Nurse-led adherence support in hypertension: a randomized controlled trial

Background. Lack of medication adherence is a common reason for poor control of blood pressure in the community, increasing the risk of heart attacks and strokes. Objective. To evaluate the effect of nurse-led adherence support for people with uncontrolled high blood pressure compared with usual care. Methods. We recruited 245 women and men with uncontrolled hypertension (>= 150/90 mmHg) from 21 general practices in Bristol, UK. Participants were randomized to receive nurse-led adherence support or usual care alone. Main outcome measures were adherence to medication ('timing compliance') and blood pressure. Results. Mean baseline timing compliance (+/- SD) was high in both the intervention (90.8 +/- 15.6%) and the control group (94.5 +/- 7.6%). There was no evidence of an effect of the intervention on timing compliance at follow-up (adjusted difference in means -1.0%; 95% confidence interval (CI) -5.1 to 3.1). There was also no difference at follow-up between the groups with regard to systolic blood pressure (-2.7 mmHg; 95% CI -7.2 to 1.8) or diastolic blood pressure (0.2 mmHg; 95% CI -1.9 to 2.3). Projected costs for the primary care sector per consultation were 6.60 pound for the intervention compared with 5.08 pound for usual care. Conclusion. In this study, adherence to blood pressure medication was much higher than previously reported. There was no evidence of an effect of nurse-led adherence support on medication adherence or blood pressure compared with usual care. Nurse-led adherence support was also more expensive from a primary care perspective.