Evaluation of pharmacist-managed diabetes mellitus under a collaborative drug therapy agreement

The effect of a pharmacist-managed collaborative drug therapy agreement (CDTA) on diabetes mellitus (DM) management in an outpatient setting is evaluated.

Patients with DM were referred by physicians to the pharmacist for either education or clinical management of DM under the CDTA. A retrospective chart review was conducted between September 2001 and December 2005 and included patients who had laboratory values of interest within one year before and after the initial visit and who had more than two documented visits with the pharmacist. After the pharmacist's intervention in the DM management, glycosylated hemoglobin (HbA(1c)) and low-density lipoprotein cholesterol were compared using a paired sample t test. Average costs for inpatient hospitalization and emergency department (ED) admission were also compared.

A total of 110 patients had a mean +/- S.D. of 5.7 +/- 3.9 visits with the pharmacist. A mean reduction in HbA(1c) of 0.7% (p < or = 0.001, n = 93) from 8.9% to 8.2% and a mean reduction in blood glucose of 26.4 mg/dL (p < or = 0.001, n = 99) were achieved. Average costs for inpatient hospitalization and ED admissions were significantly higher in the preintervention period than in the postintervention period for patients with DM as the primary or secondary diagnosis ($2434 versus $636, respectively; p = 0.015). For patients with a primary diagnosis of diabetes, preintervention costs were higher than postintervention costs, but this difference was not significant ($3082 versus $696, respectively; p = 0.100).

Pharmacist interventions under a CDTA resulted in significant improvements in glucose and HbA(1c) levels in patients with DM. Postintervention costs for inpatient hospitalization and ED services were significantly less than preintervention costs when DM was a primary or secondary diagnosis for the admission.