title: Health insurance for low-income working families. Effect on the provision of immunizations to preschool-age children.
abstract: BACKGROUND
  The out-of-pocket cost for immunizations is a cause for referral to public health department clinics and is associated with delayed immunization. In 1991, New York State started Child Health Plus (CHPlus), an insurance program that covers ambulatory care and immunization services for children of families earning less than 222% of the poverty level.
  
  
  OBJECTIVE
  To determine the effect of CHPlus on the provision of immunizations.
  
  
  METHODS
  A before-and-after design was used to compare the year immediately before enrollment in CHPlus with the first year after enrollment in CHPlus. A mixed-model analysis of variance was used to control for the effects of age.
  
  
  METHODS
  All area primary care practices (n = 164) and public health department clinics (n = 6).
  
  
  METHODS
  Children (n = 1730) younger than 6 years who were enrolled in CHPlus.
  
  
  METHODS
  Number of immunization visits; types of providers (public health department clinics or primary care providers [pediatricians and family physicians]); and series-complete immunization coverage, including the diphtheria toxoid, tetanus toxoid, and pertussis vaccine, the oral poliovirus vaccine, and the measles, mumps, and rubella vaccine.
  
  
  RESULTS
  The average age of the children was 37.7 months, 85% were white, 50% had been uninsured for immunizations before enrollment in CHPlus, and 16% previously received Medicaid. For infants, CHPlus decreased immunization visits to public health department clinics by 37% (from 0.14 to 0.09 visits per child, P = .009), increased immunization visits to primary care providers' offices by 15% (from 2.3 to 2.7 visits per child, P = .001), and increased immunization coverage by 7% (from 76% to 83%, P = .03). For children aged 1 to 5 years, CHPlus decreased visits to public health department clinics by 67% (from 0.06 to 0.02 visits per child, P < .001), increased visits to primary care providers' offices by 27% (from 0.46 to 0.59 visits per child, P < .001), and increased immunization coverage by 5% (from 83% to 88%, P < .001). The effects were greatest among previously uninsured children and among those with a gap in insurance coverage that was longer than 6 months.
  
  
  CONCLUSIONS
  Insurance coverage for low-income working families resulted in a shift in the provision of immunizations from the health department to primary care providers and in increased immunization coverage.
authors.affiliation: Department of Pediatrics, University of Rochester, NY, USA. lar9@cdc.gov
authors.forename: L E
authors.initials: LE
authors.lastname: Rodewald
authors.forename: P G
authors.initials: PG
authors.lastname: Szilagyi
authors.forename: J
authors.initials: J
authors.lastname: Holl
authors.forename: L R
authors.initials: LR
authors.lastname: Shone
authors.forename: J
authors.initials: J
authors.lastname: Zwanziger
authors.forename: R F
authors.initials: RF
authors.lastname: Raubertas
mesh_terms: D000553:Ambulatory Care / Q000191:economics; D000704:Analysis of Variance; D002662:Child Health Services / Q000191:economics*; D002675:Child, Preschool; D004651:Employment; D005260:Female; D006302:Health Services Research; D006801:Humans; D017589:Immunization Programs / Q000191:economics* / Q000592:standards; D007223:Infant; D019458:Insurance Coverage; D008297:Male; D017057:Medically Uninsured; D009518:New York; D011203:Poverty; D012189:Retrospective Studies; D013221:State Health Plans / Q000191:economics*; D014481:United States