Deterioration of blood pressure control after discontinuation of a physician-pharmacist collaborative intervention

To assess blood pressure control after discontinuation of a physician-pharmacist collaborative intervention.

Comparative analysis of data of the patients who received the intervention versus a control group from a prospective, cluster-randomized, 9-month efficacy trial and the same patients' data 18 and 27 months after completion of the trial, abstracted from their medical records.

Five primary care medical offices operated by a university health system.

One hundred four patients with hypertension; 65 were in the intervention group, and 39 were in the control group.

In the prospective study, patients were randomized to receive a physician-pharmacist collaborative intervention to improve blood pressure control or to the control group. Systolic and diastolic blood pressures were measured by a research nurse at baseline and at the end of the study (9 mo later). In the current study, data were abstracted for blood pressure and blood pressure control at 18 and 27 months (9 and 18 mo, respectively, after discontinuation of the study). At baseline, mean +/- SD systolic blood pressure was 152.5 +/- 9.5 and 150.1 +/- 9.6 mm Hg in the intervention and control groups, respectively (p=0.22). At 9 months, systolic blood pressure decreased to 124.5 +/- 10.7 and 132.0 +/- 15.1 mm Hg (p=0.0038 between groups), and blood pressure was controlled in 78.5% and 48.7% (p=0.0017) of patients in the intervention and control groups, respectively. By 18 months, systolic blood pressure had deteriorated to 131.0 +/- 12.2 and 143.3 +/- 17.5 mm Hg (p<0.001), and blood pressure control rates decreased to 53.9% and 30.8% (p=0.02). By 27 months, systolic blood pressure was 131.3 +/- 13.0 and 141.2 +/- 15.8 mm Hg (p=0.0008), and blood pressure control was 55.4% and 35.9% (p=0.05).

A sustained positive effect on blood pressure control was noted up to 18 months after discontinuation of a physician-pharmacist collaborative intervention, when compared with a control group. Blood pressure control did deteriorate at a similar rate in both the intervention and control groups, but the percentage of patients with controlled blood pressure remained significantly higher in the intervention group. These results suggest that continued interventions by pharmacists may be necessary to maintain high rates of blood pressure control, especially in those patients whose blood pressure begins to increase.