Author summary Healthcare infrastructure implementation could benefit tremendously from national scale screening with passive monitors. Large scale population data could delineate health risks without intruding into daily living. Digital health offers potential solutions if sensor devices of adequate accuracy for predictive models could be widely deployed. The only such current devices are cheap phones, smartphone devices with embedded accelerometers. This limits measures to motion sensor data collected when the phones are carried during normal activities. So measuring walking intensity is possible, but the total activity measure that is possible with 24-hour wearable devices is not. Our study simulates the use of smartphone sensors to predict mortality risk in the largest national cohort with sensor records, the demographically representative UK Biobank. Mortality is the most definitive outcome, with accurate death records for five years available for the 100,000 participants who wore sensor devices. We analyzed…
