Featured Heart health Research

How accurate is your doctor’s blood pressure test?

Written by Katherine Nazimek

Blood pressure measurement is considered a cornerstone for the diagnosis and treatment of hypertension, but experts are questioning the accuracy of blood pressure testing conducted in doctors’ offices.

Traditionally, blood pressure tests have been conducted manually: a doctor or nurse would wrap a cuff around your upper arm, pump the cuff full of air, and release the air while listening through a stethoscope and reading the measurement on a gauge. But research over the past several decades has noted many problems with this form of testing:

“Talking with the patient, not allowing periods of rest before the readings, rapid deflation of the cuff and rounding off readings to the nearest zero have resulted in readings that are both inaccurate and inappropriately high,” says Dr. Martin Myers, a cardiologist at Sunnybrook Health Sciences Centre and a leading scientist in hypertension and blood pressure measurement.

Now, a new study published in JAMA Network and led by Myers, confirms manual measurement should be replaced with what’s known as fully automated office blood pressure (AOBP) measurement.

AOBP requires a patient to sit alone for several minutes as a computer records several blood pressure readings. These devices are similar to what you’d use for home monitoring, but are more advanced and have a built-in delay that allows a nurse or physician to initiate readings, and then leave the patient alone before any measurements are taken.

“The common cause of inaccuracy with any blood pressure measurement testing is human interaction or human error,” says Myers, “If we can remove or restrict human interaction with the test, we can improve its accuracy.”

The study also suggests AOBP measurement may effectively be taken in a community pharmacy or in physicians’ waiting rooms, as long as the patient is sitting alone and is not disturbed by medical staff.

When it comes to diagnosing hypertension, Myers says even using blood pressure monitoring devices at home can be better than testing exclusively in a medical office, provided the testing is done properly.

“If you’re at home, take your blood pressure readings twice in the morning and again in the evening for at least four days, and preferably a week,” says Myers. “These readings should be taken at about the same times each day, and not when you think your blood pressure may be particularly high or low.”

Myers adds that after a week of readings, you should take the device to your family doctor who could verify the measurements and give you a proper diagnosis.

About the author

Katherine Nazimek

Katherine Nazimek is a Communications Advisor at Sunnybrook.

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