OBJECTIVE -To use pharmacy and laboratory data to assess diabetes care within a medical group and between medical groups and to determine dispensing patterns and the extent to which providers change therapy based on HbA 1c results.RESEARCH DESIGN AND METHODS -Participating groups submitted 1 year of data for continuously enrolled patients. Required data included date of birth, all diabetes-specific prescriptions (oral hypoglycemic agents and insulin), date of prescription, National Drug Code, all HbA 1c values, lower and upper normal limits, and date of testing.RESULTS -Few changes in therapy were noted despite the large percentages of patients with suboptimal control. Nearly 90% of the patients treated with medications received a monotherapy regimen involving one of three therapeutic agents: sulfonylureas, metformin, or insulin. More than three-fourths of the patients remained on the same therapy during the observation period despite the fact that 27% of these patients had HbA 1c values Ն8%. Nearly onefifth (18%) of patients had an HbA 1c level of Ն8% and no further testing for at least 90 days after the "actionable" HbA 1c result was obtained. Furthermore, 54% of patients with actionable HbA 1c results did not have a change in therapy initiated after the result was available.CONCLUSIONS -The American Diabetes Association recommendations to act on HbA 1c values Ն8% and to follow up regularly on patients found to be in suboptimal control do not appear to be applied in a consistent manner based on the pharmacy and laboratory data analyzed in this sample.