Multivariate logistic regression analysis revealed that age, systolic blood pressure (SBP), pupil size, subarachnoid hemorrhage (SAH), SII, PLR, serum potassium concentration [K+], serum calcium concentration [Ca2+], international normalized ratio (INR), C-reactive protein (CRP) and co-systemic immune inflammation index combined with carbon dioxide (coSII-CO2) (P < 0.001) were independent prognostic factors for GOS in patients with severe TBI. This evidence concerns the gene CRP and subarachnoid hemorrhage.