Table 2.
Mean differences in the 10-word recall test score (95% confidence interval) by groups of sleep duration
| Sleep duration, hours per day |
P for linear trend (3 to 7 h) | P for linear trend (7 to ≥ 10 h) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| 3–4 | 5 | 6 | 7 | 8 | 9 | ≥ 10 | |||
| No. of subjects | 1,074 | 2,768 | 7,016 | 8,598 | 6,734 | 1,546 | 934 | – | – |
| Crude model | −0.51 (−0.62 to −0.39)*** | −0.32 (−0.40 to −0.25)*** | −0.17 (−0.23 to −0.11)*** | Ref. | 0.02 (−0.04 to 0.08) | −0.15 (−0.25 to −0.05)** | −0.45 (−0.57 to −0.32)*** | < 0.001 | < 0.001 |
| Model 1 | −0.22 (−0.34 to −0.11)*** | −0.09 (−0.17 to −0.01)* | −0.03 (−0.09 to −0.02) | Ref. | 0.03 (−0.03 to 0.08) | −0.12 (−0.22 to −0.02)* | −0.34 (−0.46 to −0.22)*** | < 0.001 | < 0.001 |
| Model 2 | −0.17 (−0.30 to −0.06)** | −0.07 (−0.15 to −0.005) | −0.03 (−0.09 to 0.03) | Ref. | 0.03 (−0.03 to 0.09) | −0.11(−0.20 to −0.008)* | −0.32 (−0.44 to −0.20)*** | 0.001 | < 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, daytime napping, feeling tired in the morning and insomnia.
*
P < 0.05,
**
P < 0.01,
***
P < 0.001.