Development and cross-validation of a short form impairment index

The Brain Age Quotient (BAQ) is an actuarial combination of four HalsteadReitan neuropsychology test battery scores (Category errors. Tactual Performance Test— Total Time, Tactual Performance Test—Location Score and Trails-B Score) and two performance subtests for the Wechsler Adult Intelligence Scale (Block Design and Digit Symbol). The present studies investigated the value of a short form of the BAQ, the Short Form Impairment Index (SFII), composed of the Trails-B Score and two subtests of the Wechsler and also twice cross-validated the short form. Statistical analysis yielded a Pearson r = .90, for both the initial study and each of the cross-validations. Further research and clinical considerations are discussed.