Sleep Spindles Characteristics in Insomnia Sufferers and Their Relationship with Sleep Misperception

Table 5

Summary of multiple regression analysis for overestimation (Misperception Index < 0).

Variable	B	SE	Beta
Intercept
Stage 2 sleep spindles
Number	0.000	0.000
Density	0.059	0.078
Duration	0.135	0.238
Frequency		0.057
Amplitude	0.002	0.002
SWS sleep spindles
Number		0.001
Density		0.027	1.482
Duration		0.184	0.112
Frequency		0.029	0.054
Amplitude		0.002
Objective sleep measures
SOL (min)	0.002	0.002	0.314
WASO (min)	0.001	0.002	0.329
TST (min)	0.001	0.002	0.718
SE (%)	0.006	0.012	0.580
Stage 1 (min)		0.025
Stage 1 (%)	0.169	0.100	7.587
Stage 2 (min)	—	—	—
Stage 2 (%)	—	—	—
Stage SWS (min)		0.011	−5.435
Stage SWS (%)	0.071	0.047	6.243
REM (min)		0.200
REM (%)	0.008	0.005

Note. = ; = .  B: unstandardized regression coefficient; SE: standard error of the coefficient; beta: standardized coefficient. SOL: sleep onset latency. WASO: wake after sleep onset. TST: total sleep time. SE: sleep efficiency. SWS: slow wave sleep. REM: rapid eye movement.