Table 1.
Descriptive statistics of sleep and activity measures derived from accelerometer data
| Measure | Mean | S.D. | Min | Max | N |
|---|---|---|---|---|---|
| L5 timing (hours from previous midnight) | 27.32 | 1.07 | 12.29 | 35.35 | 85,830 |
| M10 timing (hours from previous midnight) | 13.70 | 1.21 | 0.26 | 23.44 | 85,723 |
| Sleep midpoint (hours from previous midnight) | 26.99 | 0.91 | 16.25 | 31.98 | 85,502 |
| Sleep duration mean (hours) | 7.30 | 0.86 | 3.00 | 11.87 | 85,502 |
| Sleep duration (SD; (hours)) | 0.93 | 0.57 | 0.00 | 7.26 | 85,068 |
| Sleep efficiency (%) | 76.18 | 7.18 | 28.74 | 100.00 | 85,502 |
| Number of sleep episodes | 17.25 | 3.59 | 5.14 | 29.86 | 85,502 |
| Diurnal inactivity duration | 0.97 | 0.68 | 0 | 9.21 | 85,502 |
Units for the midpoint of the least-active 5 h (L5), midpoint of most-active 10 h (M10), sleep duration, sleep duration variation (SD), sleep midpoint and diurnal inactivity are in hours. Sleep efficiency is a ratio and number of sleep episodes is a count