title: The methodology of the Utah Birth Defect Network: congenital heart defects as an illustration.
abstract: OBJECTIVE
  The Utah Birth Defect Network (UBDN) uses a population-based birth defect surveillance system that has evolved from identifying only neural tube defects in 1994 to monitoring all structural malformations since 1999. All pregnancy outcomes are monitored statewide through intensive identification of potential cases using multiple reporting sources.
  
  
  METHODS
  The UBDN is a well-established statewide surveillance system that uses a combined approach, active and passive, in case ascertainment. Utah has the distinct advantage of having relatively few points of entry into the health care system both pre- and postnatally. A description of the UBDN methodology is presented and the completeness, validity and timing of reporting sources and diagnoses are illustrated using the example of congenital heart defects (CHD).
  
  
  RESULTS
  The UBDN identified a total of 2,115 potential CHD cases, of which 1,082 (51.2%) were determined to be true cases and 1,033 (48.8%) were classified as not a case (NAC). A single source was responsible for reporting 1,038 (49.1%) potential cases:241 (23.2%) were true cases, and the remaining 797 (76.8%) were classified as NAC and considered to be false positives.
  
  
  CONCLUSIONS
  This descriptive analysis of CHD cases collected through the UBDN's surveillance system illustrates the necessity--and benefit--of using multiple sources of ascertainment to ensure completeness of reporting.
authors.affiliation: University of Utah Health Sciences Center, Division of Medical Genetics, Salt Lake City, 84132, USA. mfeldkamp@utah.gov
authors.forename: Marcia
authors.initials: M
authors.lastname: Feldkamp
authors.forename: Lynne
authors.initials: L
authors.lastname: Macleod
authors.forename: Luciana
authors.initials: L
authors.lastname: Young
authors.forename: Kara
authors.initials: K
authors.lastname: Lecheminant
authors.forename: John C
authors.initials: JC
authors.lastname: Carey
mesh_terms: D001719:Birth Certificates; D000013:Congenital Abnormalities / Q000145:classification / Q000175:diagnosis* / Q000517:prevention & control*; D005260:Female; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D009436:Neural Tube Defects; D011159:Population Surveillance; D011247:Pregnancy; D011256:Pregnancy Outcome; D015995:Prevalence; D012042:Registries; D014589:Utah