from the DNPR.
  
  
  METHODS
  Registration of palivizumab exposure in the DNPR between 1999 and 2010 was compared to two external data sources: registration of palivizumab exposure in medical records, and palivizumab reimbursement data.
  
  
  RESULTS
  During the study period, 182 children with palivizumab exposure were registered in the DNPR. A total of 207 children were registered for palivizumab reimbursement. The sensitivity of palivizumab registration in the DNPR was 26% (20%-34%), and the specificity of no palivizumab registration in the DNPR was 97% (94%-99%), with data from the medical record as the reference. Palivizumab registration sensitivity in reimbursement data was 29% (22%-36%), and the specificity of no palivizumab registration in the DNPR was 97% (94%-99%), with data from the medical record as the reference.
  
  
  CONCLUSIONS
  Exposure to palivizumab was underestimated in the DNPR. Reimbursement data are a readily accessible data supplement, which only slightly increased the sensitivity of palivizumab registration in the DNPR. Our findings underline the need to improve DNPR information concerning drugs administered in hospitals.
authors.affiliation: The Child and Adolescent Clinic 4072, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark ; The Research Unit Women's and Children's Health, The Juliane Marie Centre for Women, Children and Reproduction, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Ann
authors.initials: A
authors.lastname: Haerskjold
authors.affiliation: The Research Unit Women's and Children's Health, The Juliane Marie Centre for Women, Children and Reproduction, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Lonny
authors.initials: L
authors.lastname: Henriksen
authors.affiliation: The Child and Adolescent Clinic 4072, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Susanne
authors.initials: S
authors.lastname: Way
authors.affiliation: Department of Pediatrics, Hvidovre University Hospital, Hvidovre, Denmark.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Malham
authors.affiliation: Department of Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Hallas
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Pedersen
authors.affiliation: The Child and Adolescent Clinic 4072, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Lone Graff
authors.initials: LG
authors.lastname: Stensballe
keywords: drug; health register; medical records; respiratory syncytial virus; validation