Effect of nurse-directed hypertension treatment among First Nations people with existing hypertension and diabetes mellitus: the Diabetes Risk Evaluation and Microalbuminuria (DREAM 3) randomized controlled trial

Abstract

Background: First Nations people with diabetes mellitus and hypertension are at greater risk of renal and cardiovascular complications than are non-native patients because of barriers to health care services. We conducted this randomized controlled trial to assess whether a community-based treatment strategy implemented by home care nurses would be effective in controlling hypertension in First Nations people with existing hypertension and type 2 diabetes.

Methods: We compared 2 community-based strategies for controlling hypertension in First Nations people with existing hypertension and diabetes. In the intervention group, a home care nurse followed a predefined treatment algorithm of pharmacologic antihypertensive therapy. In the control group, treatment decisions were made by each subject's primary care physician. The primary outcome measure was the difference between the 2 groups in the change in systolic blood pressure after 12 months. Secondary outcome measures were the change in diastolic blood pressure over time, the change in urine albumin status and the incidence of adverse events.

Results: Both groups experienced a significant reduction in systolic blood pressure by the final visit (by 24.0 [standard deviation (SD) 13.5] mm Hg in the intervention group and by 17.0 [SD 18.6] mm Hg in the control group); p < 0.001 in each case). However, the difference between the 2 groups in this change was not significant. Patients in the intervention group had a larger decrease in diastolic blood pressure over time than did those in the control group (by 11.6 [SD 10.6] mm Hg v. 6.8 [SD 11.1] mm Hg respectively; p = 0.05). The groups did not differ significantly in terms of changes in urine albumin excretion or incidence of adverse events.

Interpretation: High rates of blood pressure control in the community were achieved in both groups in the DREAM 3 study. The addition of a home care nurse to implement a treatment strategy for blood pressure control was more effective in lowering diastolic than systolic blood pressure compared with home care visits for blood pressure monitoring alone and follow-up treatment by a family physician.

Box 1

Fig. 1: Hypertension management algorithm followed by home care nurses for patients assigned to the intervention group. Patients were given irbesartan at a starting dose of 150 mg/d. During subsequent visits, if the blood pressure (BP) was greater than the target level, the regimen was stepped up according to the protocol. Verapamil was prescribed in a long-acting format. Note: HCTZ = hydrochlorothiazide.

Fig. 2: Flow of patients through the study. R = randomization, RAS = renal artery stenosis.