Diagnostic app can reveal cause of death without a doctor

We have no cause of death for half of the 55 million people who die each year. A simple app could change that and let countries manage health policies better

Life 17 February 2016
wrapped body prepared for cremation
Families need to know why

TINO SORIANO/National Geographic Creative

CAUSE of death? Unknown. That is the case for at least half of the 55 million or so people who die each year. In many parts of the world there are simply too few doctors to make the diagnosis. Deaths are either not registered at all, or the cause is a guess or left blank on the death certificate. “Both of these things are equally useless for public policy,” says Alan Lopez at the University of Melbourne in Australia. Knowing why people die is essential for managing a country’s health system.

To tackle the problem, Lopez and his colleagues have developed an app that can work out cause of death more accurately than a human doctor. This lets anyone with a smartphone or tablet issue a death certificate.

To get an answer, volunteers interview the dead person’s friends and family using a set questionnaire, entering symptoms into the app. This information is uploaded to a computer and assessed by an algorithm, which provides a ranked list of the most probable causes of death.


If an internet connection is available, this happens at once. Otherwise, interview responses are stored by the app until they can be processed. “I just came from Myanmar where every month, rural midwives send pieces of paper on cause of death through the mail,” says Lopez. “Now, the idea is that they’ll send that information through tablets instead.”

“It is better if doctors don’t get involved since their time can be better spent elsewhere“

Lopez and his colleagues began working on the system in 2005, after winning support from the Bill and Melinda Gates Foundation. To build the diagnostic algorithm, they gathered data from six sites in India, Mexico, Tanzania and the Philippines.

First, they visited local hospitals to identify 12,500 “gold standard” cases – patients with verified diagnoses – for 34 causes of death in adults and 21 in children. They used data from those patients to build a questionnaire.

The team also interviewed around 100 families for each known cause of death, which enabled them to generate typical patterns of responses. They used these to check if their system correctly match responses to cause of death. Once the algorithms were working, they tested the app in field trials in China, Papua New Guinea, the Philippines and Bangladesh. They found that the app was more accurate on average than doctors who reviewed the same data.

The final version of the questionnaire takes just 25 minutes to complete. It is also simple enough for a person with minimal training to administer. In fact, Lopez and his colleagues prefer not to involve doctors in interviews, since their time can be better spent elsewhere and they may end the interview early if they feel they know the cause of death, which makes the app less reliable.

The app is set to be rolled out in 20 countries by 2017. Lopez hopes it will change how governments approach health policy by revealing where best to allocate resources. Brazil is also interested despite only its doctors being allowed to make post-mortem diagnoses. If the app is successful that could change. “In certain situations where there is no physician – in Amazon areas, for example – it could be used for capturing cause of death,” says Maria de Fatima Marinho de Souza at Brazil’s Ministry of Health.

This article appeared in print under the headline “App has death covered”

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