Practice effects and the use of alternate forms in serial neuropsychological testing

Abstract

Accurate understanding of practice characteristics, performance stability, and error on neuropsychological tests is essential to both valid clinical assessment and maximization of signal detection for clinical trials of cognitive enhancing drugs. We examined practice effects in 28 healthy adults. As part of a larger study using donepezil and simulating a Phase I trial, participants were randomized into: placebo, no-treatment and donepezil. Donepezil results are presented elsewhere. Neuropsychological tests were administered in a fixed order for 6 weeks, with alternate forms available for most tests. Despite alternate forms, ANOVAs revealed significant improvements for the pooled control group (placebo and no-treatment) on all tests except Letter Number Sequencing and Trails B. Learning occurred principally in the first three to four sessions. PASAT and Stroop interference showed the greatest learning. Thus, serial assessment with alternate forms may attenuate retest effects on some tests, but continued learning occurs on novel tests or those in which an advantageous test-taking strategy can be identified. Alternate forms and baseline practice sessions may help control early, rapid improvements in clinical trials.

Detecting the significance of changes in performance on the Stroop Color-Word Test, Rey's Verbal Learning Test, and the Letter Digit Substitution Test: The regression-based change approach

“…When performing serial testing to evaluate deterioration or improvement in cognitive functioning, it is of crucial importance to understand the relationship between earlier and later test administrations. Indeed, a serious problem in serial testing is that varying test results may occur even when there was no true change in the cognitive status of a person (Beglinger et al, 2005). This problem is mainly attributable to the less than perfect temporal stability of test scores and the occurrence of test-retest effects such as practice effects .…”

A Randomized, Placebo-Controlled, Crossover Trial of Cannabis Cigarettes in Neuropathic Pain

“…Alternate forms (A-F) were used to minimize practice effects. 6,8 A list of 12 words (4 words from each of 3 semantic categories) were presented, and the subject was asked to recall as many words as possible in any order. After a 20-minute delay, the subject was asked to recall the words once again (ie, delayed recall).…”

“…39 This can be somewhat ameliorated by the use of alternate forms 8 and, since the largest practice effects typically occur between the first and second testing, 21 preexposure to the measures (ie, dual baselines) are recommended. 6,69 For this study, we used 6 separate versions of the Hopkins Verbal Learning Test, and incorporated a practice testing session at the time of the screening interview to lessen early practice effects. Despite our attempts to limit practice effects (using alternate forms, conducting a prebaseline practice session), these effects cannot be completely eliminated when subjects are tested repeatedly over a brief period.…”

Short-term practice effects in amnestic mild cognitive impairment: implications for diagnosis and treatment

“…First, such data could inform the design and interpretation of drug trials for this prodromal phase of dementia (Beglinger et al, 2005a). For example, it is necessary to know whether some degree of practice effects are expected in amnestic MCI participants before initiation of a drug.…”