Alliance for Pandemic Preparedness

August 14, 2020

App-Based Tracking of Self-Reported COVID-19 Symptoms



  • Zens et al. report findings from the COVID-19 Symptom Tracker study, an app-based daily self-reporting study. Between April 8 and May 15, 22,327 individuals living in Germany installed the app, of which 11,829 (59%) completed the symptom questionnaire at least once. Of the 291 participants who received a SARS-CoV-2 PCR test, 22% were positive. Untested participants reported a mean of 0.8 symptoms compared to 5.6 symptoms among tested participantsChills, fever, loss of smell, nausea, vomiting, and shortness of breath were the strongest predictors of SARS-CoV-2 infection. Diabetes and chronic heart disease were significant risk factors for positivity. 

Zens et al. (July 2020). App-Based Tracking of Self-Reported COVID-19 Symptoms. Journal of Medical Internet Research.