Table 4. OR (95% CI) values for EDS by sex, school grade, frequency of self-perceived snoring/apnea, BMI, sleep duration during a school day, and subjective perception of sleep duration.

	Model 1	Model 2
Sex
Male	0.72 (0.65–0.79)	0.74 (0.67–0.81)
School grade
First	1 (reference)	1 (reference)
Second	0.90 (0.81–1.01)	0.91 (0.81–1.01)
Third	0.84 (0.74–0.94)	0.84 (0.75–0.94)
Frequency of self-perceived snoring
Never	1 (reference)
Occasionally	1.62 (1.44–1.82)
Often	2.07 (1.70–2.55)
Habitually	3.18 (2.43–4.18)
Frequency of self-perceived apnea
Never		1 (reference)
Occasionally		2.21 (1.90–2.58)
Often		2.41 (1.75–3.33)
Habitually		6.01 (3.64–9.92)
BMI
Underweight	0.90 (0.73–1.09)	0.87 (0.72–1.07)
Normal	1 (reference)	1 (reference)
Overweight	0.81 (0.60–1.10)	0.86 (0.63–1.16)
Obese	0.85 (0.73–1.00)	0.92 (0.79–1.08)
Sleep duration during a school day, hours
<5	1.56 (1.34–1.80)	1.56 (1.34–1.80)
≥5 and <6	1 (reference)	1 (reference)
≥6 and <7	1.05 (0.93–1.18)	1.05 (0.94–1.19)
≥7	0.93 (0.82–1.06)	0.93 (0.82–1.06)
Subjective perception of sleep duration
Adequate	1 (reference)	1 (reference)
Considerable	1.39 (1.07–1.80)	1.36 (1.05–1.77)
Insufficient	2.56 (2.25–2.91)	2.58 (2.26–2.93)

Model 1: adjusted frequency of self-perceived snoring, Model 2: adjusted frequency of self-perceived apnea.

BMI: body mass index, CI: confidence interval, EDS: excessive daytime sleepiness, OR: odds ratio.