Home blood pressure monitoring using an electronic sphygmomanometerAcceptability, comparability and effects on the diagnosis and management of hypertension

Background: The recent development of reliable, economic, semiautomatic electronic blood pressure monitors provides an opportunity for GPs to monitor blood pressure outside the surgery environment. Because office measurements fail to define those patients with whitecoat hypertension and whitecoat effect, we are currently overdiagnosing hypertension.Objectives: To examine the comparability of the electronic sphygmomanometer (Omron HEM 705CP) with a standard mercury sphygmomanometer. To assess the prevalence of whitecoat hypertension and whitecoat effect in general practice and the effect of these diagnoses on the subsequent management of hypertension.Method: 87 consecutive patients with established or suspected hypertension were recruited over a six-month period. Average home readings were compared with average office readings to determine prevalence of whitecoat hypertension and whitecoat effect. Simultaneous electronic and mercury readings allowed evaluation of the electronic monitor throughout the study period. A patient questionnaire assessed the acceptability of the monitor and home blood pressure measurement. A GP questionnaire assessed the effect on blood pressure management.Results: Patients were generally quite happy with the monitor. The simultaneous electronic/mercury readings showed good comparability. Home blood pressure was significantly lower than office blood pressure. 24% (21 patients) had a significant element of whitecoat effect (>20/10 mmHg) and 6% (5 patients) had whitecoat hypertension. At the end of the study, 37% (32 patients) were on less medications than if they had been managed based on office blood pressure.Conclusions: This study indicates that home blood pressure monitoring can distinguish sustained hypertension from office hypertension and thus reduce overdiagnosis and overtreatment of hypertension.