Table 3.
Means and Standard Error for Weekday Sleep Patterns by School Start Time and the Presence/Absence of Technology in the Bedroom
|
SCHOOL START
TIME |
Before 8:00 a.m.
(n=106) |
8:00 – 8:30 a.m.
(n=177) |
8:31 – 9:00 a.m.
(n=74) |
After 9:00 a.m.
(n=50) |
|||||||
| Mean | SE | Mean | SE | Mean | SE | Mean | SE | F(1,402) | p | η p 2 | |
|
| |||||||||||
| Bedtime | 21:46 | 0:06 | 21:48 | 0:04 | 21:55 | 0:07 | 22:39 | 0:09 | 9.63 | <.001 | .07 |
| Wake Time | 6:03 | 0:04 | 6:51 | 0:03 | 7:29 | 0:05 | 8:40 | 0:06 | 99.82 | <.001 | .43 |
| Total Sleep Time | 8.16 | 0.11 | 8.57 | 0.08 | 9.01 | 0.13 | 9.32 | 0.16 | 13.27 | <.001 | .09 |
|
| |||||||||||
|
| |||||||||||
|
CAFFEINATED
BEVERAGESa |
None (n=187) |
One per day
(n=123) |
More than one/day
(n=97) |
||||||||
| Mean | SE | Mean | SE | Mean | SE | F(1,404) | p | η p 2 | |||
|
| |||||||||||
| Bedtime | 21:42 | 0:04 | 22:03 | 0:05 | 22:10 | 0:06 | 9.24 | <.001 | .04 | ||
| Wake Time | 07:03 | 0:04 | 07:06 | 0:06 | 07:10 | 0:07 | 0.20 | .82 | .001 | ||
| Total Sleep Time | 8.83 | 1.11 | 8.51 | 1.19 | 8.42 | 1.11 | 6.99 | <.001 | .03 | ||
Note. Bedtimes and wake times reported in military clock time, total sleep time in hours. ηp2 is a measure of effect size (small = .02, medium = .13, large = .26)
a
Post-hoc analyses (controlling for school group) show significantly later bedtimes for both caffeine use groups compared to no caffeine, as well as significantly shorter sleep duration for both caffeine use groups compared to no caffeine