Table A2.
Raw Score to T Score Conversion Table (IRT Fixed-Parameter Calibration Linking) for PHQ-9 to PROMIS Depression
| PHQ-9 score | PROMIS Depression T score | SE | PHQ-9 score | PROMIS Depression T score | SE |
|---|---|---|---|---|---|
| 0 | 37.4 | 6.4 | 14 | 64.7 | 3.2 |
| 1 | 42.7 | 5.3 | 15 | 65.8 | 3.2 |
| 2 | 45.9 | 4.8 | 16 | 66.9 | 3.2 |
| 3 | 48.3 | 4.7 | 17 | 68.0 | 3.1 |
| 4 | 50.5 | 4.3 | 18 | 69.2 | 3.2 |
| 5 | 52.5 | 4.0 | 19 | 70.3 | 3.2 |
| 6 | 54.2 | 3.8 | 20 | 71.5 | 3.2 |
| 7 | 55.8 | 3.7 | 21 | 72.7 | 3.3 |
| 8 | 57.2 | 3.6 | 22 | 74.0 | 3.4 |
| 9 | 58.6 | 3.5 | 23 | 75.3 | 3.5 |
| 10 | 59.9 | 3.4 | 24 | 76.7 | 3.6 |
| 11 | 61.1 | 3.3 | 25 | 78.3 | 3.7 |
| 12 | 62.3 | 3.3 | 26 | 80.0 | 3.8 |
| 13 | 63.5 | 3.2 | 27 | 82.3 | 3.8 |
Note. IRT = item response theory; PHQ-9 = 9-item Patient Health Questionnaire; PROMIS Depression = Depression subscale of the Patient-Reported Outcomes Measurement Information System.