Table 5.

Estimates of fixed effects of generalized multilevel model for night-to-night instability (square successive differences, SSDs) of sleep diary and pre-sleep arousal measures

Dependent variable	Fixed effects	Coefficient	SE	t	P
Sleep diary measures		γ
Sleep onset latency – SSDs	Intercept	6.90	0.23	30.42	< 0.001
	Gender	-2.30	3.47	-0.66	0.509
	Group	0.09	0.07	1.21	0.226
Wake after sleep onset – SSDs	Intercept	8.01	0.14	57.33	< 0.001
	Gender	-2.95	2.15	-1.37	0.171
	Group	0.02	0.04	0.48	0.632
Total sleep time - SSDs	Intercept	9.19	0.09	95.04	< 0.001
	Gender	-1.28	1.46	-0.88	0.381
	Group	0.14	0.03	4.53	0.000
Sleep efficiency – SSDs	Intercept	5.29	0.12	42.01	< 0.001
	Gender	-1.64	1.95	-0.84	0.400
	Group	0.07	0.04	1.81	0.072
Pre-sleep arousal ratings (VAS)
Active mind – SSDs	Intercept	6.28	0.16	38.07	< 0.001
	Gender	-0.96	2.48	-0.39	0.697
	Group	0.09	0.05	1.69	0.093
Anxious – SSDs	Intercept	5.77	0.22	26.66	< 0.001
	Gender	-1.83	3.20	-0.57	0.567
	Group	0.16	0.07	2.35	0.019

Gender variable was coded as 0: Male and 1: Female. Group variable was coded as 0: Primary insomnia and 1: Insomnia related to a mental disorder.

VAS, visual analogue scale.