title: Prevalence and morbidity of primary immunodeficiency diseases, United States 2001-2007.
abstract: OBJECTIVE
  Few studies have estimated population prevalence and morbidity of primary immunodeficiency diseases (PIDD). We used administrative healthcare databases to estimate the prevalence of PIDD diagnoses in the United States from 2001 to 2007.
  
  
  METHODS
  MarketScan databases compile claims from commercial health insurance plans and Medicaid, recording individual diagnoses for outpatient encounters and hospital stays. We used a cross sectional survey to estimate prevalence of PIDD using related ICD-9 codes (279.0, 279.1, 279.2, 279.8, 279.9, 288.1 and 288.2). Persons with secondary immunodeficiency diagnoses were excluded from analysis.
  
  
  RESULTS
  Between 2001 and 2007, prevalence of any PIDD diagnosis increased from 38.9 to 50.5 per 100,000 among privately insured and from 29.1 to 41.1 per 100,000 among publicly insured persons. B cell defects predominated. Prevalence was more than twice as high among Whites as among Blacks or Hispanics.
  
  
  CONCLUSIONS
  In this large database, we found a higher prevalence of diagnosed PIDD than has been reported previously from registries. Increased awareness may have contributed to the increasing prevalence.
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, 2015 Uppergate Dr., Atlanta, GA, 30322, USA, lkobryn@emory.edu.
authors.forename: Lisa
authors.initials: L
authors.lastname: Kobrynski
authors.forename: Rachel Waltenburg
authors.initials: RW
authors.lastname: Powell
authors.forename: Scott
authors.initials: S
authors.lastname: Bowen
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000453:epidemiology* / Q000401:mortality / Q000503:physiopathology; D007223:Infant; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D044469:Racial Groups; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology