Table 3.
Odds ratio for depression according to GOLD stage, CAT score, and comorbidity

		Depression (PHQ-9 score≥10)		OR (95% CI)
		No	Yes
		GOLD stage	Mild to moderate		49 (56.3)	4 (40.0)	1.00 (Referent)
	Severe to very severe	38 (43.7)	6 (60.0)	1.93 (0.51, 7.34)
CAT score	≤19	68 (78.2)	3 (30.0)	1.00 (Referent)
	20~29	16 (18.4)	4 (40.0)	5.67 (1.15, 27.87)
	≥30	3 (3.5)	3 (30.0)	22.66 (3.15, 63.19)
Comorbidity	0	69 (79.3)	7 (70.0)	1.00 (Referent)
	≥1	18 (20.7)	3 (30.0)	1.64 (0.39, 6.99)

PHQ-9, Patient Health Questionnarie-9; CAT, COPD assessment test.