Table 2.
Mean (SD) of sleep-wake variables and self-soothing percent from 1 to 12 months
| 1 month | 3 months | 6 months | 9 months | 12 months | |
|---|---|---|---|---|---|
| Total sleep time (min) | 341.38 (112.86) | 445.46 (116.92) | 477.88 (130.39) | 469.14 (138.84) | 480.49 (134.31)* |
| Longest sleep period (min) | 181.01 (58.18) | 281.38 (106.63) | 285.68 (131.88) | 284.34 (123.90) | 283.17 (120.50)* |
| # Night awakenings | 4.12 (2.57) | 2.78 (1.75) | 3.02 (2.09) | 2.81 (2.52) | 2.62 (2.03)* |
| Quiet sleep (%)a | 24.92 (8.98) | 38.46 (6.85) | 45.00 (8.45) | 49.96 (8.06) | 51.73 (6.82)* |
| Active sleep (%) | 66.01 (9.52) | 55.83 (6.12) | 48.25 (7.29) | 43.71 (7.15) | 40.88 (8.71)* |
| Out of crib (%) | 21.99 (16.12) | 8.18 (9.31) | 7.36 (11.22) | 6.36 (9.60) | 6.59 (10.00)* |
| Awake (%) | 5.49 (3.46) | 4.67 (3.29) | 5.70 (3.76) | 4.80 (4.60) | 5.19 (4.51) |
| Self-soothing (%) | 27.55 (26.18) | 33.25 (30.02) | 43.25 (38.02) | 47.55 (37.67) | 46.39 (36.31)* |
a
Percentages of QS, AS, OOC, and AW do not add up to 100% because the denominator for QS% is total recording period and the denominator for AS% is total sleep time.
*
p < .01.