Table 5.

Sensitivity, specificity, Youden's index, likelihood ratios and predictive values at different cut-off scores of the PHQ-2, PHQ-9 and PHQ-8 when compared to the CIDI

Threshold Score for PHQ-2	Sensitivity	Specificity	Youden's index	LR +	LR−	PPV	NPV
⩾ 1	0.94	0.53	0.47	2.00	0.12	0.10	1.00
⩾ 2	0.88	0.70	0.57	2.89	0.18	0.13	0.99
⩾ 3	0.68	0.85	0.54	4.68	0.37	0.19	0.98
⩾ 4	0.55	0.92	0.47	6.63	0.49	0.24	0.97
Threshold Score for PHQ-8	Sensitivity	Specificity	Youden's index	LR +	LR-	PPV	NPV
⩾ 5	0.89	0.70	0.59	2.96	0.16	0.14	0.99
⩾ 6	0.89	0.76	0.65	3.74	0.15	0.17	0.99
⩾ 7	0.86	0.81	0.68	4.65	0.17	0.20	0.99
⩾ 8	0.80	0.85	0.65	5.47	0.24	0.23	0.99
⩾ 9	0.73	0.89	0.62	6.84	0.31	0.27	0.98
⩾ 10	0.70	0.91	0.62	7.89	0.32	0.30	0.98
⩾ 11	0.66	0.93	0.59	9.80	0.37	0.35	0.98
⩾ 12	0.64	0.95	0.59	13.70	0.38	0.42	0.98
⩾ 13	0.59	0.96	0.55	15.59	0.43	0.46	0.98
⩾ 14	0.52	0.97	0.50	19.44	0.49	0.51	0.97
⩾ 15	0.48	0.98	0.46	21.69	0.53	0.54	0.97
Threshold Score for PHQ-9	Sensitivity	Specificity	Youden's index	LR +	LR−	PPV	NPV
⩾ 5	0.94	0.64	0.59	2.65	0.09	0.10	1.00
⩾ 6	0.91	0.72	0.63	3.21	0.12	0.12	0.99
⩾ 7	0.86	0.78	0.64	3.89	0.18	0.14	0.99
⩾ 8	0.86	0.82	0.68	4.81	0.17	0.17	0.99
⩾ 9	0.80	0.86	0.66	5.55	0.23	0.19	0.99
⩾ 10	0.74	0.89	0.63	6.73	0.29	0.22	0.99
⩾ 11	0.69	0.90	0.59	7.16	0.35	0.23	0.99
⩾ 12	0.66	0.92	0.58	8.47	0.37	0.26	0.98
⩾ 13	0.60	0.94	0.54	9.90	0.43	0.30	0.98
⩾ 14	0.51	0.95	0.46	1.10	0.51	0.30	0.98
⩾ 15	0.49	0.96	0.44	11.45	0.54	0.33	0.98

Note. LR+, Positive Likelihood Ratio; LR−, Negative Likelihood Ratio; PPV, Positive Predictive Value; PPN, Negative Predictive Value. Bold shade indicate optimal cut-off value according to Youden´s index for PHQ-2, PHQ-8 and PHQ-9.