Immunization coverage among infants enrolled in the Tennessee Medicaid program

M R Griffin1, J Daugherty, G W Reed

  • 1Department of Preventive Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.

Insights

Fewer than half of infants on Tennessee Medicaid completed recommended vaccinations by 24 months. Factors like mother's prior births and timing of first immunization impacted completion rates for childhood vaccines.

Area of Science:

  • Pediatric Health
  • Public Health Policy
  • Health Services Research

Background:

  • Infant immunization is critical for preventing childhood diseases.
  • Medicaid enrollees often face barriers to healthcare access, potentially impacting vaccination rates.
  • Understanding coverage gaps is essential for improving public health outcomes.

Purpose of the Study:

  • To assess immunization coverage among infants enrolled in Tennessee Medicaid.
  • To identify risk factors associated with incomplete vaccinations by 24 months of age.

Main Methods:

  • Retrospective cohort study of 33,615 infants enrolled in Medicaid in three Tennessee urban counties (1980-1989).
  • Assessed receipt of diphtheria-tetanus-pertussis, oral polio, and measles-mumps-rubella vaccines by 24 months.
  • Data sources included computerized county immunization records and Medicaid billing files.

Main Results:

  • Overall, only 45% of infants completed recommended vaccinations by 24 months.
  • Vaccination completion rates varied by county of birth (37%-63%) and decreased from 1982 (50%) to 1989 (44%).
  • Key predictors of completion included fewer prior births for the mother, timely first immunization, and county of birth; maternal demographics showed weak associations.

Conclusions:

  • Less than half of Tennessee Medicaid infants in the study completed recommended vaccinations by age two.
  • Significant disparities in immunization levels between counties, unexplained by demographics, suggest systemic issues in healthcare delivery.
  • Improving immunization coverage requires addressing health care and vaccine delivery system factors for this vulnerable population.
Abstract

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