This variable is only available in MAP.

Average activity per active hour is an index of intensity of daily activity. Objective measures of physical activity are obtained using a portable actigraph: AX3 (2020-present), GENEActiv (2018-2020), Actical (2005-2018). See Actigraphy category description for detailed information on each device. Participants are asked to wear the actigraph 24 hours per day for up to 10 days.

Activity per active hour is calculated by summing activity from all nonzero 15-second epochs and dividing by the number of hours with activity (i.e., the time of all nonzero epochs) during each day.