PHQ-9 items as predictors of pain and disability MCID achievement.
| PHQ-9 Items | OR | 95% CI | P Valuea,b |
| VAS neck MCID | |||
| Question 1 | 1.2 | (0.7, 2.2) | 0.550 |
| Question 2 | 1.2 | (0.6, 2.3) | 0.667 |
| Question 3 | 2.0 | (1.0, 3.9) | 0.045 |
| Question 4 | 1.2 | (0.6, 2.3) | 0.594 |
| Question 5 | 0.8 | (0.4, 1.6) | 0.489 |
| Question 6 | 0.9 | (0.4, 1.8) | 0.741 |
| Question 7 | 0.9 | (0.5, 1.7) | 0.758 |
| Question 8 | 0.6 | (0.3, 1.4) | 0.271 |
| Question 9b | - | - | - |
| Question 10 | 1.1 | (0.5, 2.2) | 0.843 |
| Overall PHQ-9 score | 1.0 | (0.9, 1.1) | 0.971 |
| VAS arm MCID | |||
| Question 1 | 1.2 | (0.7, 2.1) | 0.434 |
| Question 2 | 1.0 | (0.6, 1.7) | 0.949 |
| Question 3 | 1.7 | (1.0, 2.9) | 0.049 |
| Question 4 | 1.0 | (0.6, 1.7) | 0.975 |
| Question 5 | 0.6 | (0.3, 1.2) | 0.180 |
| Question 6 | 0.7 | (0.3, 1.3) | 0.240 |
| Question 7 | 0.9 | (0.5, 1.6) | 0.699 |
| Question 8 | 0.8 | (0.4, 1.7) | 0.560 |
| Question 9b | - | - | - |
| Question 10 | 0.8 | (0.4, 1.4) | 0.396 |
| Overall PHQ-9 score | 1.0 | (0.9, 1.1) | 0.683 |
| Neck Disability Index MCID | |||
| Question 1 | 1.9 | (0.9, 3.7) | 0.060 |
| Question 2 | 1.3 | (0.7, 2.5) | 0.415 |
| Question 3 | 1.6 | (0.9, 2.8) | 0.110 |
| Question 4 | 1.6 | (0.8, 3.0) | 0.153 |
| Question 5 | 1.2 | (0.6, 2.3) | 0.694 |
| Question 6 | 1.5 | (0.6, 3.4) | 0.348 |
| Question 7 | 1.4 | (0.7, 2.9) | 0.322 |
| Question 8 | 1.1 | (0.5, 2.5) | 0.825 |
| Question 9b | - | - | - |
| Question 10 | 2.0 | (0.8, 4.6) | 0.117 |
| Overall PHQ-9 score | 1.1 | (0.9, 1.2) | 0.291 |
Abbreviations: MCID, minimum clinically important difference; PHQ, Patient Health Questionnaire; VAS, visual analog scale.
Note: Boldface indicates statistical significance.
↵a P values calculated using logistic regression to assess each question as a predictor of MCID achievement.
↵b Unable to assess question 9 due to the limited number of patients with affirmative responses.