RT-LAMP test samples showing positive (yellow) and negative (pink) results. (Credit: Soo Khim Chan)

Wearable devices can identify COVID-19 cases earlier than traditional diagnostic methods and can help track and improve management of the disease, researchers report in one of the first studies on the topic.

The Warrior Watch Study found that subtle changes in a participant’s heart rate variability (HRV) measured by an Apple Watch were able to signal the onset of COVID-19 up to seven days before the individual was diagnosed with the infection via nasal swab, and also to identify those who have symptoms.

The researchers found that 7–14 days after diagnosis with COVID-19, the HRV pattern began to normalize and was no longer statistically different from the patterns of those who were not infected. The study’s authors say the technology not only allows tracking and predicting health outcomes, but also intervention in a timely and remote manner, which is essential during a pandemic that requires people to stay apart.