There's an app for that medical issue. Should you use it?

Health apps are hailed for revolutionizing medicine. Just one little problem: Some of them are wildly incorrect.

Photo of instant blood pressure app in in use. Photograph by Natalie Castellino.

An instant blood pressure app in in use. Photograph by Natalie Castellino.

Can your smartphone save you a trip to the doctor’s office or to the ER? That is the premise of the $4-billion mobile health industry, with over 165,000 health apps available to download onto your phone to diagnose, manage and treat medical problems. One of the biggest sellers: Instant Blood Pressure. An app that offered a way to measure your blood pressure using only your smartphone, and required neither a doctor nor any special equipment, it cracked the top 50 sellers list on Apple’s App Store after its release in 2014, and stayed there for 156 days.

There was just one problem. The app proved to be wildly inaccurate. In a recent study, Dr. Timothy Plante and a team from Johns Hopkins University found that, on average, the app was off by 10 to 15 points when it measured people’s blood pressure. Plante also found that the app had a low sensitivity for catching high blood pressure. “It missed almost 80 per cent of hypertension readings in our population,” he tells Maclean’s. That’s a critical flaw because treating high blood pressure early can prevent complications like vision loss, kidney failure, heart attacks and stroke—and catching it is presumably why a consumer would download the $3.99 app.

AuraLife, the company behind the app, has responded by posting detailed criticisms of the study on their website. According to Ryan Archdeacon, CEO and founder of AuraLife, the app was only validated for systolic blood pressures between 102 and 158, as mentioned in the FAQ section of the company’s website. That means that the app will not produce readings outside this range, and blood pressures above or below that threshold would either yield an error message or an inaccurate value. He also stresses that Instant Blood Pressure is not a medical app and not meant to diagnose disease.

However, comments found on the App Store suggest that’s exactly what people were relying on it for. Numerous comments show that patients with hypertension, on dialysis, and with other medical problems were using the app to monitor their blood pressure and adjust medications. Instant Blood Pressure had 148,000 downloads and spawned a number of copycat apps. Given its popularity, Plante worries about how many people may be using this technology inappropriately. “There’s a big concern for public health complications from an inaccurate, widely used app,” says Plante in an interview.


But Instant Blood Pressure is not the first health app to fall short of its promises. In 2011, Pfizer sent a letter to doctors warning that its Rheumatology Calculator app was making critical mistakes when measuring disease severity in arthritis patients. In 2012, Sanofi recalled its diabetes app for miscalculating insulin doses and putting users at risk for severe blood sugar spikes and drops. And in February 2015, the Federal Trade Commission in the U.S. concluded an action against two apps that claimed they could diagnose skin cancer by analyzing a photo of a mole.

Nor is this a problem for only very specialized apps. A 2015 systematic review found that while popular fitness trackers like Fitbit and Jawbone do a good job as step counters, they generally underestimate the amount of energy you burn, and overestimate sleep time and sleep efficiency.

“Some of these apps are really impressive in idea and design, but what’s missing is a lot of good research and data to support them,” says Nathan Cortez, professor of law at Southern Methodist University. He says part of the problem is that the FDA is simply not aggressive in forcing companies to substantiate their health claims. What enforcement that does happen is led by the FTC because of false or misleading consumer advertising. For example, it was the FTC that forced brain-training game maker Lumosity to drop claims that using its product could help prevent Alzheimer’s disease and dementia. Lumosity also had to pay a $2 million settlement to the U.S. government.

Along the way, medical apps also generally fall outside governmental regulation when it comes to data security. A study published last month in the Journal of the American Medical Association found that over three-quarters of the 271 diabetes apps studied by researchers shared users’ data with third-party websites and placed tracking cookies on users’ phones. Worse, more than half did not disclose the fact that they were sharing information. The authors of the study warn that while “patients might mistakenly believe that health information entered into an app is private . . . that generally is not the case.” Many apps, once downloaded, also outlive the companies that built them. Of the diabetes apps that researchers looked at, 60 became unavailable within six months. Despite disappearing from the market, they can remain on users’ phones unless actively deleted. The Instant Blood Pressure app was removed from the App Store in July 2015 for undisclosed reasons and it remains unclear how many phones may still have working copies of the app installed on them. AuraLife CEO Archdeacon declined to comment for this article as to the reason for its removal.

Some in Congress worry that more regulation would stifle innovation. But Cortez sees it differently. He knows both patients and physicians see the potential these apps provide in terms of convenience for patients. But he worries that without proper oversight and control, we won’t be able to trust the information medical apps are giving us. In the long term, he believes both the public and the industry would be better off if the FDA required apps to substantiate their claims.

In Canada, the medical devices bureau of Health Canada regulates and approves the sale of medical apps. By email, Health Canada explained that it evaluates apps using a risk-based strategy; those judged to be low-risk do not need a medical device licence, as long as the seller is a licensed company. It also provides a website,, listing all licensed apps. Instant Blood Pressure is not on the list, but was still available to Canadian consumers.

“I would imagine that a lot of the apps Canadian consumers may have on their phones haven’t had their validity assessed by Health Canada,” says Matthew Herder, associate professor of law and medicine at Dalhousie University. He says the big problem is that for too long resources have been taken away from the people in charge of enforcement. “It’s really not a question of whether we have sufficient means in law to address the problem. It’s whether we have the will to enforce the law we have.” Health Canada generally uses a “co-operative approach” when it comes to enforcement. This usually involves sending offending companies a compliance letter asking them to voluntarily conform to the law. That might mean changing labelling, or removing offending lines from their advertising. More serious actions like fines and court injunctions to stop sales or advertising are rarely used options.

And yet, despite the many problems, nearly everyone believes that mobile health apps have the power to transform how we practise medicine. “I like these things,” Cortez admits, “I have an Apple Watch and a phone full of apps. My interest is in trying to create a framework so these things truly meet their potential down the road. I just worry we’re going to be flooded with products that don’t work.”