Blood pressure app downloaded 100,000 times proves inaccurate, study shows

Blood pressure

flickr photo by Waifer X shared under a Creative Commons (BY) license

A blood pressure app that has been downloaded over 100,000 has been shown to be unreliable, according to a study by John Hopkins University, with just a 20% accuracy rate.

The ‘Instant Blood Pressure’ app claimed to provide an accurate and instant measure of blood pressure when the user placed a SMART phone to their chest.

Results of a study of 85 volunteers using the app under the guidance of health professionals showed that the app missed the warning signs in eight out of ten patients who had high blood pressure. 

The Instant Blood Pressure app is no longer available to buy and download. According to researchers, the app will still be functioning on the 100,000 users phones who have downloaded it before it was made unavailable.

Brachial artery is best

The traditional method of measuring blood pressure is by inflating a blow-up cuff around the brachial artery (in the arm) to measure the force of blood flow. This is done when the heart is beating and at rest. Health professionals listen to the ‘Korotkoff sounds’, first discovered in 1905 by the Russian physician Dr. Nikolai Korotkoff.

To test the Instant Blood Pressure app’s accuracy in measuring blood pressure,  85 adult volunteers across the spectrum in terms of body mass, races and ethnicities. were recruited. Each participant had their resting blood pressure measured twice on the same day using a reliable automatic blood pressure monitor. Participants were also required to use the Instant Blood Pressure app to measure their own blood pressure twice on the same day.


Nearly 80 percent of participants with clinically high blood pressure (defined as 140/90 millimeters of mercury+) as recorded by the automated blood pressure monitor showed normal blood pressure when measured by the app.

According to John Hopkins media, the authors of the paper say that it is unclear how the app arrives at a blood pressure number.

Researchers note that health monitoring apps are increasing in popularity, many have the potential to improve health by putting personalised medical information literally ‘in the hands of patients through cellphones.’ However, it is important that the information given is accurate.


“We think there is definitely a role for smartphone technology in health care, but the results of our study speak to the need for scientific validation and regulation of these apps before they reach consumers”

Timothy B. Plante, M.D., a fellow in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine.


Popular blood pressure app misses the mark, John Hopkins Medicine.

What you should know: The Plante et al. study (the app builder’s argue back).