Effects of Between- and Within-Subject Variability on Autonomic Cardiorespiratory Activity during Sleep and Their Limitations on Sleep Staging: A Multilevel Analysis
Table 4
Coefficients and their standard errors (SE) of the optimized multilevel model without the between-subject centering effect (Model #1) for the six cardiorespiratory parameters analyzed in this study.
Model coef.
Respiratory parameters
Cardiac parameters
BR, ln-Hz
SDBR, ln-Hz
HR, ln-bpm
SDNN, ln-ms
LF, nu
HF, nu
Fixed
Coefficient (SE)
−1.458 (0.087)
−3.320 (0.032)
4.221 (0.016)
4.823 (0.255)
0.464 (0.014)
0.535 (0.027)
Baseline
Baseline
Baseline
Baseline
Baseline
Baseline
βREM
0.002 (0.008)NS
−0.205 (0.026)
−0.028 (0.001)
−0.104 (0.027)
0.030 (0.007)
−0.037 (0.007)
βlight
−0.035 (0.008)
−0.611 (0.026)
−0.061 (0.001)
−0.052 (0.021)
−0.027 (0.006)
0.039 (0.006)
βdeep
−0.044 (0.010)
−0.997 (0.033)
−0.055 (0.001)
−0.249 (0.026)
−0.096 (0.008)
0.106 (0.008)
−0.009 (0.002)
−0.002 (0.001)
0.042 (0.021)
−0.247 (0.069)
−0.045 (0.018)
0.052 (0.017)
0.011 (0.004)
−0.025 (0.011)
0.001 (0.0004)
−0.0001 (0.2e − 4)
0.001 (0.0002)
0.0004 (0.0001)
−0.0004 (0.0001)
−1.0e − 5 (0.3e − 5)
−2.8e − 5 (1.3e − 5)
−1.7e − 5 (0.5e − 5)
1.7e − 5 (0.5e − 5)
Random
Coefficient (SE)
Ω0
Ωwake
0.030 (0.003)
0.159 (0.018)
0.018 (0.002)
0.224 (0.025)
0.018 (0.002)
0.014 (0.002)
ΩREM
0.029 (0.003)
0.171 (0.020)
0.019 (0.002)
0.280 (0.031)
0.022 (0.002)
0.018 (0.002)
Ωlight
0.030 (0.003)
0.219 (0.024)
0.020 (0.002)
0.256 (0.028)
0.019 (0.002)
0.017 (0.002)
Ωdeep
0.031 (0.003)
0.257 (0.029)
0.020 (0.002)
0.324 (0.036)
0.020 (0.002)
0.017 (0.002)
1.2e − 7 (0.1e − 7)
6.6e − 7 (0.8e − 7)
3.5e − 8 (0.4e − 8)
7.2e − 7 (0.8e − 7)
5.0e − 8 (0.6e − 8)
4.6e − 8 (0.5e − 8)
Residual
0.019 (0.0001)
0.290 (0.001)
0.003 (0.00001)
0.230 (0.001)
0.033 (0.0001)
0.033 (0.0001)
Deviance
−150487
217253
−398075
186380
−75029
−74306
Note: ln, natural logarithm; nu, normalized unit; NS, not significant. The statistically significant effects (Wald -test, ), the fixed constant intercept , and sleep stage intercepts are presented.