Blood pressure measurement in the community: do guidelines help?

The measurement of blood pressure (BP) is a crucial part of clinical assessment and hypertension management, and is commonly performed inaccurately despite the publication of National and International consensus guidelines for its measurement. There have been no previous reports on the self-reported knowledge-base of General Practitioners (GPs) and Practice Nurses (PNs) with regard to BP measurement. A postal questionnaire survey was conducted of 831 community-based practitioners (550 GPs and 281 PNs) in north west London. The overall response rate was 61%. Previous education in BP measurement was recorded in 87% of the GPs and 95% of the nurses. Precision factors were recorded for the GPs and nurses respectively including rounding up or down (GP 67%, PNs 48%), routine use of diastolic phase V (GP 63%, PNs 70%), reading the BP to the nearest 2 mm mercury (GP 54%, PNs 70%) and failure to use a large BP cuff in the past 4 weeks (GP 33%, PNs 26%). Only 12% of the GPs and 19% of the nurses were able to name the source of the published guidelines. Overall the nurses had a statistically significantly greater knowledge base than the GPs, and both community groups had a greater knowledge for core questions than hospital practitioners from two previous surveys. Knowledge of a guideline source was associated with improved self-reported BP technique. There was a difference between reading and recording accuracy which deserves further study. These results show that there are important gaps in the knowledge of community practitioners with regard to the technique of BP measurement.