Table 3.

Risk Factors for Increased Numbers of Vaccination Sites, Increased Private Sector Vaccination, and Increased Vaccination Coverage

FactorVaccination Delivery CharacteristicsVaccination Coverage§
Vaccination Sites/1000 InfantsProportion of Infants Vaccinated in Private Sector
BivariateMultivariateBivariateMultivariateBivariateMultivariate
R2βPValueR2βPValueR2βPValueR2βPValueR2βPValueR2βPValue
MDs/1000
Pediatric.114+.853.015*[+1.194].001*.417+.024.001*+.037.001*.123+.004.012*+.006.001*
Family.119+.666.013*[+.790].001*.004−.002.658.015+.001.395
General.168+3.726.003*[+2.515].011*.025−.023.229.005+.003.620
Resident.013+4.872.433.149+.244.006*−.330.008*.027+.032.247
Demographic
Urban%.101−.200.023*.089+.003.034*.126−.001.011*−.002.001*
Minority%.046−.113.131.001+.001.967.034−.001.198
Economic
House Income.003+.001.686.304+.001.001*+.001.002*.001+.001.919
Medicaid Fee.032−.229.211.029−.003.235.002−.001.738
Vac. Distrib..247+.001*+.001*.066+.195.097+.087
First $ Insure.026+.254.006+.581.012+.436
Vac. character.
Sites/1000 Inf.NANANANANANA.132+.005.009*.117+.002.014*
Private Sector%.132+2.489.009*NANANANANANA.102+.098.022*
ModelNANANA.568NA.001*NANANA.627NA.001*NANANA.394NA.001*
  • NA indicates not applicable; blank, in multivariate analysis, factor not statistically significant at P < .05 level; [ ], β values calculated for physician concentrations in absence of inclusion of Vaccine Distribution System in model.

  • * Factor statistically significant at P < .05 level.

  • All factors but Vaccine Distrib. and First $ Insure are continuous variables.

  • Vaccination sites/1000 infants indicates ratio of total sites (public and private) providing routine childhood vaccinations divided by birth cohort and multiplied by 1000; private sector proportion, proportion of infants vaccinated entirely in the private sector, according to the 1997 National Immunization Survey.

  • § Vaccination coverage indicates 4-3-3-1 series completion at a median age of 27 months, according to 1997 National Immunization Survey.

    Resident = intern and resident physicians; Urban% = proportion of total population living in metropolitan statistical areas; Minority% = proportion of births that are other than non-Hispanic white; House. Income = median household income in dollars; Medicaid Fee = fee in dollars paid by Medicaid for administration of 3 vaccinations; Vaccine Distrib. = vaccine distribution system: (1) Universal; (2) Vaccines for Children (VFC) for public and private providers; or (3) VFC for public providers only. Since it is a categorical variable, β values are not calculated, but a plus sign is indicated in the β column if states with a Universal system had a higher mean value of the vaccination delivery characteristic or coverage than states with other distribution systems; First $ Insure = law requiring that vaccinations be reimbursed by third-party payers with no copayment or deductible: Yes or No. Since it is a categorical variable, β values are not calculated, but a plus sign is indicated in the β column if states with such a law had a higher mean value of the vaccination infrastructure characteristic or vaccination coverage than states without such a law.