Table 3. Regression coefficients of influence of parameters of sleep-wake cycle on sleep quality (N=147).

Variable		Unadjusted			Adjusted
		β	95% CI	p	β	95% CI	p
Age
	21–30 yr	Reference			Reference
	31–40 yr	0.05	−0.98 to 1.83	0.551	0.06	−1.20 to 2.29	0.536
Marital status
	Single	Reference			Reference
	Married	0.07	−1.19 to 2.79	0.797	0.08	−1.21 to 3.13	0.382
Educational background
	Junior college	Reference			Reference
	University or above	−0.12	−1.75 to 0.26	0.145	-0.05	−1.36 to 0.78	0.593
Years of service
	<2 yr	Reference			Reference
	2–5 yr	0.19	0.01 to 2.43	0.048	0.14	−0.29 to 2.14	0.133
	>5 yr	0.05	−0.91 to 1.52	0.619	−0.02	−1.62 to 1.38	0.877
Shift type
	Day	Reference			Reference
	Evening	−0.06	−1.54 to 0.76	0.506	−0.05	−1.48 to 0.85	0.597
	Night	0.08	−0.72 to 1.86	0.385	−0.01	−1.45 to 1.28	0.903
I<O		−0.29	−1.28 to 0.37	<0.001	−0.26	−1.24 to −0.23	0.004

β: standardized regression coefficient; CI: confidence interval; I<O: dichotomy index.