Table 1.
Descriptive analysis on socio-demographic characteristics, sleep and circadian activity rhythm in infants.
| Mean or N | SD or % | |
|---|---|---|
| Socio-demographic characteristics | ||
| Age (months) | 12.1 | 0.24 |
| Male | 25 | 48.1 |
| Paternal educational level | ||
| High school and below | 5 | 9.6 |
| College | 40 | 76.9 |
| Postgraduate | 7 | 13.5 |
| Maternal educational level | ||
| High school and below | 6 | 11.5 |
| College | 36 | 69.2 |
| Postgraduate | 10 | 19.2 |
| Maternal mood state at 12-montha | 27.74 | 29.79 |
| Current breastfed | 12 | 23.1 |
| Bedroom sharing | 49 | 94.2 |
| Sleep-related parameters | ||
| Total sleep time (min)b | 665.66 | 47.68 |
| Daytime sleep time (min) | 119.59 | 42.28 |
| Characteristics of nighttime sleep | ||
| Nighttime sleep time (min) | 546.06 | 44.13 |
| Sleep onset latency (min) | 10.79 | 11.44 |
| Wake after sleep onset (min) | 18.68 | 12.42 |
| Nighttime sleep efficiency (%) | 92.59 | 3.71 |
| Circadian-related parameters | ||
| Inter-daily stability | 0.58 | 0.10 |
| Intra-daily variability | 0.87 | 0.14 |
| Lowest 5 h activity | 6245.61 | 3466.37 |
| Lowest 5 h activity onset time | 1.97 | 2.05 |
| Most 10 h activity | 211557.69 | 52861.05 |
| Most 10 h activity onset time | 9.76 | 1.51 |
| Relative amplitude | 0.94 | 0.03 |
aMaternal mood state was measured by the Total Mood Disturbance score from the Profile of Mood State.
bTotal sleep time was calculated as the sum of daytime and nighttime sleep time.