Table 1

Demographic and clinical characteristics of the study population

	Group; mean ± SD^*

Characteristic	PI	Control	Statistic	p value
Sex, male:female	8:12	8:12	χ²₁ = 0.00	> 0.99
Age, yr	42.7 ± 13.4	44.1 ± 10.6	t₃₈ = −0.37	0.72
BMI	24.5 ± 3.8	23.4 ± 3.3	t₃₈ = 0.97	0.34
ISI	12.8 ± 3.1	1.6 ± 1.9	t₃₈ = 13.62	< 0.001
PSQI	10.0 ± 3.5	2.6 ± 1.8	t₃₈ = 8.31	< 0.001
PSQI – SEI, %	72.8 ± 17.0	93.7 ± 7.7	t₃₈ = −5.01	< 0.001
PSQI – SOL, min	30.8 ± 33.5	13.6 ± 8.3	t₃₈ = 2.23	0.037
PSQI – bedtime	22:57 ± 00:35	23:06 ± 00:48	t₃₈ = −0.69	0.49
PSQI – rise time	6:47 ± 01:05	7:00 ± 01:12	t₃₈ = −0.60	0.55
DBAS-16	4.5 ± 1.4	2.0 ± 1.2	t₃₈ = 6.41	< 0.001
GSES	5.5 ± 2.6	1.0 ± 1.2	t₃₈ = 6.88	< 0.001
PSAS – cognitive	19.2 ± 6.8	10.6 ± 2.6	t₃₈ = 5.30	< 0.001
PSAS – somatic	11.5 ± 3.2	9.1 ± 1.3	t₃₈ = 3.04	0.005
ESS	8.0 ± 4.3	5.6 ± 3.3	t₃₈ = 1.97	0.06
SSS	2.2 ± 1.2	1.8 ± 0.9	t₃₈ = 1.20	0.24
MEQ	54.9 ± 12.9	58.6 ± 7.9	t₃₈ = −1.12	0.27
BDI	6.5 ± 3.9	3.1 ± 3.6	t₃₈ = 2.88	0.006
STAI – trait	38.0 ± 8.7	29.3 ± 4.4	t₃₈ = 4.00	< 0.001

BDI = Beck Depression Inventory; BMI = body mass index; DBAS = Dysfunctional Beliefs and Attitudes about Sleep Scale; ESS = Epworth Sleepiness Scale; GSES = Glasgow Sleep Effort Scale; ISI = Insomnia Severity Index; MEQ = Morningness-Eveningness Questionnaire; PI = primary insomnia; PSAS = Pre-Sleep Arousal Scale; PSQI = Pittsburgh Sleep Quality Index; SD = standard deviation; SEI = sleep efficiency; SOL = sleep-onset latency; SSS = Stanford Sleepiness Scale; STAI = State-Trait Anxiety Inventory.
↵* Unless indicated otherwise.