Three-subtest short form of the Wechsler Adult Intelligence Scale-III for patients with psychotic disorders: A preliminary report

Abstract

Objective: To evaluate the usefulness or a 3-subtest short form of the wechsler Adult intelligence Scale-III for estimating full-scale intelligence quotient scores by comparing it with an established 4-subtest short form. Patients and Methods: Full-scale intelligence quotient scores were evaluated using the 4-subtest short form, which includes information, arithmetic, digit symbols, and block design, in a group of 49 patients with psychotic disorders and 49 healthy controls matched for age and educational status. Regression analysis was used to evaluate a model consisting of the 3 subtests, information, arithmetic, and digit symbols. Results: Variables included in the 3-subtest short form accounted for 94% of the variance for patients with psychotic disorder and 88% of the variance for healthy controls. Correlation coefficients were 0.97 for patients with psychotic disorders and 0.94 for healthy controls. Both for patients and healthy controls, the 3-subtest estimates fell within 5 points of the 4-subtest scores (with a maximum of 76 points) in 98% of cases. Conclusion: The data suggest that the proposed 3-subtest short form is almost as effective as the 4-subtest short form for providing an estimate of general intelligence of patients with psychotic disorders. © 2005 Hong Kong College of Psychiatrists.