Table 1. Age and status of napping before, during, and after work.

Variable	Group		p-value
	No nap (n=7)	Nap (n=8)
Age (yr)	23.71 (1.88)	23.00 (0.92)	0.46
Nap time before night shift (h)	2.07 (1.17)	3.71 (2.33)	0.30
Nap time while on night shift (min)	61.88 (5.30)	60.00 (15.00)	0.88
Sleep time during the day following a night shift (h)	3.28 (1.21)	3.13 (1.66)	0.95

Values are expressed as means (SD) in each category. Differences were evaluated by the Mann-Whitney U test.