[Green study: quality of blood pressure measurement by general practitioners]

Diagnosis and management of hypertension is based on blood pressure (BP), as measured by auscultatory method. However, the devices are rarely checked making the quality of the measures doubtful.

To compare BP measured according to the WHO recommendations using 2 different devices: the mercury or aneroid sphygmomanometer used by the physician and a SECURUS manometer that has been calibrated just before the implementation of the study.

This is a randomised study performed with 1,336 French general practitioners (GP). Each GP received a calibrated SECURUS before the start of the study and was asked to include 2 treated hypertensive patients and one newly diagnosed patient. BP was measured 3 times with each device at 2 different visits. The devices were used in a random order: the order, at the 1st visit, was always the same for all the patients for a given GP. At the second visit the order of the devices was reversed. Patients were classified as normal (BP < 140/90 mm Hg) or high BP with each device at each visit.

3,992 patients were included in the study (2,751 treated hypertensive patients). SECURUS BP measures were rounded up to 0 or 5 by 69% of the GPs and BPs with their own device by 77% of the GPs. A difference between the 2 devices > 5 mmHg was observed in nearly 10% of the GPs for SBP and 4% of the GPs for DBP. At the second visit, 13% of the treated hypertensive patients and 12% of the newly diagnosed patients and in whom no antihypertensive drug treatment has been introduced were not classified as having normal or high BP value in the same way by the 2 devices.

This study confirms the results of a previous pilot study and emphasises the need of BP measurements respecting the guidelines in clinical practice, because of the possible impact on patient care and related costs.