Table 2.

The task completion rate during think-aloud walkthroughs in phase 2, where the usability of Motus was evaluated in free-living settings. Having received a package, including a sensor, patch, and information letter, participants opened the package and followed instructions without prompting. After app login, researchers prompted the performance of further tasks (below).

Task		Completed task (%)	Participant suggestions for improvement
Websitea			There should be an indication when registration is completed
	Find registration link	100
	Read information and provided consent	100
Packageb			Clarify how often the app should be used each day
	Read information letter	100
	Proceed to download the app	36
App login			None
	Type the correct telephone number	100
	Receive and use a single-use login code	100
	Accept terms of use	100
Sensor attachment			There should be numbers on the patch indicating the sequence that adhesive covers should be removed
	Read the instructions	100
	Attach sensor correctly	100
	Execute correct calibration	100
App home screen			None
	Locate diary entries	100
	Locate instructions in the drop-down menu	83
	Locate sensor status	92
	Locate contact information	92
Diary			Provide clearer instruction on how to register work periods that cross midnight
	Select the correct day	100
	Fill out work hours correctlyc	100
	Fill out sleep hours correctly	100
Check sensor status			Provide a video instruction
	Find the sensor status	42
	Use the “search for sensor” function	50
	Find contact information	92

^aSeven out of 12 completed registration before the web-based meeting.

^bOne participant opened the package before the web-based meeting.

^cTwo participants held the web-based meeting on a day off, so they did not register work hours on day 1.