A popular mobile health (mHealth) app for a smartphone that measures blood pressure (BP) was found highly inaccurate compared with standard sphygmomanometer readings, according to a research letter published in JAMA Internal Medicine.1
The Instant Blood Pressure app (IBP) from AuraLife was available from June 5, 2014, until July 30, 2015. In that time, the app was among the top 50 best-selling iPhone apps for 156 days with approximately 950 copies sold on each of those days. However, this and other similar smartphone apps have not been validated in clinical studies.
Researchers at Johns Hopkins University School of Medicine investigated the accuracy and precision of IBP using a protocol based on national guidelines. Researchers were trained on use of the app per the manufacturer guidelines, and trained to follow a standard protocol using calibrated, validated automated sphygmomanometers for standard BP measurements.
Written informed consent was obtained from 101 of 105 prescreened persons, with and without hypertension. Data for 16 participants was discarded for reasons defined in prespecified dropping rules. Of the remaining 85 participants, 44 (52%) were women, mean age (SD) was 56.6 (16.3) years, body mass index was 27.8 (5.8). Forty-five (53%) participants reported having hypertension, 41 (91%) of whom reported taking antihypertensive medications.
The difference between IBP and standard measurements were 12.4 (SD 10.5) mm Hg for systolic BP and 10.1 (SD 8.1) mm Hg for diastolic BP. The researchers found that higher BP measures were underestimated and lower BP measures were overestimated.
Systolic BP readings with the IBP app were within 5 mm Hg of the standard measurement 24% of the time, within 10 mm Hg 44% of the time, and within 15 mm Hg 59% of the time; diastolic BP readings were within 55 mm Hg of the standard measurement 26% of the time, within 10 mm Hg 48% of the time, and 15 mm Hg 70% of the time. These measurements correlated with the lowest possible accuracy grade in all categories by British Hypertensive Society scoring.
These study findings demonstrate that the mHealth app produced highly inaccurate readings, which could give more than three-fourths (77.5%) of persons with hypertensive BP levels false reassurance that their BP is in the nonhypertensive range.
“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 technologies,” the researchers conclude.
1. Plante TB, Urrea B, MacFarlane ZT, et al. Validation of the instant blood pressure smartphone app [published online ahead of print March 2, 2016]. JAMA Intern Med. doi:10.1001/jamainternmed.2016.0157.