Validity of PHQ-9 Compared With the CIDI and the Posttest Probabilities
Threshold Score for PHQ-9 | Sensitivity | Specificity | LR+ | 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. | ||||||
≥8 | 0.82 (134/163) | 0.85 (2,111/2,479 | 5.8 | 0.16 | 27 | 1.0 |
≥10 | 0.74(121/163) | 0.91 (2,259/2,479) | 8.4 | 0.28 | 36 | 1.8 |
≥12 | 0.61(100/163) | 0.94 (2,336/2,479) | 10.6 | 0.44 | 41 | 2.6 |
≥15 | 0.45 (73/163) | 0.97 (2,415/2,479) | 17.3 | 0.57 | 53 | 3.6 |
PHQ major depression8, c | 0.45 (73/163) | 0.97 (2,405/2,479) | 15.0 | 0.57 | 50 | 3.6 |