title: Improving the Completeness of Ascertainment in Florida's Birth Defects Surveillance Program: The Impact of Adding Infant Death and Emergency Department Data.
abstract: BACKGROUND
  The Florida Birth Defects Registry (FBDR) relies predominantly on a statewide, population-based, passive surveillance system constructed by linking together multiple administrative and clinical databases. With funding limitations and data restrictions a reality in public health, it is imperative for disease registries to have ongoing evaluation of existing and new data sources. This study quantifies the impact of expanding the FBDR case ascertainment net to include infant death certificates (IDCs) and emergency department (ED) discharge data on the reported prevalence of birth defects.
  
  
  METHODS
  Between 2008 and 2011, the FBDR identified cases using various data sources: inpatient and outpatient discharge data (2008-2011), Regional Perinatal Intensive Care Center data (2008), Early Steps program data (2008), IDCs (2009-2011), and ED data (2010-2011). Using hypothetical reconstructions of the FBDR, we examined the overall and unique contribution of each data source in identifying infants with birth defects. This permitted evaluation of a changing FBDR data source mix during the 4-year study period. The effect of adding both IDCs and ED data was investigated by constructing the 2010-2011 FBDR with and without these data sources, and then comparing frequencies and prevalence rates across each scenario. Analyses were conducted for all FBDR cases and for specific birth defect categories; improvements in ascertainment were assessed across sociodemographic and perinatal characteristics.
  
  
  RESULTS
  Overall, IDCs captured 3.4% of all infants with at least 1 birth defect studied, ED data captured 3.9% of the cases, and together the 2 data sources captured 7.2%. However, IDCs uniquely identified 0.8% of all cases, ED data uniquely identified 0.7% of all cases, and collectively they identified only 1.4% of cases that would otherwise have been missed. The unique contribution of IDC and ED data to case identification varied by defect and across sociodemographic and perinatal subgroups, with the largest impact among infants with anencephalus (64.7%), trisomy 13 (52.0%), trisomy 18 (22.2%), and encephalocele (13.3%), or those who were born weighing less than 1,500 grams or less than 32 weeks' gestation, or whose mothers' education was eighth grade or less.
  
  
  CONCLUSIONS
  Although their unique contribution is small when all defects are considered together, IDCs and ED data contribute cases that would otherwise have been disproportionately lost and are thus an important addition to surveillance activities. The FBDR continues to strive to create a comprehensive, accurate, and efficient statewide birth defects surveillance system.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Rutkowski
authors.forename: Jason L
authors.initials: JL
authors.lastname: Salemi
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Tanner
authors.forename: Suzanne B
authors.initials: SB
authors.lastname: Anjohrin
authors.forename: Jane A
authors.initials: JA
authors.lastname: Correia
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Watkins
authors.forename: Russell S
authors.initials: RS
authors.lastname: Kirby