Table 4.

Comparison of the polysomnography findings according to the caffeine therapy.

Sleep Variables	Caffeine (−)	Caffeine (+)	P a
	(n = 16)	(n = 12)
Total recording time, min	108.8 [69.7–157.8]	89.1 [74–148.5]	.85
WASO, min	17.8 [7.2–34.4]	16.9 [11.1–37]	.85
Total sleep time, min	81.5 [51–116]	68.3 [49.8–95.8]	.50
Sleep latency, min	4.5 [2–8.2]	7.5 [2.8–11.5]	.35
Sleep efficiency, %	78.7 [67.4–84.3]	68.2 [57.8–80.4]	.21

Data are represented as median [interquartile range]. ^aMann–Whitney U test. WASO = wake after sleep onset.