Table 1. Descriptive statistics (Mean ± SD) for circadian and actigraphic sleep measures for napping (n = 15) and non-napping (n = 5) toddlers.
| Napping | Non-Napping | Statistics | |||
|---|---|---|---|---|---|
| (n = 15) | (n = 5) | t | d | p | |
| Circadian Variables | |||||
| Dim Light Melatonin Onset Time | 19:48 ± 0:42 | 19:10 ± 0:33 | 1.81 | 0.93 | 0.044 |
| Bedtime Phase Difference (min) § | 30.4 ± 33.9 | 25.0 ± 41.1 | -0.29 | 0.15 | 0.773 |
| Sleep Onset Phase Difference (min) § | 63.9 ± 32.5 | 42.0 ± 42.0 | -1.22 | 0.63 | 0.240 |
| Midsleep Phase Difference (min) § | 367.0 ± 28.6 | 379.6 ± 25.3 | -0.87 | 0.45 | 0.394 |
| Wake Time Phase Difference (min) § | 670.1 ± 39.9 | 717.1 ± 33.1 | -2.37 | 1.23 | 0.029 |
| Sleep Variables | |||||
| Bedtime | 20:18 ± 0:36 | 19:35 ± 0:30 | 2.42 | 1.24 | 0.014 |
| Sleep Onset Time | 20:51 ± 0:43 | 19:52 ± 0:30 | 2.84 | 1.46 | 0.006 |
| Midsleep Time | 1:54 ± 0:30 | 1:30 ± 0:23 | 1.65 | 0.85 | 0.058 |
| Wake Time § | 6:58 ± 0:30 | 7:07 ± 0:41 | -0.57 | 0.30 | 0.575 |
| Sleep Onset Latency (min) | 33.0 ± 16.6 | 17.1 ± 10.2 | -2.01 | 1.03 | 0.030 |
| Nighttime Time in Bed (min) | 656.9 ± 38.9 | 705.6 ± 51.9 | -2.24 | 1.16 | 0.019 |
| Nighttime Sleep Duration (min) | 606.3 ± 43.9 | 675.0 ± 56.2 | -2.84 | 1.47 | 0.006 |
| 24-h Sleep Duration (min) § | 708.9 ± 40.2 | 675.0 ± 56.2 | 1.48 | 0.76 | 0.156 |
| Days Napping (of 5) | 3.6 ± 1.2 | - | - | - | - |
| Nap Midpoint Time | 14:43 ± 0:46 | - | - | - | - |
| Nap Duration (min) | 102.6 ± 20.1 | - | - | - | - |
Statistics are shown for independent t-tests (napping versus non-napping participants).
§ indicates a two-tailed test.