IS UNDERIMMUNIZATION A MARKER FOR INSUFFICIENT UTILIZATION OF PREVENTIVE AND PRIMARY-CARE

Objective: To test the hypothesis that the underimmunization of young children is a marker for the lack of preventive and acute primary care . Setting: Primary care center serving an impoverished population (90% Medicaid). Design: Historical cohort study (N=1178) of children aged 12 to 30 months that determined each child's immunization status; anem ia, tuberculosis, and lead screening status; and office utilization hi story. Screening delay was defined as missing a recommended screening by more than 3 months past the standard screening age. Results: Thirty -four percent of the population were underimmunized at 12 months of ag e. Compared with fully immunized children, these children were at grea ter risk for screening delay: anemia, 38% vs 5% (risk ratio [RR], 7.5; 95% confidence interval [CI], 5.4 to 10.4); tuberculosis, 76% vs 44% (RR, 1.7; CI, 1.6 to 1.9); and lead, 69% vs 33% (RR, 2.1; CI, 1.9 to 2 .4). These RRs increased with greater immunization delay. Compared wit h fully immunized children, the underimmunized group made 47% fewer pr eventive health visits (2.5 vs 4.7 visits per infant per year, P<.001) and 43% fewer illness Visits (2.5 vs 4.4, P<.001) and had 50% more mi ssed appointments (2.1 vs 1.4, P<.001). Logistic regression, predictin g anemia screening delay at 12 months of age, showed that underimmuniz ation had an effect independent of utilization, with an odds ratio of 7.7 (CI, 5.2 to 12.0). Conclusion: Underimmunization was a powerful, i ndependent marker for inadequate health supervision in this population . Implications: The current emphasis on immunizations has the benefit of targeting children at risk of lack of preventive and acute care. Im proving immunization rates may have the potential to improve other asp ects of primary care if immunization provision is not uncoupled from p rimary care.