Table 3.
Results from the binary logistic regression analyses: an approximation of the insomnia disorder (DSM-5) and academic performance/failure.
| Failed study examinations (reference category: no failed examinations, OR = 1) |
Delayed study progression (reference category: no delay, OR = 1) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Model 1 (crude) |
Model 2 (adjusted for backgrounda) |
Model 3 (adjusted for backgrounda + DSPD) |
Model 4 (adjusted for backgrounda + DSPD + psychological distressb) |
Model 1 (crude) |
Model 2 (adjusted for backgrounda) |
Model 3 (adjusted for backgrounda + DSPD) |
Model 4 (adjusted for backgrounda + DSPD + psychological distressb) |
|
| OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
| Insomnia (reference category: no insomnia) | 1.42 (1.36–1.48)*** | 1.31 (1.25–1.37)*** | 1.30 (1.25–1.36)*** | 1.15 (1.10–1.20)*** | 1.44 (1.34–1.55)*** | 1.32 (1.22–1.42)*** | 1.31 (1.22–1.42)*** | 1.09 (1.01–1.18)* |
| Insomnia and sleep duration (reference category: no insomnia and normal sleep duration) | ||||||||
| No insomnia and short sleep | 1.56 (1.43–1.71)*** | 1.41 (1.29–1.54)*** | 1.41 (1.29–1.54)*** | 1.34 (1.23–1.47)*** | 1.38 (1.18–1.62)*** | 1.24 (1.06–1.46)** | 1.24 (1.06–1.46)** | 1.15 (0.98–1.35) |
| No insomnia and long sleep | 0.96 (0.92–1.01) | 1.02 (0.97–1.08) | 1.02 (0.97–1.08) | 1.04 (0.98–1.09) | 1.01 (0.92–1.11) | 1.11 (1.01–1.22)* | 1.11 (1.01–1.22)* | 1.13 (1.03–1.24)* |
| Insomnia and normal sleep | 1.36 (1.29–1.44)*** | 1.30 (1.22–1.37)*** | 1.29 (1.22–1.36)*** | 1.15 (1.09–1.23)*** | 1.40 (1.27–1.55)*** | 1.32 (1.20–1.46)*** | 1.32 (1.19–1.46)*** | 1.11 (1.00–1.23) |
| Insomnia and short sleep | 1.64 (1.52–1.78)*** | 1.45 (1.34–1.57)*** | 1.44 (1.33–1.56)*** | 1.23 (1.13–1.34)*** | 1.45 (1.27–1.67)*** | 1.26 (1.10–1.45)** | 1.26 (1.09–1.45)** | 0.98 (0.85–1.13) |
| Insomnia and long sleep | 1.49 (1.38–1.62)*** | 1.47 (1.35–1.60)*** | 1.46 (1.34–1.59)*** | 1.31 (1.20–1.43)*** | 1.72 (1.51–1.97)*** | 1.73 (1.51–1.98)*** | 1.72 (1.50–1.98)*** | 1.45 (1.26–1.67)*** |
∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.
CI, confidence interval; DSPD, an approximation of the delayed sleep phase disorder; OR, odds ratio.
a
Background variables include age, sex, relationship status, care for children, immigrant status, income, financial difficulties, study length and programme, physical exercise, smoking, AUDIT classification, and BMI classification.
b
Psychological distress refers to the score on HSCL-25, where the sleep item on the depression subscale had been taken out.