Impact of pharmacist consultations provided to patients with diabetes on healthcare costs in a health maintenance organization.

We conducted a study to assess the impact on healthcare utilization and costs of pharmacist consultations provided to patients with diabetes. Data for this study were derived from a larger study conducted by Kaiser Permanente and the University of Southern California that evaluated three alternative models of pharmacist consultations (control, state, and Kaiser). Computerized data were available for patient demographic characteristics and healthcare utilization. We used medication data to classify patient cohorts as insulin only or oral antidiabetics +/- insulin. We estimated hospitalization costs based on diagnostic related group and medication costs based on average wholesale price; office visits were estimated at $70 each. In the insulin only cohort, total costs for patients who had their prescriptions filled at a state model pharmacy were 7.8% less than those for patients filling prescriptions at a control model pharmacy (P = 0.008). In the oral +/- insulin cohort, total costs for patients filling new prescriptions at a Kaiser model pharmacy were 21.9% less than those for patients using a control model pharmacy (P = 0.0001). The state model also was negatively correlated (beta coefficient, -0.0997) with total costs (P = 0.0001). These data suggest that pharmacist consultations provided to patients with diabetes can decrease total healthcare costs in a health maintenance organization.