Practice effects, test-retest stability, and dual baseline assessments with the California Verbal Learning Test in an HIV sample

Repeated neuropsychological assessments have been recently employed to inve stigate the natural course and effects of interventions in individuals with human immunodeficiency virus (HIV) infection. Important considerations whe n interpreting serial assessments are the roles of practice effects and tes t-retest reliability on follow-up performance. Although several statistical and methodological controls have been proposed for minimizing practice eff ects, they have not been empirically tested in HIV samples. Three groups (H IV+/symptomatic, HIV+/asymptomatic, HIV- "at risk" controls) were administe red the California Verbal Learning Test (CVLT) twice with a brief test-rete st interval. Significant practice effects were observed on six of the CVLT measures. Test-retest stability coefficients were reported. A third and fou rth administration of the CVLT was conducted to observe the impact of the d ual baseline assessment approach on test performance. Trend analyses indica ted that the dual baseline approach is a viable method for minimizing pract ice effects. The dual baseline approach also lead to improvement in a numbe r of the stability coefficients. Limitations and future directions are disc ussed. (C) 2001 National Academy of Neuropsychology. Published by Elsevier Science Ltd.