Cross-validation of the alternative impairment index

The Alternative Impairment Index, a new composite measure of neuropsychological deficit, was cross-validated by comparison with an established measure of neuropsychological impairment, the Halstead Impairment Index. An initial study gave agreement of 60% (15/25) between the Halstead Impairment Index and the Alternative Impairment Index. Analysis of a cross-validation sample of 50 brain-damaged patients with complete Halstead-Reitan Neuropsychological Test scores yielded agreement of 66% (33/50) on severity for the Alternative Impairment Index and Halstead Impairment Index.