How do GPs really measure blood pressure? Adherence to hypertension guidelines in practice: results from a patient survey.

Problem

Hypertension guidelines recommend repeat measurement of blood pressure (BP) and the use of confirmatory out of office measurements when initial clinic readings are high. However, it is unclear how often these guidelines are followed in practice, if behaviour differs between general practitioners (GPs) or nurses, or if guidelines are more likely to be followed when treating specific patient groups. We sought to determine to what extent BP measurement guidance is followed during routine practice through a patient survey.

Approach

An online survey was advertised to members of several charities and patient research groups from July 2015. Respondents were asked to provide basic demographic / health data and to recall if and how their BP was measured during their last appointment. Respondents were also asked to take part in a follow-up survey after their next appointment, and were informed this would capture more in-depth data about their BP measurement. Preliminary data from the first survey were summarized by means/proportions with 95% confidence intervals.

Findings

A total of 2,283 users visited the initial survey site during the study period of which 709 (31.1%) completed the first survey and had complete data. Respondents had a mean (sd) age of 57.3 (13.2) years, 48.8% were male and 55.0% were hypertensive. At their last appointment, BP was measured once, twice or 3 or more times in 274 (59.7%), 136 (29.6%) and 49 (10.7%) people respectively and 190 people provided a BP reading.

Mean systolic BP was higher in those with who had their BP measured multiple times (1 reading mean=131.4 mm Hg, 95%CI [128.1 to 134.6] and 2 reading mean=140.1 mm Hg, 95% CI [135.8 to 144.4]) and people with high BP (>140/90 mm Hg) were more likely to be asked to monitor their BP at home (29.6 % vs. 16.8%, p=0.038). The proportion of people who had their BP measured two or more times was similar when BP was measured by a GP or nurse (44.0% vs. 38.1%, p=0.21). Hypertensives were more likely to have had their BP measured in both arms during any appointment previously but overall proportions were low (17.4% vs. 6.6%, p<0.001). Hypertensives not yet on medication were also more likely to be asked to measure their BP at home, compared to those already on medication (29.1% vs. 16.7%, p=0.028).

Consequences

BP measurement guidelines appear to be followed in many cases, with more measurements made in those with high clinic readings and those who may be considered for antihypertensive treatment. Behaviour of GPs and nurses is similar, indicating comparable levels of awareness and time to carry out additional readings. However, adherence to some specific recommendations remains low and could be improved. Further insights will be gained from the follow-up survey.