Table 2.

Comparison of melatonin and sleepiness between the two night shifts.

Variables	7-night shift	4-night shift	P value
melatonin 1	5.71 ± 3.00	6.21 ± 2.80	0.503‡
melatonin 2	10.61 ± 5.62	8.67 ± 4.00	0.103‡
melatonin 3	16.24 ± 6.76	26.35 ± 9.81	<0.001‡
melatonin 4	21.57 ± 7.92	15.07 ± 5.80	<0.001
Overall Melatonin changes	17.3 ± 7.90	9.77 ± 5.70	<0.001
Sleepiness 1	2.86 ± 1.09	2.48 ± 0.57	0.104‡
Sleepiness 2	3.13 ± 1.17	1.23 ± 1.36	0.684‡
Sleepiness 3	4.30 ± 1.15	6.63 ± 1.59	0.049‡
Sleepiness 4	6.50 ± 2.39	5.60 ± 2.01	0.273‡
Sleepiness changes	4.62 ± 2.54	4.14 ± 2.2	0.442