Abstract
Our objective was to assess the capability of state administrative health care databases to evaluate the quality of immunization rates for a Medicaid managed care population. Data on 5599 2 year olds were obtained from a Medicaid claims database, a health department database, and the records of the children's assigned providers. The study was conducted on 1 managed care program in 1 state. Test performance ratio analyses were used to assess the relative accuracy and contribution of each source of administrative data. We found that of the 67,188 doses needed, 45,511 (68%) were documented as administered per at least 1 of the data sources. Medicaid claims data alone accounted for 18% of immunized children, while health department data used by itself accounted for 12%. Together, these 2 sources identified 34% of immunized children. Large administrative databases, such as Medicaid claims and data from a health department, while valuable sources of information on quality, may underestimate outcomes such as immunization rates. Assessments of the quality of health care should rely on a combination of administrative data and providers' records as sources of information.