Predictive value of an early Glasgow Outcome Scale score: 15-month score changes

Does an early Glasgow Outcome Scale (GOS) assessment provide a reliable indicator of later outcome in a patient with traumatic brain injury (TBI)? The authors examined the utility of the GOS during early treatment as a predictor of outcome score 15 months postinjury by analyzing outcome score change in a group of patients with closed head injuries.

Glasgow Outcome Scale scores assessed within 3 months of injury (baseline) were compared with scores obtained at 15 months postinjury in 121 patients, primarily young military personnel. Score changes between baseline and 8 months postinjury were also studied in a subgroup of 72 patients. The impact of initial injury severity (determined by the duration of unconsciousness) on score change was also explored. The GOS scores at three time points within the 15-month period-baseline (within 3 months of injury), 8, and 15 months postinjury-were examined to ascertain when the maximal GOS score had been reached.

Baseline GOS score was a reliable predictor of outcome in patients with an initial score of 5 (no disability) or 4 (mild disability), but not in patients with an initial score of 3 (severe disability). Patients who remained unconscious for more than 24 hours did not have significantly lower outcome scores than those who experienced loss of consciousness for less than 24 hours at 15 months postinjury. Interestingly, the duration of unconsciousness did not affect the likelihood of an improved score during the study period in patients with a GOS score of 3 or 4 at baseline. An updated evaluation conducted after the early phases of treatment is needed to provide a realistic prognosis of severe TBI.