Table 1.
Model fit statistics predicting changes in resting heart rate.
| Model 1 | Model 2 | Model 3 | Model 4 | Model 5 | |
|---|---|---|---|---|---|
| Fixed effects β (SE) | |||||
| Intercept | 0.18 (0.10) | 5.85 (2.07)** | 0.38 (0.08)*** | 0.64 (0.07)*** | − 1.18 (1.26) |
| Month | − 0.15 (0.02)*** | − 0.14 (0.03)*** | − 0.13 (0.02)*** | − 0.08 (0.02)*** | − 0.08 (0.01)*** |
| Sleep duration (h) | – | − 0.82 (0.30)** | – | – | 0.27 (0.18) |
| Δ Midsleep (h) | – | – | − 2.38 (0.29)*** | – | − 1.25 (0.28)*** |
|
Δ Midsleep Variability (h) |
– | – | – |
6.21 (0.50)*** |
5.12 (0.55)*** |
| Random effects σ2 (SE) | |||||
| Intercept | 0.00 (0.06) | 0.00 (0.09) | 0.00 (0.03) | 0.01 (0.02) | 0.01 (0.01) |
| Residual | 0.23 (0.07) | 0.26 (0.10) | 0.15 (0.04) | 0.08 (0.02) | 0.07 (0.01) |
| Number of parameters | 5 | 6 | 6 | 6 | 8 |
| Model comparison | |||||
| AIC | 140.31 | 136.42 | 87.73 | 41.62 | 26.11 |
| Likelihood ratio (χ2)a | – | 5.88* | 54.57* | 100.69*** | 120.20*** |
| Marginal R2 | 0.28 | 0.31 | 0.52 | 0.70 | 0.75 |
| Conditional R2 | 0.28 | 0.31 | 0.52 | 0.73 | 0.79 |
Unstandardized fixed and random effects and model fit statistics for five multilevel models predicting change in resting heart rate (bpm) from change in sleep patterns. Model 1 represents the baseline model while Models 2–4 included additional predictors for sleep duration (Model 2), change in midsleep time (Model 3) and change in midsleep variability (Model 4) factors. Finally, Model 5 included all three additional predictors to assess the independent contributions of each predictor in the model.
SE, standard error; AIC, Akaike information criterion.
aLikelihood ratio value is based on comparison to Model 1.
*P < .05; **P < .01; ***P < .001.