Screening for visual-perceptual deficits following closed head injury: a short form of the Visual Form Discrimination...

The purpose of this study was to evaluate the concurrent validity and clinical utility of a short form of the Visual Form Discrimination Test in persons with closed head injuries (n = 62). Given the homogeneity of the items, and patients' apparent consistency in responding, we hypothesized that scores from an eight-item short form would be highly similar to the scores from the full version of the test (i.e. 16 items). The mean difference between the short form and full version was less than one point, and the correlation between the two forms was 0.86. Applying a clinical decision rule resulted in a 'normal/impaired' overall correct classification rate of 98.4%. The short form shows considerable promise as a brief test of visual discrimination in persons with closed head injuries.