Table 3. Multivariable regression examining factors predictive of VPTs among TBI participants controlling for demographics (Models 1–3) and multivariable ordinal regression examining factors predictive of magnitude of response expressed as ‘mild’, ‘moderate’ or ‘strong’ response to FL or GL as compared with PL tints among TBI participants while controlling for demographics (Models 4–5).
| Variable | Model 1: PL VPT | Model 2: FL VPT | Model 3: GL VPT | Model 4: FL VPT magnitude of response | Model 5: GL VPT magnitude of response |
|---|---|---|---|---|---|
| PHQ-9 | – | β=−0.048 (p=0.02*) | β=−0.051 (p=0.02*) | OR=0.833, 95% CI 0.717 to 0.969 (p=0.02*) | OR=0.829, 95% CI 0.689 to 0.998 (p=0.047*) |
| PCS-EN | β=−0.027 (p=0.01*) | – | – | – | – |
| SF-12v2 | |||||
| PCS | – | – | – | – | OR=1.201, 95% CI 1.029 to 1.403 (p=0.021*) |
| MCS | – | – | – | – | OR=1.166, 95% CI 1.031 to 1.318 (p=0.02*) |
| BTACT Z-scores | |||||
| Word list recall | – | – | – | – | – |
| Digits span backward | – | – | – | – | – |
| Number series | – | β=0.349 (p=0.01*) | β=0.376 (p=0.009*) | – | – |
| Category fluency | – | – | – | – | OR=0.138, 95% CI 0.023 to 0.836 (p=0.03*) |
| Backward counting | – | – | – | – | – |
| TBI severity code | – | – | – | – | – |
SF-12v2, a health survey measuring physical and mental health whose domains contribute to PCS and MCS scores.
The symbol ‘–’ denotes predictors that are not significant.
Significance (p<0.05) denoted by *.
BTACT, Brief Test of Adult Cognition by Telephone; FL, FL-41 lens; GL, grey-filtering lens; MCS, Mental Component Summary; PCS, Physical Component Summary; PCS-EN, Pain Catastrophizing Scale; PHQ-9, Patient Health Questionnaire-9; PL, plano lens; SF-12v2, Short-Form 12-Item Survey-version 2; TBI, traumatic brain injury; VPT, visual photosensitivity threshold.