CONCLUSION: Officially labeled lab-pharmacy interactions/warnings are frequent±totaling 249 (6.2/drug for commonly prescribed drugs, and 238 (6.4/drug) for NME's)±a number that exceeds the unaided prescribers' abilities to remember and monitor. Automated screening and reminders will need to be programmed into routine prescribing processes to prevent errors related to such interactions. A noteworthy discrepancy exists between number of toxicities and recommended monitoring, and relatively few drugs (especially NME's) appear to have lab interference evaluated, suggesting a need for additional research to ensure safe prescribing and error-free lab test interpretation. To assess racial disparities in influenza vaccination among Medicare beneficiaries and evaluate whether or not the magnitude of racial disparities is smaller for those enrolled in managed care than among those with fee-for-service insurance. METHODS: We analyzed 13,674 responses to the 1996 Medicare Current Beneficiary Survey of African American and white Medicare beneficiaries with managed care and fee-for-service insurance. We compared sociodemographic characteristics and health attitudes among the groups, the proportion receiving influenza vaccination, and differences in racial disparities in influenza vaccination between those with managed care and fee-for-service insurance. Using a propensity model based on sociodemographics, comorbid illnesses, attitudes toward health care, and their interactions with race, we adjusted for differences in the two insurance groups and compared the adjusted racial disparities. RESULTS: Eight percent were African American. Eleven percent were enrolled in managed care. On average, African Americans and fee-for-service enrollees were older, had worse health status, had a higher prevalence of diabetes, and were more likely to avoid doctor visits. Overall, 65.8% of Medicare beneficiaries received influenza vaccination. Whites were much more likely than African Americans to receive influenza vaccination (67.7% vs. 45.1%, absolute disparity = +21.6%; 95% C.I. 18.2% to 25.0%). Managed care enrollees were more likely to receive influenza vaccination than those with fee-for-service insurance (71.2% vs. 65.4%, difference = +5.8%; 95% C.I. 3.3% to 8.3%); however racial disparities in influenza vaccination were nearly identical among beneficiaries both with managed care and with fee-for-service insurance. These disparities were not significantly different after adjustment for propensity to enroll in managed care. CONCLUSION: While managed care is associated with higher rates of influenza vaccination, we found no evidence that managed care reduces racial disparities in influenza vaccination. Our results suggest that health plans are not yet adequately addressing racial disparities in the use of preventive services.