The Impact of Sleep Timing, Sleep Duration, and Sleep Quality on Depressive Symptoms and Suicidal Ideation amongst Japanese Freshmen: The EQUSITE Study
Table 3
Association between sleep behaviours and depressive symptoms according to multinominal logistic regression analysis.
Model 1
Model 2
Model 3
OR (95% CI)
OR (95% CI)
OR (95% CI)
Bedtime
23:30 or earlier
1
1
1
23:30–00:30
1.06 (0.77–1.46)
1.07 (0.78–1.49)
1.11 (0.79–1.55)
00:30–01:30
1.30 (0.94–1.81)
1.32 (0.95–1.84)
1.32 (0.92–1.89)
Later than 01:30
1.75 (1.15–2.65)
1.60 (1.05–2.44)
1.57 (0.99–2.47)
Wake time
06:00 or earlier (ref)
1
1
1
06:00–07:00
1.07 (0.83–1.38)
1.04 (0.80–1.35)
1.13 (0.86–1.47)
07:00–08:00
1.28 (0.95–1.72)
1.17 (0.85–1.63)
1.33 (0.95–1.85)
Later than 08:00
1.20 (0.72–1.98)
1.07 (0.63–1.76)
1.18 (0.68–2.05)
Sleep-onset latency
<30 minutes (ref)
1
1
1
30 minutes
1.57 (1.25–1.98)
1.53 (1.22–1.93)
1.52 (1.21–1.92)
Sleep duration
6 h or less (ref)
1.21 (0.91–1.61)
1.31 (0.97–1.76)
6-7 h
0.97 (0.74–1.28)
1.04 (0.78–1.37)
7-8 h
1
1
>8 h
1.36 (0.87–2.13)
1.36 (0.87–2.14)
Sleep quality
Good sleep (ref)
1
1
1
Poor sleep
2.49 (2.02–3.06)
2.45 (1.98–3.04)
2.71 (2.14–3.45)
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 sleep duration.
