SCREENING FOR VISUAL-PERCEPTUAL DEFICITS FOLLOWING CLOSED-HEAD INJURY- A SHORT-FORM OF THE VISUAL FORM DISCRIMINATION TEST

The purpose of this study was to evaluate the concurrent validity and clinical utility of a shea 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 hyp othesized that scores from an eight-item short form would be highly si milar to the scores derived from the full version of the test (i.e. 16 items). The mean difference between the shea form and full version wa s 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 co nsiderable promise as a brief test of visual discrimination in persons with closed head injuries.