Table 4.

Mean differences in the 10-word recall test score (95% confidence interval) by frequency of morning tiredness

	Frequency of morning tiredness				P for trend
	Never to < 1–2days/month	1–2 days/week	3–4 days/week	Almost daily
No. of subjects	25,411	1,644	615	1,000	–
Crude model	Ref.	−0.05 (−0.14 to 0.04)	−0.13 (−0.27 to 0.02)	−0.36 (−0.47 to −0.24)***	< 0.001
Model 1	Ref.	−0.07 (−0.16 to 0.02)	−0.15 (−0.29 to −0.005)*	−0.25 (−0.36 to −0.13)***	< 0.001
Model 2	Ref.	−0.07 (−0.16 to 0.02)	−0.12 (−0.26 to 0.02)	−0.23 (−0.34 to −0.12)***	< 0.001

Model 1: adjusting for age and sex, employment, occupation, education, smoking, drinking, physical activity, tea consumption and self-rated health

Model 2: adjusting for age, sex, employment, occupation, education, smoking, drinking, physical activity, tea consumption, self-rated health, waist circumference, HDL- and LDL-cholesterol, fasting plasma glucose, systolic blood pressure, sleeping duration, napping and insomnia.

^*P < 0.05,

^***P < 0.001.