TABLE 1.

Description of the Traumatic Brain Injury Clinical Trials network core outcome measures

Measure	Description	Designed to measure	Properties
GOS-E (Glasgow Outcome Scale Extended)17	Administered by structured interview with a focus on independence in the home and community as changed by traumatic brain injury (TBI). Results classify the outcome at 8 levels ranging from death to upper-good recovery	Global outcome; developed to improve sensitivity and reliability over the original GOS33	Relationship with initial severity and multiple measures of TBI outcome superior to original GOS. More sensitive to change from 3 to 6 mo than GOS34
COWAT (Controlled Oral Word Association Test)35	Subject generates as many words as possible beginning with a given letter within 1 min. Score is the total number of words generated over 3 trials	Verbal fluency under time pressure, thought to reflect frontal/executive function	Sensitive to effects of TBI25,34
Trail Making Test36	Two components, A and B, involve connecting items sequentially in a visual array. Part A requires simple number sequencing while part B requires alternation between numbers and letters. Scores are the times needed for completion	Sustained and divided attention; mental flexibility; psychomotor speed, set-shifting ability	Sensitive to TBI severity, to recovery over time and related to other measures of outcome.37,38 Correlated with functional outcomes such as need for supervision39 and functional safety40
California Verbal Learning Test23	Learning of a 16-word list over 5 trials. Scores include total number of words recalled, number within categories, recognition memory, etc	Verbal learning, use of category information to promote recall	Sensitive to the effects of TBI and its severity of injury27,34
Digit span (from WAIS III)41	Maximum span for repeating a series of digits forward and backward	Auditory working memory	Sensitive to severity of injury and recovery42
Processing speed index (from Wechsler Adult Intelligence Scale–III)41	Two components: Digit-symbol coding: Rapid transcription of symbols Symbol search: Rapid visual scanning of geometric forms	Visual processing speed; visuomotor speed	Has a component of working memory; sensitive to the effects of TBI35
Stroop Task22	Generates a conflict between automatic and effortful processing by requiring identification of color of ink ignoring printed words (eg, “red” written in green ink)	Executive abilities, particularly inhibition of automatic responses	Sensitive to effects of TBI even in those with good recovery39