Background: Underimmunization is distributed unevenly across populations, concentrated among the impoverished. Managed care has stimulated the development of quality indicators such as immunization rates to assess health status of populations.
Objective: To determine if enrollment in Medicaid managed care (MMC) improves quality of health care as reflected by immunization rates when compared with fee-for-service Medicaid (FFSM). DESIGN. Prospective cohort study of infants born between May 1994 and April 1995 with a 24-month follow-up period.
Setting: Urban teaching hospital and surrounding ambulatory settings.
Participants: Consecutive sample of infants (n = 644) enrolled in MMC or FFSM. Ninety-two percent of eligible patients were enrolled, and 87% completed follow-up.
Main outcome measure: Up-to-date immunization status.
Results: Seventy-three percent of the MMC and 72.4% of the FFSM patients were up-to-date on their immunizations: relative risk 1.01, (95% confidence interval [CI] 0.87, 1.17). No differences were found in age at immunization between the MMC and FFSM groups. After adjusting for other factors in multivariate analysis, insurance status remained unassociated with immunization status: adjusted odds ratio (OR) 1.04, (95% CI: 0.90, 1.10). Factors associated with up-to-date immunization included firstborn child, OR 2.28 (95% CI: 1.45, 3.60) and adequate maternal prenatal care, OR 2.24 (95% CI: 1.44, 3.48). Variables characterizing children less likely to be adequately immunized included father living in home with child, OR 0.53 (95% CI: 0.33, 0.85) and using private office-based primary care, OR 0.39 (95% CI: 0.23, 0.63).
Conclusions: Enrollment in MMC did not improve rates of immunizations when compared with FFSM.