Table 2.

Validity and reliability of the Korean version of the PHQ-9 and GAD-7 scales

Questionnaires		Validity				Reliability
items		Factor loading	Communality	Eigenvalue	Variance (%)	Cronbach’s alpha
PHQ-9				4.607	51.186	0.870
	Item 1 Anhedonia	0.720	0.519
	Item 2 Depressed or hopeless	0.797	0.635
	Item 3 Sleep changes	0.639	0.408
	Item 4 Fatigue or loss of energy	0.699	0.489
	Item 5 Appetite changes	0.664	0.441
	Item 6 Worthlessness or guilt	0.738	0.545
	Item 7 Trouble concentrating on things	0.743	0.551
	Item 8 Psychomotor agitation or retardation	0.734	0.539
	Item 9 Suicidal ideation	0.693	0.481
GAD-7				4.797	68.531	0.919
	Item 1 Felling nervous, anxious, or on edge	0.853	0.728
	Item 2 Not being able to stop or control worrying	0.849	0.720
	Item 3 Worrying too much	0.816	0.666
	Item 4 Trouble relaxing	0.862	0.744
	Item 5 Being so restless	0.848	0.719
	Item 6 Becoming easily annoyed or irritable	0.752	0.566
	Item 7 Feeling afraid as if something awful might happen	0.808	0.654

PHQ-9, Patient Health Questionnaire 9-item scale; GAD-7, Generalized Anxiety Disorder 7-item scale