Table 2.

Differences for the Pittsburgh Sleep Quality Index items according to age grouping when the chi-square test was applied.

Age	Pittsburgh Sleep Quaility Index Item				Chi-Square (n, p-Value)
Sleep Latency
	5–15 min	16–30 min	31–60 min	>60 min	n = 1157 p < 0.001
18–40	7.2%	24.7%	34.1%	34.1%
>40	16.7%	35.6%	25.2%	22.5%
Sample %	10.8%	28.9%	30.7%	29.6%
Sleep Duration
	≥7 h	6 h	5 h	<5 h	n = 1157 p < 0.001
18–40	34.2%	27.3%	21.5%	17.0%
>40	39.4%	27.0%	25.2%	8.3%
Sample %	36.2%	27.2%	22.9%	13.7%
Sleep Quality
	Very good	Good	Bad	Very bad	n = 1157 p < 0.001
18–40	4.2%	37.0%	48.0%	10.8%
>40	18.2%	44.4%	31.1%	6.3%
Sample %	9.6%	39.8%	41.5%	9.1%
Sleep Efficiency
	≥85%	75 a 84%	65 a 74%	<65%	n = 1007 p < 0.003
18–40	31.7%	22.1%	19.2%	26.9%
>40	42.3%	20.6%	18.0%	19.1%
Sample %	35.7%	21.5%	18.8%	23.9%
Sleep Disorders
	Not during the past month	Less than once a week	Once or twice a week	Three or more times	n = 1157 p < 0.001
18–40	1.3%	66.9%	31.0%	0.8%
>40	4.1%	68.9%	24.8%	2.3%
Sample %	2.3%	67.7%	28.6%	1.4%
Sleep Medications
	Not during the past month	Less than one a week	Once or twice a week	Three or more times	n= 1157 p < 0.003
18–40	82.5%	6.9%	5.3%	5.3%
>40	74.8%	8.1%	6.3%	10.8%
Sample %	79.5%	7.3%	5.7%	7.4%
Daytime Dysfunction
	No problem at all	Very slight problem	Somewhat of a problem	A very big problem	n = 978 p < 0.001
18–40	12.1%	36.9%	45.6%	5.4%
>40	22.6%	46.9%	29.0%	1.5%
Sample %	16.3%	40.9%	39.0%	3.9%