Table 1.
Accelerometer physical activity/inactivity indicator variables
| Accelerometer variable | Defined |
|---|---|
| Volume indicators* | |
| Activity counts/day | Total activity counts accumulated over 1,440 minutes |
| Uncensored steps/day | Total raw steps accumulated over 1,440 minutes |
| Censored steps/day | Total steps accumulated over 1,440 minutes after censoring out those steps taken at an intensity < 500 activity counts/minute |
| Rate indicators* | |
| Activity counts/minute | Total activity counts accumulated over 1,440 minutes, divided by time worn |
| Uncensored steps/minute | Total raw steps accumulated over 1,440 minutes (24 hours or one day), divided by time worn |
| Censored steps/minute | Total steps accumulated over 1,440 minutes after censoring out those steps taken at an intensity < 500 activity counts/minute, divided by time worn |
| Time indicators (minutes)* | |
| Non-wear time | 1,440 minutes minus wear time |
| Time in sedentary intensity | Total time < 100 activity counts/minute |
| Time in low intensity | Total time 100-499 activity counts/minute |
| Time in light intensity | Total time 500-2,019 activity counts/minute |
| Time in moderate intensity | Total time 2,020-5,999 activity counts/minute |
| Time in vigorous intensity | Total time > 5,999 activity counts/minute |
| Achievement of public health guideline indicator | |
| Y/N achievement of public health guidelines | Percent achieving ≥ 30 minutes of at least moderate intensity in modified 10-minute bouts** on at least 5 of 7 days |
| Break in sedentary time indicator* | |
| Transitions/day | Total occurrences of when activity counts rose from < 100 activity/counts in one minute to ≥ 100 activity counts in the subsequent minute |
| Step-defined activity levels (%) | |
| Basal activity | < 2,500 censored steps/day |
| Limited activity | 2,500 to 4,999 steps/day |
| Low active | 5,000-7,499 steps/day |
| Somewhat active | 7,500-9,999 steps/day |
| Active | 10,000-12,499 steps/day |
| Highly active | ≥ 12,500 steps/day |
*averaged over number of days worn
**10 or more consecutive minutes above the moderate intensity activity count threshold, with allowance for interruptions of 1 or 2 minutes below threshold. A bout was terminated by 3 minutes below threshold.