Concurrent validity of a WAIS—R seven-subtest short form in patients with brain impairment.

The concurrent validity of a Wechsler Adult Intelligence Scale-Revised (WAIS-R) seven-subtest short form was examined in 138 patients with closed-head injuries and 49 patients with presumed dementia. In patients with closed-head injuries, the average short form IQ score was within 1 point of the actual Verbal, Performance, and Full Scale IQ (VIQ, PIQ, and FSIQ) scores. The validity coefficients for these patients ranged from.90 to.95. In patients with presumed dementia, the short form underestimated the average VIQ by nearly 5 points and the average FSIQ by 3.5 points. However, the validity coefficients for these patients were uniformly high (.91 to to.95 ). Examination of the frequency distributions revealed that there was a percentage of patients whose short form IQs and actual IQs were highly discrepant. Research designed to determine the variables that reduce the accuracy of the short form in clinical populations is needed.