Different protocols can affect BP readings
Different protocols for measuring blood pressure during a visit have significant and clinically relevant effects on readings, a new study shows.
Dutch researchers tested several strategies for measuring blood pressure as used in large clinical trials or recommended in guidelines in 223 patients with diabetes.
They found blood pressure was 5.7/2.8mmHg higher when taking the mean of two readings than the mean of the last three of four as was done in the 'gold standard' UKPDS study.
Systolic blood pressure was also significantly higher with one reading than two, according to the study, published online in Family Practice.
The researchers warned BP could be overestimated in a significant number of patients if just one or two readings were taken.
Dr Tom Marshall, senior lecturer in the department of public health and epidemiology, University of Birmingham, said the study showed the difficulties of measuring BP: 'It's one of the reasons why we should base treatment on CVD risk rather than one risk factor alone.'