Health trackers worn on the wrist could pick up Covid-19 days before symptoms even appear, research suggests.
In the study, 1,163 people under the age of 51 in Lichtenstein were followed from the start of the pandemic. They were asked to wear the Ava bracelet at night, with the device saving data every 10 seconds. People have to sleep for at least four hours for it to work. All those in the study took regular rapid antibody tests for Covid while those with symptoms also took a PCR swab test. Overall, 1.5 million hours of physiological data were recorded and Covid was confirmed in 127 people, of which 66 had worn their device for at least 29 consecutive days and were included in the analysis.
Overall, the tracker and computer algorithm identified 68% of Covid-19 positive people two days before their symptoms appeared. The team, including from the Cardiovascular Research Institute of Basel, concluded there were limits to the research, including that not all Covid cases were captured.