Table 4.

Counts (percent of each group) of participants from each group that had MSLT naps containing each sleep stage

	Control	PTSD	Chi-squared	p
	Count (%)	Count (%)
Stage 1	47 (100.0)	37 (100.0)	-	-
Stage 2	29 (67.1)	22 (59.5)	0.044	>0.999
SWS	0 (0.0)	0 (0.0)	-	-
REM	4 (8.5)	4 (10.8)	0.127	0.727
Multiple naps with REM	2 (4.3)	1 (2.7)	0.145	>0.999

SWS = Slow wave sleep; REM = rapid eye movement sleep; PTSD = posttraumatic stress disorder