A blood pressure reading app sounds promising, but a new study says that it is inaccurate. Such erratic results could confuse people with hypertension in thinking that they have normal blood pressure, even if it is dangerously high.
The Instant Blood Pressure app from AuraLife was designed to estimate blood pressure by placing the edge of the smartphone or tablet on the part of the chest where the heart is located. The user will also put the right index finger over the smartphones built-in camera lens.
The researchers from John Hopkins University found that 80 percent of patients with high blood pressure, with readings 140/90 or higher, got normal blood pressure readings when using the app. Misreading the result for about eight out of 10 people significantly puts the user's health at risk.
To test the app, the researchers recruited 85 people, more than half had a diagnosis of hypertension and nearly all of them are taking medications for the condition. They used the same standards that new blood pressure cuffs must meet to be used in hospitals and clinics.
They checked the blood pressure twice with the app and compared the average result from the two readings to the reading from a traditional blood pressure cuff.
Inaccurate Blood Pressure Measurements
The results show that the average differences between the app reading and traditional device reading were 12.4 mmHg for systolic blood pressure and 10.1 mmHg for diastolic blood pressure.
Though the app, worth $4.99, is no longer available on Google Play and the iPhone App Store, several other apps with the same purpose are still available.
"If someone with high blood pressure is using Instant Blood Pressure to follow their blood pressure at home, more times than not it's going to tell them they're fine," said Dr. Timothy Plante, the study's lead researcher.
The app measured blood pressure incorrectly and this could lead to serious harm to users by masking the true risk of complications linked to hypertension such as stroke or heart attack.
The study was published in the journal JAMA Internal Medicine.
The App Is Now Unavailable
Since its launch back in June 2014, the app became one of the 50 best-selling apps for 156 days, during which it was downloaded 950 times daily. The maker of the app removed it in July 2015 with about 148,000 downloads.
"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 Plante. "That it doesn't use a cuff is neat as folks don't generally like carrying around a bulky blood pressure monitor."
He also added that the wrong measurements, either for high or low readings, should be a cause of concern. In particular, those with hypertension, a condition known as the silent killer, could be left untreated and may lead to stroke, heart diseases, and kidney problems.
Auralife, however, posted on its website, a detailed article titled, "What You Need To Know: The Plante Et. Al. Study," in response to the aforementioned study.
"Alarmingly, it became immediately apparent that critical inaccuracies and deficiencies were present in how this study was conducted," the company said. "At Auralife, we welcome third party researchers taking an active interest in assessing our technologies. Further, we believe open discussion with researchers is important in advancing health technology."
Auralife conducted its own internal studies showing that Instant Blood Pressure app does not yet meet the performance standards, but provides only an estimate of the reading. The study by the company was based on the benchmark imposed by the ANSI/AAMI/ISO 81060-2:2013, an internationally accepted protocol for blood pressure cuff performance assessment.
The company added that the app is not a medical device and it is not intended to be used to diagnose an illness like hypertension. The app should be used for "recreational purposes only."