New Study Finds Blood Pressure Machines Most Accurate Way of Taking Blood Pressure

Feb 19, 2019

Having your blood pressure taken in a family doctor’s office is a routine part of care for most people. Although high blood pressure (or hypertension) is usually invisible because it does not have symptoms, the risks can be very serious. Untreated high blood pressure can lead to heart disease, stroke, kidney failure, and other health issues.

A recent study led by Dr. Michelle Greiver at the University of Toronto Department of Family and Community Medicine (DFCM) found that the numerical results of blood pressure readings completed in medical offices are sometimes rounded down.

“It’s an interesting insight into human behaviour, actually,” says Dr. Greiver, a family medicine researcher and Director of the University of Toronto Practice-Based Research Network (UTOPIAN), part of DFCM. “We prefer to round down and use even numbers, particularly zero. While that might not seem like a big deal – rounding from 137 to 135 - it is important to the health of our patients that we have measured their blood pressure accurately; inaccuracies may lead to errors in the diagnosis and treatment of hypertension.”

Dr. Greiver and her colleagues examined the data from 707,221 patients in Canada and 1,558,471 patients in the UK and found that when offices invested in automated blood pressure machines, the number of blood pressure readings ending in the number zero decreased significantly. Both countries had similar results.

The research suggests that automated blood pressure machines, which record the numeric values of blood pressure three to six times (the initial reading is discarded, and the remaining readings are averaged) are far more accurate than having a doctor or nurse take the blood pressure manually.

In fact, researchers further found that clinics that had more blood pressure readings ending in zero – likely because they were not using automated blood pressure machines regularly - had more patients who had strokes, heart attacks and heart disease.

“There have been concerns for a long time in the medical community that blood pressure numbers haven’t been accurate,” says Dr. Greiver. “Based on this research, I think it is wise for physicians to invest in automated blood pressure machines and use them when they can.  Controlling blood pressure is important for patients, and it should be measured properly—with an accurate machine.”

To access the full study, please click here .