Table 2. PHQ-9 item level values and item-total correlations (n=230).

PHQ-9	Mean	SD	Item-total correlation
(1) Little interest or pleasure in doing things	0.91	0.67	0.63
(2) Feeling down, depressed, or hopeless	0.85	0.59	0.59
(3) Trouble falling or staying asleep, or sleeping too much	0.60	0.82	0.54
(4) Feeling tired or having little energy	0.86	0.71	0.69
(5) Poor appetite or overeating	0.67	0.82	0.63
(6) Feeling bad about yourself—or that you are a failure	0.77	0.78	0.66
(7) Trouble concentrating on things	1.07	0.90	0.61
(8) Moving or speaking so slowly that other people could have noticed	0.47	0.74	0.58
(9) Thoughts that you would be better off dead or of hurting yourself	0.18	0.48	0.55

PHQ-9=Patient Health Questionnaire, SD=standard deviation.