Table 4.

Group differences between subjects high and low on nocturnal cognitive arousal on objective sleep disturbances on the baseline night.

	Low Cognitive Arousal n=43/52	High Cognitive Arousal n=9/52
Sleep latency	20.74±19.89	57.56±44.64	t(50)=3.94***, d=1.07
Latency to persistent sleep	27.14±21.11	72.44±44.17	t(50)=4.72***, d=1.31
Wake after sleep onset	36.83±43.91	81.28±79.10	t(50)=2.37**, d=.69
Sleep efficiency	86.97±12.38	71.06±17.74	t(50)=−3.24**, d=1.04
Total sleep time	6.95±.98 hrs	5.70±1.44 hrs	t(50)=−3.17**, d=1.01
MSLT latency	12.12±4.28 mins	15.51±4.18 mins	t(50)=2.18*, d=.80

Note: Cognitive arousal was assessed via the Presleep Arousal Scale – Cognitive factor (PSAS-C). Low Cognitive Arousal was defined as baseline PSAS-C scores ≤ 16. High Cognitive Arousal was defined as baseline PSAS-C scores > 16. Sleep latency, Sleep latency (persistent), Wake after sleep onset, Sleep efficiency (Total Sleep Time/Time in Bed), and Total Sleep Time were assessed via polysomnography. Means and Standard Deviations are reported for objective findings. t = t-statistics for independent samples t-tests.

^*p<.05.

^**p<.01.

^***p<.001.

p = significance value for non-significant results. d = Cohen’s d effect size for independent samples t-tests.