Table 3. Pearson Correlation Coefficient matrix between severity of depression, anxiety, and stress and sleep quality and its components.

Variable	Depression	Anxiety	Stress	Sleep quality
Subjective sleep quality	0.33**	0.36**	0.42**	0.77**
Sleep latency	0.00	0.01	0.08**	0.75**
Sleep duration	0.02	0.03	0.05	0.63**
Sleep disturbance	0.06*	0.05	0.13**	0.81**
Use of sleep medication	0.31**	0.33**	0.34**	0.73**
Daytime dysfunction	0.40**	0.34**	0.43**	0.78**
Sleep efficiency	0.23**	0.30**	0.29**	0.66**
Total sleep quality	0.20**	0.21**	0.28**	1
M	18.77	17.76	18.89	4.55
SD	10.15	9.95	9.60	3.43

Note: SD=Standard Deviation, M=Mean, *P<0.05, **P<0.001