Smartphone Apps for BP Popular, Useful, but Unvalidated

January 05, 2015

BOSTON, MA — A new review of smartphone-based applications for the self-management of hypertension suggests that there is a need for greater oversight, particularly for the popular apps that measure an individual's blood pressure[1].

Although most of the smartphone-based apps simply record, track, and analyze blood pressure over time, as well as provide feedback and general information about hypertension, the few apps that use the phone's camera to measure blood pressure without a cuff have not been validated, report investigators.

"Despite the advantages of mobile health technology, our study underscores a need for caution among patients and healthcare personnel," write lead investigator Dr Nilay Kumar (Harvard Medical School, Boston, MA) and colleagues in their review, published online December 11, 2014 in the Journal of the American Society of Hypertension.

In their analysis of 107 mobile health applications designed for the management of hypertension, they found that none made for the Apple iPhone were capable of measuring blood pressure. Of the 50 apps available for Google Android, seven transformed it into a medical device. These Android apps have been downloaded as many as 2.4 million times and received high consumer ratings.

"This highlights the popularity of these apps among consumers and a growing market for smartphone-based blood-pressure–measurement devices," state the researchers. "However, none of these apps were approved as measuring devices by the US Food and Drug Administration and did not have documentation of validation against a gold standard in patients with hypertension."

In fact, just 2.8% of the apps designed for the Apple iPhone or for Google Android had any documented involvement of a healthcare agency, such as a university or professional organization.

However, researchers say the results are encouraging, as most of the hypertension apps help individuals monitor various physiologic parameters, such as blood pressure and heart rate, and change their lifestyle through diet and exercise, as well as remind patients to take their medications.

Of the 107 apps, 72% were designed as tracking devices. Of these tracking apps, most were capable of tracking blood pressure and heart rate, 27% were capable of tracking weight/body-mass index, and a few were also capable of tracking salt intake (2.8%) and daily calories (4.6%). Nearly two-thirds of the tracking apps could analyze trends in blood pressure and heart rate and provide feedback based on the findings. Approximately 40% of the apps could directly export data to a physician.

"These attributes of smartphone apps can empower patients with accurate medical information, provide tools to promote self-management, and encourage greater participation in medical decision making," according to the investigators.

In an editorial published December 23 in the same journal[2], Dr Beverley Green (Group Health Cooperative and Research Institute, Seattle, WA) says the emergence of mobile health apps can help patients and their families be more involved in care and notes that many patients already wear activity trackers, fitness monitors, and smart watches that have the potential to transfer data to their electronic health records for physician feedback. "Managing these data will be challenging, but will provide new opportunities to change the way care is provided," she writes.

If a smartphone can be transformed into a mobile health device capable of accurately measuring blood pressure, it would make it "possible for billions of people to regularly check their blood-pressure status" and potentially be an important tool for improving control. At this time, though, none of the apps studied can promote accuracy as a feature because they have not been validated by approved protocols by organizations, such as the US Association for Advancement of Medical Instrumentation.

"Even if smartphones do not pass muster as blood-pressure–measuring devices, hypertension patients might appreciate other app features such as tracking and showing trends in blood-pressure data transferred from other devices, providing medication lists and reminders (eg, alarm reminders to take medications), monitoring physical activity, and sharing data with healthcare providers," writes Green.

The authors and editorialist report no relevant financial relationships.


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