Table 4.
The relationship between sleep time and mental health in participants aged 4–6 years.
| Sleep Time (h/day) | p for Trend a | ||||
|---|---|---|---|---|---|
| <9 | 9 | 10 | ≥11 | ||
| Participants (n) | 191 | 1368 | 1530 | 294 | |
| SDQ ≥16 (n) | 59 | 328 | 368 | 72 | |
| Crude RR | 1.29 (1.02−1.63) | 1.00 (reference) | 1.00 (0.88−1.14) | 1.02 (0.82−1.28) | 0.156 |
| Age-sex-adjusted RR b | 1.30 (1.04−1.64) | 1.00 (reference) | 0.98 (0.86−1.12) | 0.97 (0.78−1.21) | 0.053 |
| Multivariate RR c | 1.22 (0.98−1.53) | 1.00 (reference) | 1.01 (0.89−1.15) | 0.96 (0.77−1.21) | 0.131 |
RR, risk ratio; a p for trend values were calculated with sleep time as a continuous variable; b Adjusted for sex (male or female) and age (4 years old, 5 years old, or 6 years old); c Adjusted for age and sex plus current state of health (very good or good, normal, or poor or very poor), napping time (none, <1 h/day, 1−2 h/day, or ≥2 h/day), evacuation (inside Fukushima or to other prefectures), tsunami experience (yes or no), nuclear reactor accident experience (yes or no), and respondent (mother, father, or other).