Measuring blood pressure in primary care: identifying 'white coat syndrome' and blood pressure device comparison

Hypertension is a major risk factor for cardiovascular disease, especially in the presence of other risk factors.1 Accurate identification of hypertension is challenging largely due to blood pressure variability in an office or clinic where most GP consultations take place. Blood pressure can be affected by several factors including measurement technique and observer bias.2

Ambulatory blood pressure monitoring (ABPM) and self-monitoring, two methods used to detect ‘white coat syndrome’ (the phenomenon whereby blood pressure measured by medical personnel is elevated above usual levels), have been shown to be more accurate in predicting end-organ damage than office readings.3,4 However, thresholds for diagnosis of hypertension with ABPM vary and guidelines recommend its use in specific circumstances only.5 The use of self-monitoring in diagnosis is unclear in terms of the number of blood pressure readings required.6 Furthermore, current cardiovascular risk assessment charts are based on office blood pressure readings, so when calculating cardiovascular risk clinicians need a reliable method of measuring office blood pressure.