We investigated the use of digital devices during traditional clinical assessments and in real-world environments in a group of healthy younger (n = 33, 18–40 years) and older (n = 32, 65–85 years) adults. Gait speed estimated in-lab, with or without digital devices, failed to differentiate between age groups, whereas gait speed derived during at-home monitoring was able to distinguish between age groups. Gait speed estimated in-lab was weakly correlated with both median and 95th percentile at-home gait speed. Furthermore, three days of at-home monitoring was sufficient to reliably estimate gait speed in our population, and still capture age-related group differences. Our results suggest that gait speed derived from activities during daily life using data from wearable devices may have the potential to transform clinical trials by non-invasively and unobtrusively providing a more objective and naturalistic measure of functional ability.
