Table 3.

Results of multivariate regression analysis of irregular bedtime frequency and average daily sleep time on PSQI, ESS, and FSS scores

	ESS	FSS	PSQI
Intermediate FIB (p-value)	(0.389)	(0.132)	(0.02*)
Zero-order r	-0.05	0.05	0.05
Partial r	0.07	0.12	0.18
High FIB (p-value)	(0.015*)	(0.124)	(0.05*)
Zero-order r	0.18	0.09	0.20
Partial r	0.19	0.12	0.15
ADST (p-value)	(0.314)	(0.359)	(<0.001*)
Zero-order r	0.02	-0.11	-0.59
Partial r	0.08	-0.07	0.56
Total r (p-value)	0.20	0.17	0.61
	(0.09)	(0.196)	(<0.001*)

FIB, frequency of irregular bedtime; ADST, average daily sleep time; ESS, Epworth Sleepiness Scale; FSS, Fatigue Severity Scale; PSQI, Pittsburgh Sleep Quality Index; r, correlation coefficients.

The multivariate regression analysis was performed by setting the intermediate and high FIB groups as dummy variables in comparison to the low FIB group

*p < 0.05