Table 4.

The difference of urinary cortisol level by working time and shift cycles (unit: μg/dL).

Shift Cycle	N	uC1	uC2/uC3	uC4	uC5	p
		GM ± GSD	GM ± GSD	GM ± GSD	GM ± GSD
3	57	1.33 ± 0.90	1.31 ± 1.75			0.884
6	51	1.34 ± 0.84	1.14 ± 1.02			0.280
9	60	1.39 ± 0.80	1.16 ± 0.97			0.173
21	123	1.38 ± 0.96	0.98 ± 0.85			0.001
Total	291	1.37 ± 0.89	1.12 ± 0.89			0.001
	p	0.985	0.133
	p †	0.867	0.093
21	61	1.34 ± 0.85		1.06 ± 1.02		0.112
6	42	1.42 ± 0.79			0.95 ± 1.31	0.050
9	54	1.38 ± 0.83			1.43 ± 1.05	0.766
21	121	1.37 ± 0.95			1.04 ± 1.04	0.011
Total	217	1.39 ± 0.89			1.13 ± 1.11	0.007
	p	0.963			0.052
	p †	0.799			0.051

^†p-value after adjustment for gender, age, chronotype, depression, job, PSTD, sleep disorder, fatigue, caffeine intake, subjective health condition, sleep quality. uC1: urinary cortisol during night sleep after day work. uC2: urinary cortisol during night work. uC3: urinary cortisol during 24 h work. uC4: urinary cortisol during the day sleep right after the night duty. uC5: urinary cortisol during night sleep in the next day after night work.