BACKGROUND: In @entity2033 ( @entity2033 ), cognitive changes due to disease-progression or treatment are potentially confounded by "practice effects" ( @entity24882 ) - performance improvement from prior exposure to test materials. OBJECTIVE: A practice run-in ("dual baseline") was used in an @entity2033 cognitive trial to determine if @entity24882 could be minimized and evaluate performance trajectories over multiple visits. METHODS: Non-depressed adults (N=36) with mild to moderate @entity2033 -related @entity73 participated in a clinical trial to examine the efficacy of @entity837 to enhance cognition. Cognitive tests were administered at three visits (2 weeks separating each visit), before active treatment randomization. Some tests were also administered at screening. Therefore 3-4 pre-treatment repetitions were available. We examined test improvement using repeated-measures ANOVAs with planned pairwise comparisons. RESULTS: Despite the practice run-in and use of alternate test forms, results indicated ongoing improvements over at least three test sessions on all three UHDRS cognitive tests. Trails A and B showed improvements between the third and fourth session, which suggests that one pre-baseline visit may not be effective in reducing practice on this important and commonly used test. CONCLUSIONS: Overall, 7 out of 13 variables showed some degree of short-term @entity24882 , even after multiple sessions and alternate forms. Tests assessing processing speed and memory may be particularly confounded by ongoing @entity24882 across at least 2-3 sessions. Practice run-in periods and alternate forms may help minimize the impact of such effects in @entity2033 clinical trials but awareness of which tests are most susceptible to @entity24882 is important in clinical trial design.

Practice Effects and Stability of Neuropsychological and UHDRS Tests Over Short Retest Intervals in XXXX .

@entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive deficits'] @entity837 :: ('MESH:D015283', 'Chemical') :: ['citalopram'] @entity24882 :: ('MESH:D065606', 'Disease') :: ['PE'] @entity2033 :: ('MESH:D006816', 'Disease') :: ['Huntington disease', 'HD']
@entity2033 :: (MESH:D006816,Disease) :: ['Huntington Disease']
