A blood pressure app downloaded by tens of thousands of people before sales halted last year gave many patients with hypertension the false impression that their vital signs were normal when in reality they were dangerously high, a U.S. study suggests.
The app in question, Instant Blood Pressure from AuraLife, was designed to estimate blood pressure by placing the top edge of a smartphone on the left side of the chest and holding the right index finger over the camera on the device.
But approximately four out of every five people with hypertension got inaccurate readings from the app that suggested their blood pressure was in a normal range when it was actually high, the study found.
"If Instant Blood Pressure worked, it would be a revolutionary new technology that would allow for low-cost screening and management of hypertension among smartphone users," said lead study author Dr. Timothy Plante of Johns Hopkins University in Baltimore.
"That it doesn't use a cuff is neat as folks don't generally like carrying around a bulky blood pressure monitor," Plante added by email. "Inaccurate measurements for high or low readings are concerning, however. Hypertension is known as the silent killer as it has an asymptomatic course that leads to serious conditions like heart disease, kidney disease, and stroke."
At least 148,000 copies of the app were sold for $4.99 from June 2014 to July 2015, Plante and colleagues estimate in JAMA Cardiology.To test how well the app worked, the research team used the same standards new blood pressure cuffs must meet to win U.S. regulatory approval for use in doctors' offices.