Physical Activity Self-Report
There are four instruments that collect physical activity data by self reports.
The ACT24 is a web-based data collection instrument that allows participants to self-report their activity in the past 24 hours. Participants were asked to place activities on a 24-hour timeline consisting of 5-minute intervals, to provide complete coverage of the day's activities (midnight to midnight). Participants completed the ACT24 six times during the study with two months between administrations. At each assigned interval, the study center contacted participants and asked them to complete the ACT24 within 24 hours. Participants received email and telephone reminders from the study center to complete the ACT24. If the participant did not complete the ACT24 in the specified timeframe, it was reassigned three to five days after the missed completion date. An ACT24 administration was reassigned up to two times within the month before it was considered incomplete. In summary: each participant was allowed three attempts, assigned on different days, to complete the assigned ACT24 task for each interval. A few participants provided more than one complete ACT24 within a specified timeframe.
ACT24 data are provided in multiple files and formats:
- 5-minute epoch files (contain multiple activities occurring within a 5 minute block and related MET information)
- First complete ACT24 within scheduled timeframe (act24_5min.sas7bdat)
- Additional complete ACT24s within scheduled timeframe (act24_5min_secondary_complete.sas7bdat)
- Incomplete ACT24s (act24_5min_not_complete.sas7bdat)
- Per Activity files (contain additional detailed information about each activity)
- First complete ACT24 within scheduled timeframe (act24_activity.sas7bdat)
- Additional complete ACT24s within scheduled timeframe (act24_activity_secondary_complete.sas7bdat)
- Incomplete ACT24s (act24_activity_not_complete.sas7bdat)
- Respondent files (contain information about participant interface with web-based system)
All free-text responses provided by participants have been removed from these data files. Activities with free-text responses were reviewed and placed into the existing activity classification. The activity classification was also expanded to include additional activities that did not neatly fall within the existing classification.
The ACT24 web tool provides the Metabolic Equivalent of Task (MET) levels according to the 2000 Compendium of Physical Activities. An up-converted set of MET levels using the 2011 Compendium of Physical Activities (detailed at bottom of page) is also provided in these datasets.
You may view data dictionaries and formats for the ACT24 files. Datasets can be obtained by submitting a request.