Association of TIMP-3* and clinical outcomes after traumatic brain injury in univariate and full logistic regression models
| Independent variables in model | For each SD change in TIMP-3OR (95% CI)† | P values |
| ARDS | ||
| TIMP-3 | 1.5 (1.1 to 2.1) | 0.006 |
| TIMP-3, AIS Head score, age>60 years, male sex, crystalloid*, platelet*, pRBC*, plasma* transfusion, shock by arrival base deficit | 1.4 (1.0 to 2.0) | 0.036 |
| Sensitivity analysis: multivariate model‡ excluding subjects requiring massive transfusion§ | 1.5 (1.0 to 2.3) | 0.033 |
| Sensitivity analysis: multivariate model‡ excluding subjects who developed VAP before ARDS | 1.5 (1.0 to 2.2) | 0.036 |
| Death | ||
| TIMP-3 | 1.7 (1.2 to 2.3) | 0.002 |
| TIMP-3, AIS Head score, age>60 years, male sex, crystalloid*, platelet *, blood*, plasma* transfusion, shock by arrival base deficit§ | 1.9 (1.2 to 2.8) | 0.002 |
| Sensitivity analysis: multivariate model‡ excluding subjects requiring massive transfusion | 1.9 (1.2 to 3.1) | 0.005 |
Crystalloid infusion included as a continuous variable indicating liters transfused in the first 12 hours of admission.
* Plasma sample obtained on arrival to the ED.
†Regression model output for scaled predictor variable is interpreted as the change in the OR for outcome of interest for each SD (2090 pg/mL) increase in the plasma concentration of TIMP-3 on ED arrival, holding all other variables in the model constant. AIS, models exclude subjects with AIS Head score=6 (non-survivable injury). Platelet, pRBC, and plasma (fresh-frozen plasma) coded as binary variables indicating any transfusion of the specific products in the first 12 hours of admission. Crystalloid infusion included as a continuous variable indicating liters transfused in the first 12 hours of admission.
‡Multivariate model refers to full model with independent variables specified in the row above. Massive transfusion defined as requiring >10 units of pRBCs in 24 hours. Sensitivity analyses excluded 16 (9%) of 182 patients in the full cohort who required massive transfusion.
§Base deficit of <−4 on ED arrival arterial blood gas analysis.
AIS, Abbreviated Injury Scale; ARDS, acute respiratory distress syndrome; ED, emergency department; pRBCs, packed red blood cells; TIMP-3, tissue inhibitor of matrix metalloproteinase 3; VAP, ventilator-associated pneumonia.