Table 3.
Cox Regression Results Predicting Symptom Duration from Single Predictors (n = 162)
| HR | 95% CI | p | HR | 95% CI | p | ||
|---|---|---|---|---|---|---|---|
| Demographics and injury | Performance measures | ||||||
| Female gender | 0.84 | (.55, 1.28) | 0.422 | mBESS incomplete | 0.53 | (0.34, 0.82) | 0.004 |
| Age (years) | 0.98 | (.96, 1.01) | 0.262 | mBESS total score | 0.86 | (0.66, 1.12) | 0.273 |
| Race (black v. white) | 0.77 | (.49, 1.21) | 0.252 | SAC total score | 1.05 | (0.84, 1.32) | 0.648 |
| WTAR standard score | 1.01 | (.81, 1.26) | 0.924 | ANAM (n = 83) | |||
| House SES (Hollingshead) | 1.01 | (.99, 1.03) | 0.654 | Composite | 1.49 | (1.08, 2.06) | 0.016 |
| Health insurance | 0.497 | SRT | 1.48 | (1.02, 2.16) | 0.039 | ||
| None (v. Govt.) | 1.21 | (.64, 2.30) | 0.554 | CDS | 1.31 | (0.98, 1.76) | 0.065 |
| Commercial (v. Govt.) | 1.34 | (.82, 2.19) | 0.237 | PRT | 1.40 | (0.98, 2.01) | 0.068 |
| ADHD | 1.20 | (.55, 2.60) | 0.651 | MTH | 1.11 | (0.82, 1.49) | 0.514 |
| Migraine history | 0.68 | (.38, 1.24) | 0.209 | M2S | 1.27 | (0.96, 1.68) | 0.093 |
| Prior concussion(s) | 1.34 | (.87, 2.08) | 0.185 | CSD | 1.36 | (1.05, 1.75) | 0.019 |
| MVT vs. fall | 0.56 | (.34, .93) | 0.024 | SR2 | 1.90 | (1.25, 2.88) | 0.003 |
| Injury Group | 0.003a,b,c | GNG | 1.00 | (0.75, 1.34) | 0.993 | ||
| mTBI LOC- vs. LOC+ | 2.56 | (1.32, 4.90) | 0.005 | DANA (n = 141) | |||
| mTBI LOC- vs. control | 1.96 | (1.24, 3.10) | 0.004 | SRT | 1.78 | (1.36, 2.34) | <0.001c |
| mTBI LOC+ vs. control | 0.77 | (0.40, 1.47) | 0.427 | CDS | 1.27 | (1.00, 1.60) | 0.048 |
| Worker's Compensation | 0.96 | (0.52, 1.77) | 0.896 | PRO | 1.43 | (1.10 1.86) | 0.008 |
| Loss of consciousnessd | 0.37 | (0.19, 0.72) | 0.003 | SP | 1.30 | (1.04, 1.62) | 0.023 |
| Posttraumatic amnesiad | 0.48 | (0.20, 1.12) | 0.091 | GNG | 1.36 | (1.04, 1.79) | 0.027 |
| Retrograde amnesiaa | 1.53 | (0.61, 3.86) | 0.367 | CDD | 1.09 | (0.86, 1.38) | 0.457 |
| Head CT ordereda | 0.62 | (0.35, 1.10) | 0.099 | M2S | 1.00 | (0.80, 1.24) | 0.974 |
| Medication after injury | MS | 1.16 | (0.92, 1.45) | 0.217 | |||
| Opioid | 0.50 | (0.28, 0.88) | 0.016 | SR2 | 1.56 | (1.20, 2.03) | 0.001 |
| Non-opioid | 0.77 | (0.46, 1.27) | 0.305 | ImPACT (n = 100) | |||
| Self-reported symptoms | Verbal memory | 1.37 | (0.98, 1.93) | 0.067 | |||
| SCAT3 symptom severity | 0.69 | (0.52, 0.91) | 0.008 | Visual memory | 1.40 | (1.04, 1.87) | 0.024 |
| BSI-18 somatization | 0.68 | (0.53, 0.87) | 0.002b,c | Visual motor speed | 1.22 | (0.90, 1.66) | 0.197 |
| BSI-18 depression | 0.88 | (0.70, 1.10) | 0.248 | Reaction time | 0.90 | (0.67, 1.21) | 0.484 |
| BSI-18 anxiety | 0.82 | (0.65, 1.03) | 0.084 | ||||
| BSI-18 global severity | 0.76 | (0.60, 0.97) | 0.024 | ||||
| SWLS total | 1.02 | (0.84, 1.25) | 0.835 | ||||
| PCL-C total | 0.88 | (0.69, 1.11) | 0.265 | ||||
Predictor in the demographics multivariate model. bPredictors in the demographic+symptoms multivariate model. cPredictors in the best-fitting demographic+symptoms+performance multivariate model. dRecorded for mTBI group only.
Bold indicates p < .01.
An alternate model with similar fit was found when swapping DANA SRT with ANAM SR2. WTAR, symptom, and performance measures were standardized to facilitate comparisons of hazard ratios (HR). ADHD, attention-deficit/hyperactivity disorder; ANAM, Automated Neuropsychological Assessment Metrics; BSI-18, 18-item Brief Symptom Inventory; CDD, code substitution-delayed; CDS, code substitution learning; CSD, code substation delayed; DANA, Defense Automated Neurobehavioral Assessment; Govt., government; GNG, go/no-go; ImPACT, Immediate Postconcussion Assessment and Cognitive Testing; LOC, loss of consciousness; M2S, matching to sample; mBESS, Modified Balance Error Scoring System; MS, memory search; mTBI, mild traumatic brain injury; MTH, mathematical processing; MVT, motor vehicle-traffic accident; PCL-C, Post-traumatic Stress Disorder (PTSD) Checklist – Civilian; PRO, procedural reaction time; PRT, procedural reaction time; SAC, Standardized Assessment of Concussion; SCAT3, Sport Concussion Assessment Tool Symptom Checklist; SES, Hollingshead socioeconomic status score; SP, spatial processing; SRT, simple reaction time; SR2, simple reaction time 2; SWLS, Satisfaction with Life Scale. WTAR, Wechsler Test of Adult Reading; ANAM and DANA scores are all throughput scores except for Go/no-go d-prime.