Table 2.

Means, standard deviations, and correlations.

Variable	M	SD	1	2	3	4	5	6	7	8	9
1. Subjective sleep quality	1.27	0.69	–
2. Sleep latency	1.39	0.99	0.47***	–
3. Sleep duration	0.97	0.74	0.48***	0.23***	–
4. Habitual sleep efficiency	0.31	0.66	0.36***	0.29***	0.48***	–
5. Sleep disturbances	1.26	0.50	0.38***	0.35***	0.18***	0.27***	–
6. Use of sleeping medication	0.46	0.89	0.27***	0.30***	0.17***	0.21***	0.25***	–
7. Daytime dysfunction	1.55	0.84	0.44***	0.27***	0.34***	0.21***	0.35***	0.20***	–
8. Global sleep quality	7.22	3.40	0.75***	0.69***	0.64***	0.60***	0.57***	0.57***	0.63***	–
9. Sleepiness	9.41	4.56	0.33***	0.18***	0.33***	0.20***	0.25***	0.16***	0.49***	0.44***	–

Means and standard deviations presented are from all observations across time points.

^***p < 0.001.