Access to infant immunizations for poor, inner-city families: what is the impact of managed care?

California plans to enroll half of its Medicaid population, 75 percent of which are children, into managed care. To measure the impact of managed care on utilization of preventive services, we surveyed 867 families in two inner-city areas of Los Angeles and assessed the relationship between insurance type, source of care, and access to immunization services. Compared to children in public health clinics, those in private physicians' offices or health maintenance organizations (HMOs) had odds of being up-to-date on immunizations of 0.43 (p < .01) and 0.24 (p < .01), respectively. We conclude that in the absence of meaningful financial incentives to encourage private physicians and HMOs to provide immunizations to inner-city children, managed care is unlikely to improve immunization rates among this vulnerable population.