In patients with hypertension, adherence to treatment recommendations has a major impact on health outcomes and the costs of care. Some of the better recognized determinants of adherence to antihypertensive therapy are related to drug treatment such as drug tolerability and regimen complexity. Thus, reduced side-effects, fewer daily doses of antihypertensives, monotherapies and fewer changes in antihypertensive medications have all been associated with better adherence (14-16).
In a landmark study conducted by Morisky et al. (17), patients were assigned to three adherence-promoting interventions: physician counselling, family support for monitoring pill taking, group sessions with a social worker or to a control group. The 5-year analysis showed a continuing positive effect on appointment-keeping, weight control and blood-pressure control in the intervention groups. The all-cause life table mortality rate was 57.3% less for the intervention group than for the control group and the hypertension-related mortality rate was 53.2% less. The results from this longitudinal study provide evidence to support the use of adherence-enhancing interventions in patients with hypertension.
Another study used an educational programme to emphasize the importance of proper treatment. In the intervention groups, the systolic and diastolic blood pressure of both men and women decreased despite the 5-year increase in age; moreover, hypertension was better controlled after the programme (24.8% baseline; 39.7% at the end of the study), and substantial decreases in deaths due to cardiovascular disease were reported (18).
Another intervention that has shown promising results is home recording of blood pressure. For example, one study showed that in patients who initially showed poor compliance, there was an increase in compliance from 0 to 70% after self-measuring of blood pressure was introduced. The authors concluded that self-recording of blood pressure may be of value in patients with unsatisfactory blood-pressure responses in whom poor compliance is suspected (19).
Other studies have shown that care of patients by specially trained nurses resulted in increased adherence (20-22) and compelling evidence for the efficacy of brief, nurse-administered behavioural counselling comes from a study of 883 patients of physicians in Great Britain (21). Another study also showed that adherence to hypertension therapy would benefit from intervention by nurses (22).
Finally, Bogden et al. (23) tested the effect of physicians and pharmacists working together as a team on patients with uncontrolled hypertension. In a randomized, controlled trial, 95 adult patients with hypertension (more than twice as many patients in the intervention group as in the control group) attained blood pressure control.