Lillian Hassan Thomas, “Cancer-Related Cognitive Change Test Scores May Be Influenced by Practice Effects”
Mentor: Adam Greenberg, MCW (partnership with UWM)
Poster #5
As the cancer survival rate continues to increase, a larger number of patients are experiencing Cancer-Related Cognitive Change (CRCC) – a variation in cognitive performance associated with cancer treatment. Characterizing markers of CRCC has been a persistent problem that must be solved in order to determine the underlying mechanisms involved and, ultimately, devise auxiliary treatments to mitigate these effects. We recently conducted a preliminary longitudinal CRCC study during which a battery of neuropsychological tests was administered to 33 cancer patients at both pre- and post-chemotherapy timepoints. Results indicated an unexpected trend: many patients self-reported a decline in cognition after receiving chemotherapy, but their neuropsychological test scores improved across this same period. The aim of our current research is to determine whether practice effects, a known shortcoming of repeated neuropsychological testing, may be masking the cognitive impairment experienced (and subjectively reported) by cancer patients. To achieve this aim, we corrected for any practice effect using a Standard Regression-Based Change model (SRB) and calculated Reliable Change Indices (RCI) to determine how many patients displayed meaningful score changes between timepoints. We found that prior to correcting for practice effects, approximately 15% of our sample displayed a reliable score change, indicating a significant improvement after chemotherapy treatment. However, after correcting for practice effects, the proportion of patients displaying reliable score change decreased to approximately 9%. This decrease in the number of patients exhibiting a reliable change indicates that some amount of the score improvement observed was the result of a practice effect, rather than true cognitive improvement. Currently, we are administering the same neuropsychological test battery to a sample of healthy controls (n=11; ongoing) to further explore the score change in repeat neuropsychological testing and further characterize the suspected practice effects.