Table 4.

Association between sleep behaviours and suicidal ideation according to multiple logistic regression analysis.

	Model 1	Model 2	Model 3
	OR 95% CI	OR 95% CI	OR 95% CI
Bedtime
23:30 or earlier (ref)	1	1	1
23:30–00:30	1.02 (0.54–1.95)	1.01 (0.53–1.93)	1.03 (0.53–2.02)
00:30–01:30	1.64 (0.87–3.10)	1.66 (0.87–3.14)	1.56 (0.80–3.04)
Later than 01:30	2.04 (0.95–4.37)	1.88 (0.86–4.09)	1.53 (0.68–3.46)
Wake time
06:00 or earlier (ref)	1	1	1
06:00–07:00	0.66 (0.42–1.02)	0.71 (0.44–1.13)	0.68 (0.42–1.12)
07:00–08:00	0.70 (0.40–1.22)	0.74 (0.40–1.34)	0.66 (0.35–1.25)
Later than 08:00	0.88 (0.36–2.16)	0.86 (0.34–2.17)	0.86 (0.33–2.26)
Sleep-onset latency
<30 min (ref)	1	1	1
≥30 min	1.34 (0.88–2.04)	1.28 (0.84–1.96)	1.03 (0.66–1.61)
Sleep duration
6 h or less (ref)	1.73 (0.99–3.03)	1.68 (0.94–2.99)	1.52 (0.83–2.79)
6-7 h	1.31 (0.75–2.29)	1.31 (0.74–2.31)	1.38 (0.77–2.50)
7-8 h	1	1	1
>8 h	0.62 (0.25–2.26)	0.74 (0.24–2.25)	0.61 (0.20–1.92)
Sleep quality
Good sleep (ref)	1	1	1
Poor sleep	2.65 (1.81–3.89)	2.44 (1.65–3.59)	1.71 (1.13–2.57)

OR: odds ratio; CI: confidence interval.

Model 1: adjusted for age, gender.

Model 2: adjusted for age, gender, weight category, exercise habits, exercise duration, breakfast habits, smoking habits, drinking habits, financial difficulty, living condition, commute time, and part-time job.

Model 3: adjusted for all variables in model 2 and depressive symptoms.