Test-retest reliability of the Halstead Impairment Index in hospitalized alcholic and nonalcoholic males with mild to moderate neuropsychological impairment.

Seven measures of neuropsychological functioning, the resulting Impairment Index described by Halstead, and Trails A and B were administered to drug-free alcoholic inpatients (n=91) within 7 days of their last drink and again 17 days later. Nonalcoholic medical inpatients (n=20) with similar education, age, and socioeconomic characteristics were also given these tests twice, with 2 to 3 weeks separating the test administrations. Both groups showed levels of mild to moderate impairment on the first testing and were judged to have stable brain functioning between the first and second testing. Significant Pearson's coefficients of correlation between test-retest scores indicated similar psychometric reliabilities in both groups. In contrast, the reliability of the tests was judged to be questionable when Halstead's binary classification of "normal" versus "abnormal" was used to classify individual patients. Consequently, and consistent with clinical experience, we urge caution in interpreting these clinical neuropsychological tests when they are administered repeatedly within a 2- to 3-week period to a single individual with stabilized brain functioning.