Table 3.

Multivariable linear regression predicting associations between psychological risk factors measured at entry to university and insomnia symptoms measured at completion of first year^a

Sleep Condition Indicator	Cohort 1 (2018–2019)					Cohort 2 (2019–2020)
	ΔR2	β	s.e. β	Standardised β	P-value	ΔR2	β	s.e. β	Standardised β	P-value
Control variables	0.04					0.05
Constant		23.27	2.31		<0.001		23.83	3.01		<0.001
Female		1.70	0.41	0.10*	<0.001		2.07	0.57	0.12*	<0.001
Lifetime sleep disorderb		7.32	1.08	0.17*	<0.001		7.94	1.40	0.19*	<0.001
Adjusted model	0.10					0.14
Constant		28.34	2.52		<0.001		25.01	3.57		<0.001
Female		0.73	0.39	0.05	0.06		0.25	0.55	0.01	0.64
Lifetime sleep disorderb		5.42	1.03	0.13*	<0.001		5.99	1.30	0.14*	<0.001
Locus of control
Internalc,d		−0.09	0.08	−0.03	0.26		–	–	–	–
Externalc,d		0.10	0.04	0.07*	0.02		–	–	–	–
Perfectionism
Personal standardse,f		–	–	–	–		0.05	0.08	0.02	0.55
Evaluative concernse,f		–	–	–	–		0.40	0.13	0.13*	< 0.01
Self-esteemg		−0.39	0.04	−0.29*	<0.001		−0.38	0.05	−0.30*	<0.001
Adjusted R2 for final model	0.14					0.20

^a.Continuous value measured by the Sleep Condition Indicator, with high scores representing worse insomnia symptoms.

^b.Student-reported at entry to university.

^c.No locus of control measures available for cohort 2.

^d.Subscale of German Socio-Economic Panel locus of control scale.

^e.No perfectionism measures available for cohort 1.

^f.Subscale of Clinical Perfectionism Questionnaire.

^g.Rosenberg Self-Esteem Scale.

^*P < 0.05.