Short-form prediction of WAIS-R scores in a sample of individuals diagnosed with multiple sclerosis.

A short form of the Wechsler Adult Intelligence Scale--Revised (WAIS-R) developed by Ward (WAIS-R/7 SF; 1990) was used to generate Verbal, Performance, and Full Scale IQ scores (VIQ, PIQ, and FSIQ, respectively) in 66 individuals diagnosed with multiple sclerosis (MS). Short-form scores were highly correlated with WAIS-R scores. However, the short-form VIQ and PIQ, but not FSIQ, scores differed significantly from corresponding WAIS-R scores. WAIS-R/7 SF VIQ, PIQ, and FSIQ scores fell within 5, 9, and 6 absolute error points, respectively, of corresponding WAIS-R IQ scores in 95% of cases. Classification of IQ scores into ranges (e.g., average, high average, etc.) based on the scheme outlined by Wechsler (1981) was consistent between WAIS-R/7 SF and WAIS-R scores in 81.8% (for VIQ), 74.8% (for PIQ), and 89.4% (for FSIQ) of cases. These findings are discussed within the context of using the WAIS-R/7 SF in the assessment of MS patients.