The validity of the Patient Health Questionnaire for screening depression in chronic care patients in primary health care in South Africa

Table 3 Item-level discrimination PHQ-9 (N = 676)

Item	Item-test correlation	Item-rest correlation	Average Inter-item covariance	Item Alpha
Phq1	0.578	0.429	0.144	0.734
Phq2	0.649	0.491	0.133	0.724
Phq3	0.619	0.440	0.135	0.734
Phq4	0.655	0.509	0.133	0.721
Phq5	0.620	0.451	0.135	0.732
Phq6	0.602	0.465	0.142	0.723
Phq7	0.587	0.466	0.147	0.730
Phq8	0.347	0.250	0.170	0.757
Phq9	0.546	0.420	0.150	0.736
Overall			0.143	0.756

ISSN: 1471-244X