The Impact of Sleep Timing, Sleep Duration, and Sleep Quality on Depressive Symptoms and Suicidal Ideation amongst Japanese Freshmen: The EQUSITE Study
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.
