Table 3. Proportional Hazards Regression Analysis by Positive Response for Each Item on the Primary Care–Posttraumatic Stress Disorder Screena .
| Model | Positive PC-PTSD response, baseline HR (95% CI) | Interaction between item 4 and timeb | HR over time for item 4 (95% CI) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Item 1 | Item 2 | Item 3 | Item 4 | β (SE) | P value | Day 1 | Day 30 | Day 365 | Day 500 | ||
| 1: Unadjusted | 0.95 (0.76-1.17) | 1.14 (0.91-1.44) | 0.91 (0.75-1.10) | 2.17 (1.61-2.93) | −0.0007 (0.0003) | .009 | 2.17 (1.61-2.92) | 2.12 (1.59-2.83) | 1.67 (1.36-2.06) | 1.52 (1.23-1.88) | |
| 2: Adjusted for age and sex | 0.94 (0.76-1.17) | 1.17 (0.93-1.48) | 0.89 (0.73-1.09) | 2.19 (1.62-2.96) | −0.0007 (0.0003) | .008 | 2.18 (1.62-2.96) | 2.14 (1.60-2.86) | 1.68 (1.36-2.07) | 1.52 (1.23-1.89) | |
| 3: Adjusted for all demographic characteristics | 0.99 (0.80-1.22) | 1.22 (0.97-1.54) | 0.93 (0.76-1.13) | 2.15 (1.59-2.90) | −0.0007 (0.0003) | .007 | 2.15 (1.59-2.90) | 2.10 (1.58-2.81) | 1.65 (1.34-2.03) | 1.50 (1.21-1.85) | |
| 4: Adjusted for demographic characteristics and mental health diagnoses | 0.93 (0.76-1.14) | 1.17 (0.94-1.46) | 0.90 (0.74-1.08) | 1.76 (1.31-2.36) | −0.0007 (0.0003) | .007 | 1.76 (1.31-2.36) | 1.72 (1.30-2.28) | 1.35 (1.11-1.64) | 1.22 (1.00-1.50) | |
| 5: Adjusted for demographic characteristics, mental health diagnoses, treatment, and suicide attempts | 0.92 (0.75-1.12) | 1.17 (0.94-1.45) | 0.90 (0.75-1.08) | 1.70 (1.27-2.29) | −0.0007 (0.0003) | .007 | 1.70 (1.27-2.28) | 1.67 (1.26-2.21) | 1.31 (1.07-1.59) | 1.18 (0.97-1.45) | |
Abbreviations: HR, hazard ratio; PC-PTSD, Primary Care–Posttraumatic Stress Disorder Screen.
a
Includes 1 693 449 total screens.
b
Interaction between item 4 and time was the only interaction term included in the final models because none of the other items had significant results in any of the models performed.