Table 3.
Average Duration of Sleep during the Five Principal Sleep Periods, According to the Driving Schedule.*
| Driving Schedule | Period of Sleep | Overall Average | ||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | ||
| hours of sleep | ||||||
| Steady day | 5.37 | 5.13 | 5.64 | 5.37 | 5.41 | 5.38 |
| Advancing night | 6.36 | 4.54 | 4.73 | 4.35 | 3.85 | 4.76 |
| Steady night | 3.22 | 3.88 | 4.41 | 4.28 | 3.38 | 3.83 |
| Delaying evening | 6.73 | 4.75 | 4.71 | 5.16 | 4.27 | 5.12 |
| Overall average | 5.42 | 4.57 | 4.87 | 4.79 | 4.23 | 4.78 |
*
There was a significant difference among driving schedules (P<0.001 by analysis of variance). The interaction between driving schedule and period of sleep was also significant (P<0.001).