Prevalence and morbidity of primary immunodeficiency diseases, United States 2001-2007

Abstract

Purpose: 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.

Conclusion: 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.

Fig. 1

Prevalence of Primary Immunodeficiency diseases by age for: a Commercial Claims and Encounters - pediatric age ranges 0–21; b Medicaid patients for all PIDD; c Medicaid patients for B cell defects, and d for T cell defects

Fig. 2

Mean Length of Stay (in days) in 2005 for Primary Immunodeficiency disease patients, Commercial Claims and Encounters (CCE) and Medicaid (MC)

Fig. 3

Mean prevalence per 100,000 persons with 95 % confidence interval for comorbidities associated with hospitalization for persons with primary immunodeficiency disease for Commercial Claims and Encounters (CCE) and Medicaid (MC)