TEST-RETEST PRACTICE EFFECTS AND TEST SCORE CHANGES OF THE WAIS-R IN RECOVERING TRAUMATICALLY BRAIN-INJURED SURVIVORS

A group of adult TBI subjects who were tested at approximately 2, 4, 8, and 12 months postinjury with the WAIS-R were compared with a matched control group of similar adult TBI survivors who were tested twice with the WAIS-R at approximately 2 and 12 months postinjury. No significant differences were noted between the two groups on numerous preinjury, injury, or postinjury variables. Both groups demonstrated significant gains in both IQ and subtest scaled scores at 1 year postinjury. Significantly greater change scores were demonstrated in the experimental group than in the control group, suggesting possible test-retest practice effects in Performance IQ and several subtests. Trend analyses detected both linear and quadratic recovery curves, with recovery slowing by the third evaluation. Implications of results for clinical practice are discussed.