Abstract
This study assessed the timeliness of immunization for children in a Medicaid managed care primary care case management program controlling for patient and provider predictors of immunization status. Using administrative data and patient medical records, up-to-date (UTD) and age appropriate immunization (AAI) status were reviewed for 5598 children. The 4:3:1 immunization series (four diphtheria, pertussis, tetanus vaccinations; three polio vaccinations; and one measles, mumps, rubella vaccination) was the standard. Childhood immunization rates were low when assessed using strict adherence to vaccination recommendations. At age 18 months, 28.3% were classified as UTD, and 6.3% were classified as AAI. Compared to children not up-to-date, UTD children were more likely to have public rather than private providers, to have had older mothers, and less likely to have been African American. Among UTD children, AAI children were more likely to reside in urban areas. Low-income children continue to be under-immunized, even under a managed care initiative. Health care providers and child health advocates need to continue pressure for programs that will increase adherence to nationally recommended guidelines.