Prognosis and Outcome Prediction
Background and objective:
Previous studies have shown a correlation between initial GCS and outcome after sTBI. This correlation has been used to prognosticate outcome assessed as GOS. The aim was to investigate the value of GCS in prognostication of outcome in sTBI.
Methods and materials:
Patients with sTBI admitted 2002-2005. Inclusion criteria: GCS at intubation and sedation ≤ 8, age 15-70yr, first recorded CPP ≥ 10mmHg, and arrival within 24 h. Exclusion criteria: pregnant/lactating woman, penetrating injury. Protocol guided treatment based on the Lund concept was used. Independent staff evaluated the GOS at 3 and 6 months. Contingency analysis was used for evaluation of overall effects and ROC curve analysis was employed to evaluate the value of GCS in the prognostication of the dicotomized GOS (unfavourable GOS 1-3 and favourable GOS 4-5) outcome at 3 and 6 months.
In all, 48 patients, mean age 35.5yr, were included, no patient were lost to follow-up. Median GCS at intubation and sedation was 6 (3-8). Contingency analysis revealed no overall effects between the initial GCS and GOS at 3 months (P = 0.533) and 6 months (P = 0.269). Using the 3 months dicotomized GOS and the GCS value with highest accuracy (GCS ≤ 4) ROC analysis showed a sensitivity of 52.2% and specificity of 80.0%. The positive predictive value was 70.6% and negative prognostic value 64.5%. Positive likelihood ratio was 2.61 and negative likelihood ratio 0.60. Similar results were found using the 6 months outcome. If mortality prognostication is the ultimate goal the corresponding values are 30.4%, 84%, 63.6%, 56.8%, 1.90% and 0.83%, respectively.
In patients treated with an ICP targeted therapy, the prognostic value of initial GCS is insufficient to securely prognosticate the outcome. Based on our findings no absolute treatment decisions can be based on this variable.