Popular blood pressure app found highly inaccurate: study

A popular smartphone app, which measures blood pressure simply by placing a cellphone on the chest with a finger over the built-in camera lens, delivered inaccurate results in eight out of 10 patients, potentially putting users' health at risk, a study said Wednesday.

The findings, published in the U.S. journal JAMA Internal Medicine, highlighted an urgent need for greater oversight in the development of medical apps that enabled patients to track their own health status.

"We think there is definitely a role for smartphone technology in health care," study author Timothy Plante of the Johns Hopkins University School of Medicine said in a statement.

"But because of the significant risk of harm to users who get inaccurate information, the results of our study speak to the need for scientific validation and regulation of these apps before they reach consumers," Plante said.

The Instant Blood Pressure app, which was released in June 2014 and removed in July 2015 for reasons that are unclear, spent 156 days as one of the top 50 best-selling iPhone apps.

Although the 4.99-U.S.-dollar app is no longer available for purchase, it was downloaded more than 100,000 times and is still functional on phones, the researchers said.

In the new study, the researchers recruited 85 adult volunteers, with more than half self-reporting hypertension and 91 percent of these participants reported taking antihypertensive medications.

Each participant had his or her resting blood pressure measured twice using a reliable automated blood pressure monitor commonly used in research studies to avoid measurer variation or error. Participants also used the app to measure their own blood pressure twice on the same day.

Results showed that blood pressures measurements from the app were overwhelmingly inaccurate. Close to 80 percent of those with clinically high blood pressure, defined as 140/90 millimeters of mercury or above, measured by the automated blood pressure monitor showed normal blood pressure with the app.

"Because this app does such a terrible job measuring blood pressure," said Plante, "it could lead to irreparable harm by masking the true risk of heart attacks and strokes in people who rely on the accuracy of this information."

Though the results of this study were discouraging, they said improvements in the technology could make blood pressure measurement apps accurate and useful in the future.

"From a public health perspective, our study supports partnership of app developers, distributors and regulatory bodies to set and follow standards for safe, validated mHealth [mobile health] technologies," their research letter concluded. Endit