Table 3.

Validity of PHQ-9 Compared With the CIDI and the Posttest Probabilities

Threshold Score for PHQ-9SensitivitySpecificityLR+LR−PTL+a %PTL−b %
LR+=positive likelihood ratio; LR−=negative likelihood ratio; PTL+ = posttest likelihood of a positive test; PTL+ = posttest likelihood of a negative test; PHQ-9 = 9-item Patient Health Questionnaire.
a Positive predictive value.
b 1 – Negative predictive value.
c The original scoring system created by Spitzer et al in 19996 requires a score of 2 or higher on at least 1 of the first 2 questions and then a minimum score of 2 or higher on 5 of the questions for a diagnosis of PHQ major depression.
≥80.82 (134/163)0.85 (2,111/2,4795.80.16271.0
≥100.74(121/163)0.91 (2,259/2,479)8.40.28361.8
≥120.61(100/163)0.94 (2,336/2,479)10.60.44412.6
≥150.45 (73/163)0.97 (2,415/2,479)17.30.57533.6
PHQ major depression8, c0.45 (73/163)0.97 (2,405/2,479)15.00.57503.6