Smartphone sensor-based tests
Key neurologic functions underlying cognitive information processing speed were assessed by the e-SDMT. It instructed participants to correctly match as many symbols as possible to their paired digits within 90 s, according to a symbol–digit key also displayed on the smartphone screen.The Draw a Shape Test assessed fine finger movements, or dexterity; participants were prompted to draw six pre-written shapes of increasing complexity (two diagonal lines, a square, a circle, a figure-of-8, and a spiral). By comparison, the Pinching Test measured fine pinching or grasping dexterity. Participants were instructed to successfully pinch as many circular tomatoes appearing on the screen as possible within 30 s, with new tomatoes appearing at random locations.Finally, gait and balance were assessed by three active tests: the SBT, 2MWT, and UTT. The SBT required participants to stand as still as possible for 30 s. The 2MWT assessed regular, straight walking for 2 min. The UTT, which measured both dynamic balance and gait, instructed participants to perform five consecutive U-turns that were at least 4 m apart, within a minute. The use of an assistive device and/or orthotic was permitted as needed while performing the 2MWT and UTT.