Most patients with diagnosed high blood pressure (also called hypertension) know that regular use of prescribed medication can lower blood pressure and the risk of cardiovascular disease. Many of them, however, don’t maintain the regimen of medication recommended by their physicians to control their blood pressure.
One new strategy to help people with high blood pressure manage the condition is through the use of smartphones. At least 200 smartphone applications are now available to help people monitor and control high blood pressure. These apps offer education, tracking functions, reminders for medication usage, and even the ability to take blood pressure readings.
Smartphone users, however, should approach these apps with caution. Despite their popularity, many apps that claim to measure blood pressure and heart rate have no medical validity.
Despite their shortcomings, mobile health programs have been effective in helping people with high blood pressure remember to take their medication and access information about dietary changes, which has enabled them to control their blood pressure.
Medical apps have been proliferating because of the growing popularity of smartphones. A Pew Research Center survey showed that 52 percent of smartphone owners use their devices to access mobile health apps and websites. By 2018, the number of mobile health users is expected to rise to 1.7 billion people, constituting nearly a quarter of the world’s population.
Questions about validity
A 2015 study published in the Journal of the American Society of Hypertension analyzed 107 mobile apps relating to high blood pressure.
The researchers found that 72 percent of the apps could track indicators such as a patient’s blood pressure, heart rate, salt and calorie intake, and body mass index. A total of 37 percent offered general information on high blood pressure, and 22 percent provided tools to help patients take their medications via smartphone features such as notifications or alarms. Only 3 percent of the 107 apps were developed by a healthcare agency.
While the researchers acknowledged that these types of platforms can be beneficial, they called into question apps claiming to convert a smartphone into a medical device. The study found that 14 percent of hypertension apps available on Google Play claimed to be able to measure blood pressure and heart rate when the user’s finger was placed on the phone screen or camera—but none had any documentation of medical validity.
Although these apps made medical claims without providing proof, they received up to 2.4 million downloads by smartphone users, the highest number of downloads among all the apps dealing with high blood pressure.
Another study of apps that address high blood pressure found that those claiming to measure blood pressure can give highly inaccurate readings.
This study, reported in the May 16, 2016 issue of JAMA Internal Medicine, followed 85 people who had their blood pressure measured by the Instant Blood Pressure app, which was available for more than a year before it was taken off the market in 2015. The iPhone app, which cost $4.99 to download, required users to place the top edge of the smartphone on the left side of their chest and their index finger over the device’s camera lens.
When the study participants measured their blood pressure, using both a traditional instrument with an inflatable cuff and the Instant Blood Pressure app, there were wide variations in the readings.
The results showed that the app underestimated higher blood pressure. As a result, 78 percent of people with high blood pressure who used the app were falsely led to believe that their blood pressure was not in the hypertensive range.
The app is no longer available, but the researchers pointed out that it is still installed on a large number of iPhones and people may still be using it to measure blood pressure and regulate their medication. The researchers also noted that other apps using similar methods to assess blood pressure are still on the market.
Some are useful
While concerns have been raised about the validity of apps claiming to measure blood pressure, other apps have been shown to help patients manage high blood pressure by sending text messages as reminders to take their medication.
One study tested patients who used both a cellular-connected electronic medication tray, which sent them reminders to take medications, and smartphone texts that advised them to take their blood pressure at home with a wireless Bluetooth monitor. The program, called Smartphone Medication Adherence Stops Hypertension (SMASH), was designed for and tested on Hispanics, a group that has a high rate of hypertension.
The 2013 study, published in Smart Homecare Technology and TeleHealth, found that over three months, the 10 patients who participated in the trial all had systolic blood pressure that declined by 47.2 mm Hg, compared to a standard care group, which had a drop of 12 mm Hg. The patients in the SMASH group reported that the program helped them take their medications on time and improved their health.
Regulating medical apps
Patients who want to use a smartphone app to control their high blood pressure should first find out if the app is considered a medical device used to diagnose or treat disease, which would require U.S. Food and Drug Administration (FDA) approval. Since 2013, the FDA has regulated three types of mobile medical apps:
• Apps that turn a smartphone or tablet into a medical device, such as an app that measures blood pressure.
• Apps that are used as an accessory, allowing healthcare professionals to make a diagnosis with images from a mobile device.
• Apps that act as an extension to another medical device by displaying, storing, or transmitting patient data.
The FDA does not regulate apps intended only for general wellness. Here are examples of apps that have been cleared by the FDA.
Mobile health technology has been shown to reduce blood pressure when apps are used to keep track of heart rate and blood pressure, promote regular usage of medication, and provide information about dietary changes to reduce high blood pressure.
As the number of medical apps is expected to double every two to three years, medical professionals are concerned that programs claiming to measure the blood pressure of smartphone users may endanger patient safety. Until these measurement apps are tested in clinical trials and approved by the FDA, patients should rely on traditional validated blood pressure devices used by their doctors.
Medical smartphone apps can be beneficial if they encourage users to be more aware of their health. But they are not a substitute for medical evaluation.
Read more about how apps may help your health.