title: The effect of lack of insurance, poverty and paediatrician supply on immunization rates among children 19-35 months of age in the United States.
abstract: OBJECTIVE
  Previous studies found that the increasing number of paediatricians in the United States was associated with improved childhood immunization coverage, while the increasing poverty level and the lack of health insurance reduced access to health care. We evaluated whether changes in the number of paediatricians, poverty level and health insurance affected national childhood immunization coverage in the state levels of the United States.
  
  
  METHODS
  Data were collected primarily from the US National Immunization Surveys, series 4:3:1:3:3 from years 1995 and 2003. Ordinal logistic regression analysis was used to analyse the relationships among variables.
  
  
  RESULTS
  Over 8 years studied, immunization coverage increased for children aged 19-35 months from 52.3% to 79.8% in the 50 states. The average number of paediatricians per 1000 births increased 28.7% while the percentage of children without health insurance declined 15.6%, and the percentage of children who lived in poverty level declined 17.3%. In 1995, the states with higher immunization coverage were associated with higher numbers of paediatricians [odds ratio (OR), 32.73; 95% confidence interval (CI), 5.96-179.77]. In 2003, the higher numbers of paediatricians still played a role in the increased immunization coverage (OR, 4.69; 95% CI, 1.01-21.78); however, the higher rate of uninsured children in 2003 had an even greater effect upon immunization coverage. Compared with states with lower rates of uninsured children, states with intermediate and higher rates of uninsured children had sixfold (OR, 0.16; 95% CI, 0.03-0.81) and 16-fold (OR, 0.06; 95% CI, 0.01-0.40) decreased childhood immunization coverage, respectively.
  
  
  CONCLUSIONS
  Between 1995 and 2003 in the United States, the lack of health insurance became more prominent than the supply of paediatricians in affecting immunization coverage for children aged 19-35 months. Future improvements in insurance coverage for children will likely lead to greater immunization coverage.
authors.affiliation: Department of Pediatrics, Medical College of Georgia, Augusta, GA, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Becton
authors.forename: Lee
authors.initials: L
authors.lastname: Cheng
authors.forename: Linda Z
authors.initials: LZ
authors.lastname: Nieman
mesh_terms: D002675:Child, Preschool; D019538:Health Care Surveys; D006801:Humans; D017589:Immunization Programs / Q000706:statistics & numerical data*; D007223:Infant; D016015:Logistic Models; D017057:Medically Uninsured; D010372:Pediatrics; D010820:Physicians / Q000600:supply & distribution*; D011203:Poverty; D014481:United States