Table 4.

Comparing duration of uninterrupted sleep before first awakening to void, time in bed and NPi with sleep restlessness as scored in CES-D questionnaire

Sleep restlessness score	Duration of uninterrupted sleep (minutes)		Time in bed (minutes)		NPi
	Mean (SD)	Difference (p-value)	Mean (SD)	Difference (p-value)	Mean (SD)	Difference (p-value)
0 (reference)	293 (106)	-----	460 (64)	-----	29.16 (9.33)	-----
1-- some of the time (2–3 days)	297 (73)	6 (.79)	506 (70)	51 (.01)	35.94 (9.39)	5.57 (.07)
2--occasionally (3–4 days)	230 (79)	−64 (<.01)	509 (92)	48 (.02)	40.2 (11.28)	8.28 (<.01)
3--all of the time (5–7 days)	173 (61)	−127 (<.01)	508 (79)	39 (.06)	42.1 (12.26)	10.26 (<.01)