Palo Alto, California / May 12, 2020 - Based on 55,000 high-quality datasets contributed by FeverIQ users, we were able to investigate the predictive power of the current COVID differential diagnostic criteria. We tested whether the diagnostic criteria for COVID, the Flu, COVID-neuro, or the common cold were strongly associated with a positive COVID-test. There were about 3,000 users who had been tested (5.5%), and of those, 453 (1%) were COVID-positive. Unfortunately, 21% of the users with a positive COVID test had zero "traditional" COVID symptoms, but instead perfectly fit the diagnostic criteria for the Flu. Similarly, 15% of the COVID-positive users only had symptoms of the common cold but did not have any symptoms of either COVID or the Flu.
What this suggests is that the use of symptoms (e.g. fever or dry cough) to discriminate among COVID, the common cold, and the Flu, results in many mistakes. The plot shows how COVID-positive users scored in four categories, e.g. Flu or COVID. The "Flu" distribution shows that most people with COVID were thought to have a Flu based on their medical symptoms - but in reality, they had COVID.
As more and more users help, we will be able to improve the statistical robustness of these early trends, and we can even think about publishing a scientific paper based on data from our users. This is one of the first examples of how a distributed community can help medicine, all without endangering the privacy of our users.
Note: The COVID-neuro diagnosis combines novel potential COVID-specific symptoms and/or neurological symptoms, such as blue or blistered toes, loss of sense of small, and hallucinations.