Australian researchers have advised doctors to be wary of blood pressure measuring devices that take a reading at a patient’s wrists as they found a wide variation in readings. 

Many devices used by patients at home, including the increasingly available wearable monitors, measure blood pressure at the wrist and other locations.

Researchers from the University of Tasmania measured intra-arterial blood pressure consecutively at the brachial and radial arteries in 180 patients with a mean age of 61, undergoing coronary angiography.

“We expected to see a lot of variation in how systolic blood pressure changed from the upper arm to the wrist, but were interested to see the amount of people (14%) with what may be considered as very large differences: on average, more than 20mmHg,” lead author Dr James Sharman said.