Table 3.
Associations of MVC characteristics, pre-MVC lifetime histories of Probable PTSD and MDE, peritraumatic symptoms, and 2-week disorders with 3-month Probable PTSD and/or MDE (n=1,306)†
| Model 1 |
Model 2‡ |
Model 3§ |
Model 4¶,†† |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| % | (SE) | RR | (95% CI) | RR | (95% CI) | RR | (95% CI) | RR | (95% CI) | |
|
|
||||||||||
| I. MVC characteristics | ||||||||||
| Severe pain in ED‡‡ | 41.0 | (1.4) | 1.4* | (1.2–1.8) | 1.4* | (1.1–1.7) | 1.3* | (1.0–1.6) | 1.3* | (1.1–1.6) |
| II. Joint pre-MVC histories of PTSD and/or MDE | ||||||||||
| Both lifetime and ≥1 30-day | 9.5 | (0.8) | 6.9* | (5.0–9.6) | 6.3* | (4.5–8.8) | 2.9* | (2.0–4.2) | 3.2* | (2.2–4.6) |
| Both lifetime and neither 30-day | 10.4 | (0.8) | 4.5* | (3.1–6.4) | 4.3* | (3.0–6.2) | 2.6* | (1.8–3.8) | 2.7* | (1.9–4.0) |
| PTSD-alone: lifetime (with or without 30-day)§§ | 23.7 | (0.9) | 3.9* | (2.9–5.4) | 3.7* | (2.7–5.1) | 2.4* | (1.7–3.3) | 2.4* | (1.8–3.4) |
| MDE-alone: lifetime (with or without 30-day)§§ | 4.7 | (1.0) | 2.6* | (1.5–4.7) | 2.6* | (1.4–4.6) | 2.1* | (1.2–3.6) | 2.1* | (1.2–3.7) |
| F4 | 36.2* | 30.1* | 9.7* | 11.7* | ||||||
| III. Peritraumatic symptomatology ¶¶ | ||||||||||
| Peritraumatic distress | 0.0 | (1.0) | - | - | 1.1††† | (0.9–1.2) | - | - | - | - |
| Peritraumatic dissociation††† | 0.0 | (1.0) | - | - | 1.0††† | (0.9–1.2) | - | - | - | - |
| F2 | - | - | - | - | ||||||
| IV. 2-week PTSD and/or MDE | ||||||||||
| a. PTSD‡‡‡ | ||||||||||
| PTSD | 37.4 | (1.3) | - | - | - | - | 3.4* | (2.3–4.9) | - | - |
| Subthreshold PTSD | 12.4 | (0.9) | - | - | - | - | 2.5* | (1.7–3.9) | - | - |
| F2 | - | - | 21.0* | - | ||||||
| b. MDE | ||||||||||
| MDE | 13.9 | (1.0) | - | - | - | - | 1.6* | (1.1–2.2) | - | - |
| Subthreshold MDE | 16.8 | (1.0) | - | - | - | - | 1.3 | (0.9–1.7) | - | - |
| F2 | - | - | 4.1* | - | ||||||
| F4 | - | - | 20.7* | - | ||||||
| c. Joint 2-week PTSD and/or MDE | ||||||||||
| Both (threshold or subthreshold) | 29.0 | (0.7) | - | - | - | - | - | - | 5.0* | (3.5–7.2) |
| PTSD-alone (threshold or subthreshold)§§ | 21.1 | (0.9) | - | - | - | - | - | - | 3.6* | (2.5–5.3) |
| MDE-alone (threshold or subthreshold)§§ | 2.1 | (0.4) | - | - | - | - | - | - | 3.7* | (1.8–7.8) |
| F3 | - | - | - | 25.5* | ||||||
| Total model F5,7,9,8 | 33.6* | 24.8* | 25.7* | 26.9* | ||||||
Significant at the .05 level, two-sided test.
Note. Estimates reflect multiply-imputed data (30 imputations).
Abbreviations. CI, confidence interval; ED, emergency department; MDE, major depressive episode; MVC, motor vehicle collision; PTSD, posttraumatic stress disorder; RR, relative risk.
To reduce redundancy, each survey-based assessment of Probable PTSD and MDE is referred to in the table and subsequent footnotes as “PTSD” and “MDE.” Based on modified Poisson regression models with robust variance estimates.
An interaction between peritraumatic stress and peritraumatic dissociation was not significant (F1=0.7, p=.41).
Interactions between the 2 PTSD terms and the 2 MDE terms at 2 weeks were significant (F4=4.2, p=.046). Inspection showed that RRs were very similar for patients with 2-week PTSD-alone (i.e., no MDE) and for those with 2-week MDE-alone (i.e., no PTSD), leading us to collapse the joint association into separate cells for either threshold or subthreshold. The distinction between threshold and subthreshold was nonsignificant both for PTSD (F1=1.2, p=.28) and MDE (F1=1.0, p=.35). However, RRs were considerably larger among patients with 2-week histories with overlapping PTSD and MDE diagnoses, so a third cell was created for these patients. The 3 dummy predictor variables defining these combinations, which left patients without any diagnosis as the reference category, captured the significant component of the associations between joint 2-week histories of PTSD and MDE with the outcome (F3=9.1, p<.001). The remainder of the joint association was nonsignificant (F5=1.5, p=.17).
The combined PARP (SE) for all four pre-MVC variables controlling MVC characteristics fell from 63.1% (3.3) in Table 2 to 46.8% (4.1) in Table 3.
See Appendix Table 5 for a re-estimation of the results in the current table controlling for between-ED variation in the outcome. As shown there, this variation was nonsignificant (F28=0.5, p=.98) and the results reported in the current table were unchanged when we examined pooled within-ED associations.
Although the linear pain score was significant, further analysis showed its association with the outcome to be nonlinear and to be well-captured by a dummy variable for a score in the top 40% of the observed distribution of patients with pain on the pain severity rating scale.
PTSD-alone indicates a diagnosis of PTSD and no diagnosis of MDE. MDE-alone indicates a diagnosis of MDE and no diagnosis of PTSD.
Both peritraumatic distress (RR=1.3, 95% CI=1.2–1.5, p<.001) and peritraumatic dissociation (RR=1.6, 95% CI=1.3–2.0, p<.001) were significant in univariable models, both became nonsignificant when controls were introduced for pre-MVC PTSD-MDE (Model 2).
This variable is continuous and standardized to a mean of 0 and a standard deviation of 1.
An earlier AURORA report used a PCL-5 modification to assess 2-week DSM-5 Acute Stress Disorder Criterion B rather than 2-week PTSD (Kessler, Ressler et al., 2020), but we instead used criteria for 2-week PTSD here to allow parallel analysis across all 3 follow-up assessments.