Table 1.
Descriptive Statistics and Bivariate Correlations
| Variables | Range | Mean (SD) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. Actigraphy sleep duration (hrs) | 2.20–10.05 | 7.46 (0.99) | |||||||||||
| 2. Actigraphy sleep variability | 00–4.99 | 0.96 (0.55) | −.12* | ||||||||||
| 3. PSQI global | 00–16 | 5.15 (2.97) | −.15* | .25*** | |||||||||
| 4. PSQI perceived sleep quality | 00–3 | 0.80 (0.53) | −.05 | .20*** | .83*** | ||||||||
| 5. PSQI sleep efficiency | 00–3 | 0.32 (0.56) | −.17** | .15* | .67*** | .33*** | |||||||
| 6. PSQI daily disturbances | 00–3 | 1.08 (0.61) | −.14* | .20** | .74*** | .43*** | .29*** | ||||||
| 7. CRP | 001–8.45 | 69 (1.27) | −.07 | .12* | .09 | .12* | .03 | .05 | |||||
| 8. BMI (percentile) | 1–99 | 60.82 (29.15) | −.18** | .11 | .05 | .02 | .00 | .11 | .33*** | ||||
| 9. Age (years) | 14.50–18.42 | 16.39 (0.71) | −.13* | .03 | .03 | −.02 | −.08 | .04 | .24*** | −.01 | |||
| 10. Sex (female = 1) | 57% female | .16** | .06 | .10 | .08 | .08 | .09 | .05 | .01 | .05 | |||
| 11. Parent education (1–11) | 1.50–11.00 | 7.19 (1.81) | .01 | .02 | −.04 | −.03 | −.04 | −.04 | −.18** | −.11 | −.13* | −.12* | |
| 12. Stress (0–4) | 0.33–3.56 | 1.94 (0.62) | .03 | .06 | .42*** | .35*** | .12* | .46*** | .06 | .05 | −.04 | .23*** | .05 |
Note.
*
p < .05,
**
p < .01,
***
p < .001.
Gender was coded such that male = 0 and female = 1. Higher PSQI scores indicated poorer sleep. Range, mean, and SD for CRP were based on untransformed CRP values; correlations were based on log-transformed CRP values.