Table 4. The sleep quality score and their different components in normal and over-used students .

Components	Overall Score		Normal		Over-used		P value
	Mean	SD	Mean	SD	Mean	SD
Subjective sleep quality score	0.99	0.75	0.93	0.71	1.50	0.88	0.001
Sleep latency Score	1.05	0.81	1.04	0.79	1.17	0.91	0.310
Sleep duration score	1.00	0.79	1.01	0.78	0.90	0.88	0.380
Habitual sleep efficiency score	0.06	0.34	0.05	0.30	0.15	0.54	0.257
Sleep disturbances score	1.70	0.53	1.03	0.52	1.33	0.53	0.002
Use of sleeping medication score	0.16	0.51	0.13	0.48	0.33	0.70	0.025
Daytime dysfunction score	0.97	0.89	0.90	0.87	1.48	0.91	0.001
Sleep quality Score	5.30	2.35	5.10	2.24	6.90	2.60	0.001