Objective: To evaluate the validity of the General Ability Measure for Adults (GAMA) in a sample of patients with traumatic brain injury (TBI).
Design: Comparison with criterion standards of Wechsler Adult Intelligence Scale-Revised (WAIS-R) and measures of injury severity.
Setting: Regional rehabilitation center.
Participants: One-year prospective series of consecutive rehabilitation referrals, including 42 adult patients with TBI.
Main outcome measures: GAMA and WAIS-R IQ scores were obtained within 1 year after injury and compared with each other and with measures of injury severity.
Results: The GAMA demonstrated statistically significant covariance with the WAIS-R and was able to discriminate severe TBI from mild/moderate TBI. The correlation between the GAMA and length of coma fell just short of statistical significance.
Conclusions: The GAMA is sufficiently sensitive to the presence or absence of severe TBI but may not be sufficiently sensitive to the exact degree of injury severity.