Replacing the mercury manometer with an oscillometric device in a hypertension clinic: implications for clinical decision making.

Oscillometric devices are being widely used for ambulatory, home and office blood pressure (BP) measurement, and several of them have been validated using established protocols. This cross-sectional study assessed the impact on antihypertensive treatment decisions of replacing the mercury sphygmomanometer by a validated oscillometric device. Consecutive subjects attending a hypertension clinic had triplicate simultaneous same-arm BP measurements using a mercury sphygmomanometer and a validated professional oscillometric device. For each device, uncontrolled hypertension was defined as average BP ≥140/90 mm Hg (systolic/diastolic). A total of 5108 simultaneous BP measurements were obtained from 763 subjects in 1717 clinic visits. In 24% of all visits, the mercury and the oscillometric BP measurements led to different conclusion regarding the diagnosis of uncontrolled hypertension. In 4.9% of the visits, the diagnostic disagreement was considered as 'clinically important' (BP exceeding the diagnostic threshold by >5 mm Hg). These data suggest that the replacement of the mercury sphygmomanometer by a validated professional oscillometric device will result into different treatment decisions in about 5% of the cases. Therefore, and because of the known problems when using mercury devices and the auscultatory technique in clinical practise, the oscillometric devices are regarded as reliable alternatives to the mercury sphygmomanometer for office use.