Use of preventive services by managed care enrollees: an updated perspective.

We examined whether enrollees in managed care plans received more preventive services than enrollees in non-managed care plans did, by conducting an updated literature synthesis of studies published between 1990 and 1998. We found that 37 percent of comparisons indicated that managed care enrollees were significantly more likely to obtain preventive services; 3 percent indicated that they were significantly less likely to do so; and 60 percent found no difference. Enrollees in group/staff-model health maintenance organizations (HMOs) were more likely to receive preventive services, but there was little evidence, outside of Medicaid managed care, that managed care plans are worse at providing preventive services. However, most of the evidence is equivocal: Provision of preventive services was neither better nor worse in managed versus non-managed care plans. Because of the blurred distinctions among types of health plans, more research is needed to identify which plan characteristics are most likely to encourage appropriate utilization.