Table S2.

Comparison of each PHQ-9 items in early COPD subjects with or without depression^a

PHQ-9 items	Without depression (N=181)	With depression (N=30)	P-value
PHQ1 (little interest or pleasure in doing things)	0.11±0.42	1.0±1.1	<0.01
PHQ2 (feeling down, depressed, or hopeless)	0.77±0.90	0.06±0.23	<0.01
PHQ3 (trouble falling or staying asleep, or sleeping too much)	0.23±0.59	1.6±1.16	<0.01
PHQ4 (feeling tired or having little energy)	0.29±0.61	1.7±1.06	<0.01
PHQ5 (poor appetite or overeating)	0.11±0.46	0.70±0.99	<0.01
PHQ6 (feeling bad about yourself, or that you are a failure or have let yourself or your family down)	0.07±0.32	1.03±1.07	<0.01
PHQ7 (trouble concentrating on things, such as reading the newspaper or watching television)	0.07±0.29	0.43±0.94	<0.01
PHQ8 (moving or speaking so slowly that other people could have noticed, or the opposite, being so fidgety or restless that you have been moving around a lot more than usual)	0.02±0.17	0.30±0.65	<0.01
PHQ9 (thoughts that you would be better off dead or hurting yourself in some way)	0.01±0.10	0.37±0.72	<0.01
Total score	0.97±1.25	7.90±3.96	<0.01

Note:

^aData are presented as mean ± SD.

Abbreviation: PHQ-9, Patient Health Questionnaire-9.