Table 4.

Descriptive statistics for subscale and total scores of the SHI

Subscale	# items	Possible range	M	SD	Intercorrelations
					1	2
1. Sleep disturbing B/E	7	0-28	11.45	4.33
2. Irregular sleep-wake schedule	4	0-16	7.70	3.21	.34***
3. Total	11	0-44	19.16	6.58	.85***	.77***

Note: ***p < .001. SHI: Sleep Hygiene Index; B/E: behavior and environment.