Symptom-assessment app uses AI to learn about patients

By Rosie Lombardi

Dr Claire NovorolMost patients look up their symptoms online at websites that may not be accurate or reputable, and often come to their medical visits armed with incorrect information. To tackle this, a new app called Ada intelligently checks and tracks symptoms by asking personalized questions, and uses AI to “learn” the user’s medical history over time. Developed by a team of doctors and scientists based in London, Berlin and Munich, the app quickly climbed to no.1 medical app in the App Store in Canada and more than 120 countries since its global launch last fall – more than any other iOS app in 2016.

The company was started up six years ago to develop technology that supports doctors and clinical decision making, says Dr. Claire Novorol (pictured), Ada Health co-founder and chief medical officer.

The Ada app is free to download, and it only requires limited information such as email address and date of birth to sign-up, says Novorol. “Then Ada talks you through the next steps to get to the core of the app, which is a personalized health assessment. It will ask what your symptoms are, then it asks a number of questions to determine the most likely potential cause.”

Novorol emphasizes that Ada is very different from existing online symptom checkers and paper checklists that are often collected from waiting rooms. These systems are typically static: they only allow users to enter a single initial symptom, ask generic questions and have a fixed decision tree, she explains.

“Our system is based on a very sophisticated probabilistic reasoning technology. Based on what the patient enters, Ada computes in real time what the next most useful and most appropriate question to ask will be. It considers the entirety of the medical knowledge in its huge database, which contains about 1500 medical conditions and thousands of symptoms. All of that knowledge is taken into consideration when it calculates what question it should ask next.”

Another issue is that most conditions manifest themselves with several symptoms, she says. “But in traditional symptom-checkers, you can usually only enter one symptom, such as headache. You typically don’t have the option to enter headache and abdominal pain and fever. The system just takes headache and then it has a pre-written pathway of questions. It asks the same questions of everybody who enters headache.”

Instead, Ada works differently to collect more meaningful information. “You can enter as many symptoms as you want, and the system will take them all into account and ask questions that are relevant within that context. It can even deal with multi-morbidity when it appears that symptoms may be caused by a combination of problems. Ada then provides data on the percentage of people with those symptoms who typically have each condition.”

Novorol says Ada is the most accurate symptom-assessment checker available today. “As far as we are aware Ada is significantly more powerful than anything else currently out there.”

The app benefits patients because they can use Ada, with its tried, tested and true database of medical information and probabilistic algorithms, to find out what their symptoms might mean instead of sifting through all the noise and misinformation they get when they Google.

But it can also be used as a powerful tool to save doctors time and effort. “They can just show their doctors their findings so they don’t have to ask all the same questions again, and they can just pick out the most relevant points to discuss in more detail with the patient.”

Many doctors in the U.K. are using Ada as a triage tool. “Instead of seeing every single patient face-to-face, many family doctors now do telephone triage. Typically, the patient calls the receptionist and then the doctor calls the patient back and asks questions to decide whether they need to come in for a face-to-face appointment or not. We now have a number of practices using Ada to collect the patient’s history in advance of the consultation, and to speed up and facilitate that triage function.”

Several Canadian doctors have contacted Ada Health for advice on how to set up this kind of triage process. “Ada is getting a lot of positive reviews from the medical community. A lot of doctors are proactively contacting us to find out how they can use Ada effectively in their practices.”

A powerful selling point for the medical community is that Ada’s medical intelligence will increase dramatically the more it’s used globally – and the app has already been downloaded by hundreds of thousands of people in 155 countries.

“Ada learns continuously as the system is being used, although there’s also a lot of doctor help in that process. The more users we have and the more assessments performed, the more Ada gets smarter and smarter. So increasing our numbers is a big, big goal for us for 2017.”

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