Table 4. Comparison of Sensitivity and Specificity Estimates and Number of Participants Requiring Full PHQ-9 for PHQ-2 Alone, PHQ-2 in Combination With PHQ-9, and PHQ-9 Alone Among 44 Studies (No. of Participants = 10 627; No. of Participants With Major Depression = 1361) That Used a Semistructured Reference Standard and Had Both PHQ-2 and PHQ-9 Item Scores Availablea.
| Screening strategy | |||||
|---|---|---|---|---|---|
| PHQ-2 score ≥2 alone | PHQ-2 score ≥3 alone | PHQ-2 score ≥2 then PHQ-9 score ≥10 | PHQ-2 score ≥3 then PHQ-9 score ≥10 | PHQ-9 score ≥10 alone | |
| PHQ-2 | |||||
| Administered, No. | 10 627 | 10 627 | 10 627 | 10 627 | |
| Positive screens, No. (%) | 4529 (42.6) | 2650 (24.9) | 4529 (42.6) | 2650 (24.9) | |
| PHQ-9 | |||||
| Administered, No. (%) | 4529 (42.6) | 2650 (24.9) | 10 627 (100.0) | ||
| Positive screens, No. (%) | 2461 (23.2) | 1946 (18.3) | 2655 (25.0) | ||
| Sensitivity and specificity (95% CI) | |||||
| Sensitivity | 0.92 (0.88 to 0.95) | 0.72 (0.67 to 0.77) | 0.82 (0.76 to 0.86) | 0.70 (0.64 to 0.75) | 0.86 (0.80 to 0.90) |
| Specificity | 0.67 (0.63 to 0.70) | 0.85 (0.83 to 0.87) | 0.87 (0.84 to 0.89) | 0.91 (0.89 to 0.93) | 0.85 (0.82 to 0.87) |
| Difference in accuracy estimates (each strategy – PHQ-9 alone) (95% CI) | |||||
| Sensitivity | 0.06 (0.01 to 0.11) | –0.13 (–0.20 to –0.09) | –0.04 (–0.09 to 0.01) | –0.16 (–0.23 to –0.12) | |
| Specificity | –0.18 (–0.21 to –0.16) | 0.01 (–0.02 to 0.03) | 0.02 (0.00 to 0.03) | 0.06 (0.04 to 0.08) | |
Abbreviation: PHQ, Patient Health Questionnaire.
a
Among the 48 PHQ-2 studies that used a semistructured reference standard, 4 studies did not have PHQ-9 item scores available and thus could not be included in the comparison of screening strategies.