Effects of Between- and Within-Subject Variability on Autonomic Cardiorespiratory Activity during Sleep and Their Limitations on Sleep Staging: A Multilevel Analysis

Table 1

Subject demographics and sleep statistics ().

	Mean ± SD	Range
Gender (77 men and 88 women)
Age, y	51.8 ± 19.4	20–95
BMI, kg⋅m^−2	24.6 ± 3.5	17.0–35.3
Total recording time, h	7.8 ± 0.5	6.0–9.3
Wake, %	22.7 ± 13.2	1.2–78.6
REM sleep, %	13.6 ± 5.3	0–26.5
Light sleep, %	52.3 ± 10.0	15.6–72.1
Deep sleep, %	11.4 ± 6.6	0–28.5