Short-term practice effects in mild cognitive impairment: Evaluating different methods of change

Abstract

Practice effects are improvements on cognitive tests as a result of repeated exposure to testing material. However, variability exists in the literature about whether patients with amnestic mild cognitive impairment (MCI) display practice effects, which may be partially due to the methods used to calculate these changes on repeated tests. The purpose of the current study was to examine multiple methods of assessing short-term practice effects in 58 older adults with MCI. The cognitive battery, which included tests of memory (Hopkins Verbal Learning Test–Revised and Brief Visuospatial Memory Test–Revised) and processing speed (Symbol Digit Modalities Test and Trail Making Test Parts A and B), was administered twice across one week. Dependent t tests showed statistically significant improvement on memory scores (ps < .01, ds = 0.8–1.3), but not on processing speed scores. Despite this, the sample showed no clinically meaningful improvement on any cognitive scores using three different reliable change indices. Regression-based change scores did identify relatively large groups of participants who showed smaller than expected practice effects, which may indicate that this method is more sensitive in identifying individuals who may portend a declining trajectory. Practice effects remain a complex construct, worthy of continued investigation in diverse clinical conditions.

Objective features of subjective cognitive decline in a United States national database

“…Consistent with prior findings [39], psychomotor speed measures were not vulnerable to practice effects. Rather, in this domain, the older adults showed annual decline over the period of follow-up, which was significantly greater in those with SCD compared to those without SCD.…”

The interactive Physical and Cognitive Exercise System (iPACES&trade;): effects of a 3-month in-home pilot clinical trial for mild cognitive impairment and caregivers

“…Cognitive and biomarker assessments were repeated at the beginning and end of each single bout training session and thus before and after 2-week familiarization windows (game-only and iPACES). These additional assessments were included primarily to washout learning/practice effects 63 , 64 ahead of the major mid-point and final (3M) assessments which were of central, a priori, interest. Single bout and 2-week familiarization results were examined for exploratory and feasibility purposes and reported elsewhere (unpublished thesis by VanBrakle, 2016).…”

Using practice effects for targeted trials or sub-group analysis in Alzheimer’s disease: How practice effects predict change over time

“…Third, from a pragmatic perspective of conducting a clinical trial, we employed the most straightforward method to define the practice effects by using the first two assessments. Although other methods such as the complex standardized regression-based method can be used [34], these methods involve the use of demographic variables and may cause selection bias. Finally, the practice effects can be altered by different cognitive domains, demographic variables, subject variables, retest interval, etc., our analyses did not address these issues.…”