Table 2.

Reliability of PHQ-9

PHQ-9 Items	PHQ-9 Questions	Scale Mean if Item Deleted	Corrected Item-Total Correlation	Cronbach’s Alpha if Item Deleted	Items Mean ± SD
PHQ-1	Little interest or fun in doing things	7.80	0.540	0.773	0.90 ± 1.08
PHQ-2	Feeling down, depressed or hopeless	7.34	0.602	0.764	1.36 ± 1.17
PHQ-3	Trouble falling asleep, staying asleep or sleeping too much	7.44	0.484	0.781	1.26 ± 1.23
PHQ-4	Feeling tired or having little energy	7.62	0.456	0.784	1.08 ± 1.15
PHQ-5	Poor appetite or overeating	7.66	0.494	0.779	1.04 ± 1.19
PHQ-6	Feeling bad about yourself, or that you’re a failure or have let yourself or your family down	7.57	0.456	0.784	1.13 ± 1.15
PHQ-7	Trouble concentrating on things such as reading the newspaper or watching television	7.68	0.522	0.775	1.02 ± 1.11
PHQ-8	Moving or speaking so slowly that other people could have noticed. Or the opposite	8.15	0.404	0.790	0.55 ± 0.97
PHQ-9	Thoughts that you would be better off dead or hurting yourself in some way	8.33	0.466	0.784	0.37 ± 0.82
Overall	Cronbach’s Alpha	0.799			8.65 ± 6.1