Antihypertensive drug treatment: A comparison of usual care with self blood pressure measurement

Blood pressure self-measurement is increasing in most communities and yet its role in the management of hypertension is poorly understood. This study was devised to evaluate the behaviour of doctors in general practice when treating patients with poorly controlled essential hypertension who use self-measurement. Patients, most of whom were already taking antihypertensive medications were commenced on perindopril or indapamide at their doctor's discretion and were randomly allocated to self-measurement (SM) using an OMRON HEM706 oscillometric device or a continuation of their usual care (UC) over an 3-week period. This was an observational study without any specific or set treatment goals for the doctor to follow. Sixty of 62 subjects completed the study and the two groups were equally matched for age, body mass index, gender, and blood pressure (BP). While additional perindopril or indapamide produced a significant fall in BP in both groups over the study period, the systolic pressure remained significantly higher in the SM group (sitting 148 +/- 3 compared with 142 +/- 3; 145 +/- 3 compared with 138 +/- 3 mm Hg respectively; P < 0.05). Twenty-four hour and daytime ambulatory monitor systolic pressures were also significantly higher in the SM group. Differences in diastolic BP were not statistically significant. Furthermore, SM patients were less likely to have their medications increased and more likely to have them reduced or ceased. Doctors and patients found self-measurement convenient and useful. This study suggests that doctors prescribing decisions are influenced by evidence from self-measurement of BP with consequential increases in office BP related to reduced drug use. While self-BP measurement can offer reassurance about adequacy of control when away from a physicians office, our best evidence of understanding target blood pressures comes from large randomised studies using office blood pressures as an end-point. There is an urgent need for further study to provide arbitration between self-measurement and office blood pressures although each measurement must contribute to the management of hypertension.