Table 2.
Association between baseline BMIz and insomnia severity, stratified by age.
| Children (Ages 2–10.9 years) | Adolescents (Ages 11–18 years) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Step | Predictor | R2 | β (SE) | T | Step | Predictor | R2 | β | T |
| PISI Total Score | |||||||||
| 1 | Income | .040*** | −0.20 (0.07) | −5.44*** | 1 | Income | .012* | −0.11 (0.11) | −2.03* |
| 2 | .040*** | 2 | .026** | ||||||
| Income | −0.20 (0.07) | −5.39*** | Income | −0.10 (0.11) | −1.91 | ||||
| BMIz | 0.00 (0.17) | 0.01 | BMIz | 0.12 (0.27) | 2.32* | ||||
| PISI Factor 1 (Difficulty Falling Asleep) | |||||||||
| 1 | Income | .054*** | −0.23 (0.05) | −6.35*** | 1 | Income | .017* | −0.13 (0.07) | −2.47* |
| 2 | .054*** | 2 | .028** | ||||||
| Income | −0.23 (0.05) | −6.32*** | Income | −0.12 (0.07) | −2.36* | ||||
| BMIz | −0.01 (0.11) | −0.13 | BMIz | 0.10 (0.17) | 1.98* | ||||
| PISI Factor 2 (Difficulty Staying Asleep) | |||||||||
| 1 | Income | .028*** | −0.17 (0.04) | −4.51*** | 1 | Income | .016* | −0.13 (0.06) | −2.40* |
| 2 | 2 | .021* | |||||||
| Income | .028*** | −0.17 (0.04) | −4.50*** | Income | −0.12 (0.06) | −2.31* | |||
| BMIz | −0.01 (0.10) | −0.26 | BMIz | 0.08 (0.16) | 1.41 | ||||
| PISI Daytime Sleepiness | |||||||||
| 1 | Income | .002 | −0.05 (0.02) | −1.28 | 1 | Income | .002 | 0.04 (0.03) | 0.83 |
| 2 | .005 | 2 | .017* | ||||||
| Income | −0.04 (0.02) | −1.10 | Income | 0.05 (0.03) | 0.97 | ||||
| BMIz | 0.05 (0.05) | 1.41 | BMIz | 0.12 (0.07) | 2.31* | ||||
*P < .05; **P < .01; ***P < .001. BMIz = body mass index Z-score, PISI = Pediatric Insomnia Severity Index, SE = standard error.