Mobile health applications for a Smartphone or tablet seem like a welcome addition to the ever-changing world of medicine — they cut down on costs, hospital visits, and provide up-to-date medical information at the touch of your fingertips, but they have their detractors, too.

A recent study presented at the American Heart Association's Epidemiology and Lifestyle meeting raises questions regarding the accuracy of a once-popular healthcare app. The Instant Blood Pressure app is no longer available for purchase in the app store, however, over 100,000 copies of the app were downloaded for $4.99 a pop and are still functional on Smartphones. Researchers from the Johns Hopkins School of Medicine found that the app failed to recognize high blood pressure measurements in eight out of 10 patients.

"We think there is definitely a role for smartphone technology in health care, 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," said Dr. Timothy B. Plante, a fellow in the Division of General Internal Medicine at Johns Hopkins, in a statement.

Plante and his colleagues recruited 85 adult patients and staff members from health clinics in the Johns Hopkins Medicine network. Each volunteer was asked to self-report any factors that could influence their blood pressure, including body mass measurements as well as race and ethnicity. While researchers gathered resting blood pressure measurements twice using a reliable automated blood pressure monitor, participants gathered their own readings twice using the Instant Blood Pressure app.

Not only were the blood pressure measurements taken by the app deemed inaccurate, they were dangerously inaccurate. Nearly 80 percent of participants with clinically high blood pressure at 140/90 millimeters of mercury or above, according to the automated blood pressure monitor, received a normal blood pressure reading from the app. Instead of gathering a true blood pressure measurement, the app simply provides a population-based estimate based on age, sex, height, weight, and heart rate.

"Because this app does such a terrible job measuring blood pressure, 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," Plate added. "The next big step in health care is to further engage folks in their own care and motivate them to reduce risks associated with diseases like high blood pressure. But care must be taken to make sure they get the accurate ways to do that."

The Johns Hopkins research team recommends the tried-and-true method for measuring blood pressure — inflating a cuff wrapped around the brachial artery in the arm to indicate the force of blood flowing when the heart is beating and at rest. Measurements are gathered by either a trained medical professional or a machine that “listens” to the sounds that are produced from the brachial artery as blood flows from the cuff at different levels of pressure.

“We were skeptical that even very talented people could design an app that could accurately measure blood pressure in such a different way," said Dr. Seth Martin, a fellow in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine. "Because of the absence of any rigorous scientific testing, there was no evidence that it worked or didn't work."

In spite of the disappointing results of this study, researchers are confident that technological improvements can be made to improve upon the accuracy and practicality of apps like Instant Blood Pressure. Back in 2013, the U.S. Food and Drug Administration announced that it would start to regulate healthcare apps based on their ability to act as a diagnostic tool.

Source: Urrea B, Martin S, Plante T, at al. Validation of the Instant Blood Pressure Smartphone App. JAMA Internal Medicine. 2016.