Clinical Validation of Canadian WAIS-III Index Short Forms in Inpatient Neuropsychiatry and Forensic Psychiatry

Recent research has provided some support for the concurrent validity of two-subtest short forms for estimating Canadian WAIS-III Index scores in the standardization sample (Lange & Iverson, in press). The purpose of this study was to examine the efficacy of using various two-subtest short forms to estimate Canadian WAIS-III Index scores in a clinical population. Participants were 100 inpatients from two large psychiatric hospitals in British Columbia, Canada. Using all possible two-subtest combinations, estimated VCI, POI, and WMI scores were generated by prorating subtest scaled scores and using the Canadian normative data (Wechsler, 2001). The agreement rate between full form and short form index scores was very high for all subtest combinations (range = 90-98%). Two-subtest short forms were useful for estimating VCI, POI, and WMI scores in this population.

WAIS-R factor structure in Alzheimer's disease patients: a comparison of alternative models and an assessment of their generalizability

The WAIS-R is often used in neuropsychological evaluations of individuals with probable Alzheimer's disease (AD), but its factor structure in this population is unknown. Moreover, theories and past research findings make competing predictions concerning its structure. Using confirmatory factor analysis, the authors compared 5 alternative WAIS-R factor models among 516 AD patients: 1-factor (Spearman's g) and 2-factor (Verbal IQ and Performance IQ) models; a 3-factor model including Verbal Comprehension (VC), Perceptual Organization (PO), and Freedom From Distractibility (FD) factors; a 3-factor model in which Digit Symbol loads on PO rather than FD; and a 3-factor model in which Digit Symbol loads on both PO and FD. Results favored the 3-factor model in which Digit Symbol loads on PO rather than FD. Moreover, this model fit the data best among subsamples of patients defined by age, dementia severity, years of education, and gender.

Development and preliminary validation of a Satz-Mogel short form of the WAIS-III in a sample of persons with substance abuse disorders

We developed a Satz-Mogel short form of the WAIS-III and evaluated its accuracy for predicting IQs of 50 men with substance abuse disorders. Means for age, education, and Full Scale IQ were 44.20 years (SD = 7.23), 12.82years (SD = 1.53), and 98.06 (SD = 11.93). Correlations between the forms were significant for the 11 subtests (all rs> or =.79) and three IQs (all rs> or =.93). Short form estimated Verbal, Performance, and Full scale IQs were within +/-6 points of the WAIS-III 92% 80% and 90% of the time. The abbreviation may be used to estimate general intelligence, but interpretation of short-form-based IQ discrepancies should be avoided. The short form detected reliable WAIS-III Verbal-Performance IQ discrepancies only 67% of the time.

Test-retest reliability of the WAIS-R Satz-Mogel short form in a normal elderly sample

Test-retest reliability of the WAIS-R Satz-Mogel short form was tested on a sample of 122 normal elderly volunteer subjects with mean age of 70.4. Subjects' performance was assessed over 3 annual probes. Reliability coefficients for sums of scaled scores on Verbal subscale and Full Scale ranged between 0.79 and 0.83. Corresponding coefficients for Performance subscale ranged between 0.70 and 0.72. The percentage of subjects who showed change between two probes of more than 1 SD was the highest for the Performance subscale. Implications for clinical use, particularly for the purpose of estimation of premorbid intellectual functioning are discussed.

Head injury and the Satz-Mogel type short form WAIS-R

The current study investigated the efficacy of a Satz-Mogel type short form of the WAIS-R in a closed head injury (CHI) population and whether the short form's effectiveness varied by lesion site. Data were taken from the files of 79 CHI patients, 20 with left hemisphere damage, 15 with right hemisphere damage, 29 with bilateral damage, and 15 with only diffuse damage. Information about IQ scores and age-corrected subtest scores was examined. As expected, correlations between two forms, for both IQ scores and subtest scores were high. However, there was a remarkable percentage of deviation in scaled score points and changes in intellectual classification for some of these scores. No evidence was found to support the notion that usefulness of the short form varied according to the location of lesion.