Diagnosed by App: Medical Testing in the Palm of Your Hand

The shift to in-home medical testing through smartphone apps is expected to save patients time in receiving certain kinds of diagnoses, but raises some privacy concerns.

(© Destina/Adobe and Unsplash)


Urinary tract infections aren't life-threatening, but they can be excruciatingly painful and debilitating.

"Overnight, I'd be gripped by this searing pain and I can barely walk," says Ling Koh, a Los Angeles-based bioengineer. But short of going to the ER or urgent care, she'd have to suffer for a few days until she could get in to see her family doctor for an antibiotic prescription.

Smartphones are now able to do on-the-spot diagnostic tests that were previously only able to be performed in a lab.

No longer. Koh, who works for Scanwell Health, was instrumental in the development of the company's smartphone app that is FDA-cleared for urinary tract infection screening. It allows someone to test urine at home using a paper test strip — the same one used by doctors in ERs and labs. The phone app reads a scan card from the test kit that can analyze what's on the strip and then connect the patient to a physician who can make a virtual diagnosis.

Test strips cost $15 for a three-pack and consultation with a doc is about the same as an average co-pay -- $25, and the app matches the quality of clinical laboratory tests, according to the company. Right now, you can get a referral to a telehealth visit with a doctor in California and get a prescription. A national rollout is in the works within the next couple of months.

"It's so easy to use them at home and eliminate the inefficiencies in the process," says Koh. "A telemedicine doctor can look at the test results and prescribe directly to the pharmacy instead of women waiting at home, miserable, and crying in the bathtub."

Scanwell is now involved in an ongoing National Institutes of Health- sponsored study of chronic kidney disease to test a version of the app to identify patients who have the disease, which affects more than 30 million Americans. "Because kidney disease has virtually no symptoms, by the time people realize they're sick, their illness is advanced and they're ready for dialysis," says Koh. "If we can catch it sooner, early intervention can help them avoid kidney failure."

Smartphones have changed society — and now they may change medical care, too. Thanks to the incredible processing capabilities of our smartphones, which come equipped with a camera, access to the internet and are thousands of times faster than the 1960s era NASA computers that ran the Apollo Moon Mission, these pocket-sized powerhouses have become an invaluable tool for managing our health and are even able to do on-the-spot diagnostic tests that were previously only able to be performed in a lab.

This shift to in-home testing is the wave of the future, promising to ease some of the medical care bottlenecks in which patients can have two- to three-week waits to see their family doctors and lift some of the burdens on overworked physicians.

"This is really the democratization of medicine because a lot of the things we used to rely on doctors, hospitals, or labs to do we'll be able to do ourselves," says Dr. Eric Topol, an eminent cardiologist and digital health pioneer at the Scripps Clinic and Research Institute in La Jolla.

But troubling questions remain. Aside from the obvious convenience, are these tests truly as accurate as ones in a doctor's office? And with all this medical information stored and collected by smartphones, will privacy be sacrificed? Will friends, family members, and employers suddenly have access to personal medical information we'd rather keep to ourselves?

The range of what these DIY health care apps can do is mind-boggling, and even more complex tests are on the way.

"I'm really worried about that because we've let our guard down," says Topol. "Data stored on servers is a target for cyber thieves — and data is being breached, hacked, brokered, and sold, and we're complacent."

Still, the apps have come a long way since 2011 when Topol whipped out an experimental smartphone electro-cardiogram that he had been testing on his patients when a fellow passenger on a flight from Washington D.C. was seized with severe chest pains. At 35,000 feet in the air, the app, which uses fingertip sensors to detect heart rate, showed the man was having a heart attack. After an emergency landing, the passenger was rushed to the closest hospital and survived. These days, even the Apple Watch has an FDA-approved app that can monitor your electro-cardiogram readings.

The range of what these DIY health care apps can do is mind-boggling, and even more complex tests are on the way. Phone apps can now monitor sleep quality to detect sleep apnea, blood pressure, weight and temperature. In the future, rapid diagnostic tests for infectious diseases, like flu, Dengue or Zika, and urinalysis will become common.

"There is virtually no limit to the kinds of testing that can be done using a smartphone," says Dr. John Halamka, Executive Director of the Health Technology Exploration Center at Beth Israel Lahey Health. "No one wants to drive to a clinician's office or lab if that same quality testing can be achieved at a lower cost without leaving home."

SkinVision's skin cancer screening tool, for instance, can tell if a suspicious mole is cancerous. Users take three photos, which are then run through the app's algorithm that compares their lesions with more than three million pictures, evaluating such elements as asymmetry, color, and shape, and spits out an assessment within thirty seconds. A team of in-house experts provide a review regardless of whether the mole is high or low risk, and the app encourages users to see their doctors. The Dutch-based company's app has been used by more than a million people globally in the EU, and in New Zealand and Australia, where skin cancer is rampant and early detection can save lives. The company has plans to enter the U.S. market, according to a spokesperson.

Apps like Instant Heart Rate analyze blood flow, which can indicate whether your heart is functioning normally, while uChek examines urine samples for up to 10 markers for conditions like diabetes and urinary tract infections. Some behavioral apps even have sensors that can spot suicide risks if users are less active, indicating they may be suffering from a bout of the blues.

Even more complex tests are in the research pipeline. Apps like ResAppDX could eventually replace x-rays, CT scans, and blood tests in diagnosing severe respiratory infections in kids, while an EU-funded project called i-Prognosis can track a variety of clues — voice changes, facial expressions, hand steadiness — that indicate the onset of Parkinson's disease.

These hand-held testing devices can be especially helpful in developing countries, and there are pilot programs to use smartphone technology to diagnose malaria and HIV infections in remote outposts in Africa.

"In a lot of these places, there's no infrastructure but everyone has a smartphone," says Scanwell's Koh. "We need to leverage the smartphone in a clinically relevant way."

However, patient privacy is an ongoing concern. A 2019 review in the Journal of the American Medical Association conducted by Australian and American researchers looked at three dozen behavioral health apps, mainly for depression and smoking cessation. They found that about 70 percent shared data with third parties, like Facebook and Google, but only one third of them disclosed this in a privacy policy.

"Patients just blindly accept the end user agreements without understanding the implications."

Users need to be vigilant, too. "Patients just blindly accept the end user agreements without understanding the implications," says Hamalka, who is also the Chief Information Officer and Dean for Technology at Harvard Medical School.

And quality control is an issue. Right now, the diagnostic tools currently available have been vetted by the FDA, and overseas companies like Skin Vision have been scrutinized by the U.K.'s National Health Service and the EU. But the danger is that a lot of apps are going to be popping up soon that haven't been properly tested, due to loopholes in the regulations.

"All we want," says Topol, "are rigorous studies to make sure what consumers are using is validated."

[Correction, August 19th, 2019: An earlier version of this story misstated the specifics of SkinVision's service. A team of in-house experts reviews users' submissions, not in-house dermatologists, and the service is not free.]

Linda Marsa
Linda Marsa is a contributing editor at Discover, a former Los Angeles Times reporter and author of Fevered: Why a Hotter Planet Will Harm Our Health and How We Can Save Ourselves (Rodale, 2013), which the New York Times called “gripping to read.” Her work has been anthologized in The Best American Science Writing, and she has written for numerous publications, including Newsweek, U.S. News & World Report, Nautilus, Men’s Journal, Playboy, Pacific Standard and Aeon.
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