Effect of a telephone medication renewal service on blood pressure control

To evaluate the effect of a pharmacist-staffed telephone medication renewal service on blood pressure (BP) control.

Retrospective review of telephone call logs and patient charts.

University-based family medicine clinic.

All patients seen at the clinic with an International Classification of Diseases 9 code for hypertension during 2000.

Age, sex, diagnosis of heart failure and/or diabetes, and frequency of clinic visits were recorded. Telephoned prescription renewal requests for 2000 were logged; patient name, age, medication requested, strength, and directions were recorded. Each log entry was reviewed to identify patients requesting a renewal for an antihypertensive agent. Patients with hypertension who used the renewal service were compared with those who did not.

BP control rates were calculated for each group as the number of patients who met BP goals from the 1997 guidelines of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Analysis of variance and regression analysis were performed to examine the effect use of the renewal service had on BP control in both groups of patients. Covariables such as age, sex, and clinic visits were included in the model.

Of the 938 patients seen for hypertension, 332 used the renewal service at least once. We found no statistical difference between the two groups with respect to BP control (P = .86; confidence interval [CI], 0.7-1.3). BP control did not improve more for patients who used the renewal service more frequently (P = .48; CI, 0.9-1.2).

Use of the telephone medication renewal service had no effect on BP control. While increasing patients' access to medications is necessary, the results of this study suggest that this in itself is not sufficient to ensure good BP control.