title: Birth prevalence rates of newborn screening disorders in relation to screening practices in the United States.
abstract: OBJECTIVE
  To examine the associations between the first-tier-screening laboratory methods and criteria and the birth prevalence of congenital adrenal hyperplasia (CAH), phenylketonuria (PKU), and the sickle hemoglobinopathies occurring in the United States between 1991 and 2000.
  
  
  METHODS
  By using validated data from the National Newborn Screening and Genetics Resource Center, we fit Poisson regression models with laboratory methods and criteria used in every year for each state for each disorder. We also examined whether there was an overall change in birth prevalence over the decade and whether there was an effect resulting from obligatory second screenings.
  
  
  RESULTS
  There were no associations among any of the factors and the birth prevalence of PKU in this decade. Use of the enzyme-linked immunosorbent assay was more likely than any other laboratory method to identify cases of CAH (OR 1.16; 95% CI 1.04-1.30), but no other factors were associated with this disorder. None of the factors examined were associated with the birth prevalence rates of any of the sickle hemoglobinopathies.
  
  
  CONCLUSIONS
  There were no substantial changes in the birth prevalence rates of PKU, CAH, or the sickle hemoglobinopathies over the study period despite rapid changes in technology.
authors.affiliation: Emory University, Rollins School of Public Health, Department of Biostatistics, Atlanta, GA, USA.
authors.forename: Vicki S
authors.initials: VS
authors.lastname: Hertzberg
authors.forename: Cynthia F
authors.initials: CF
authors.lastname: Hinton
authors.forename: Bradford L
authors.initials: BL
authors.lastname: Therrell
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Shapira
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000453:epidemiology*; D000755:Anemia, Sickle Cell / Q000453:epidemiology*; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D015200:Fluoroimmunoassay; D006801:Humans; D007231:Infant, Newborn; D015997:Neonatal Screening / Q000379:methods; D010661:Phenylketonurias / Q000453:epidemiology*; D015995:Prevalence; D053719:Tandem Mass Spectrometry; D014481:United States