Measuring neuropsychological change following breast cancer treatment: An analysis of statistical models

Abstract

This article considers the quantitative techniques currently in use in the evaluation of cognitive impairments associated with chemotherapy treatment for breast cancer. To illustrate differences among analytical approaches, all analyses were applied to baseline and posttreatment scores on neuropsychological tests obtained from Stages I and II breast cancer patients receiving either chemotherapy or hormonal therapy; a healthy control group with similar demographics to those of the treatment groups was also included. Conventional group analyses were compared with individual-based analyses (standardized regression-based and reliable change methods). Both univariate and multivariate techniques with and without covariates produced negligible effects. In contrast, results of the individual-based analyses identified a subset of participants in the chemotherapy group who experienced a severe decline in function on two or more tests. Differences between the control and treatment groups were greater than differences between the treatment groups alone. The standardized regression-based approach was more sensitive than the reliable change index in detecting chemotherapy and hormonal therapy subjects whose performance was different from baseline scores on two or more tests (roughly 80% vs. 50% of participants). From a clinical perspective, the degree of impairment determined on the basis of the individual-based methodologies could have a major impact on quality of life for those affected. On the whole, we argue that the standardized regression-based approach, allowing for the assessment of individual practice effects and evaluation of moderator variables, is the method of choice in this context.

Interventions for cognitive deficits in patients with a brain tumor: an update

“…Furthermore, although results at the group level (e.g., statistical comparisons of group means) are very informative in studies of treatment effectiveness, they may also mask the variability in individual responses to interventions [70].…”

Er cytostatika skadelig for hjernen?

“…Slike testmetoder er ikke problemfrie, saerlig ved måling av individuelle endringer over tid (6). De fleste av testene har også svak sammenheng med dagliglivets problemer (7).…”

Neuroprotective Effects of Vitamin D in Multiple Sclerosis

“…Numerous studies have offered evidence for chemotherapy-induced adverse neuropsychological sequelae, independent of the effects of depression or anxiety, in the domains of memory, mental flexibility, processing speed, attention, visuospatial ability, and motor function [48][49][50][51]. These impairments are clinically significant, with pervasive impact on functioning in the home, social, educational, and/or professional environments [52]. Although research on outcomes of vitamin supplementation on chemotherapy-induced cognitive dysfunction is scant, one important study indicates a positive role of vitamin D. In a study of women with early-stage breast cancer who were being treated with chemotherapy, Simone et al [53] report that 88% of the sample indicated improvement in cognitive abilities after completion of a 10-point plan that included a supplement regimen high in vitamin D. Although additional research would be needed to isolate the contribution of vitamin D alone, these results show therapeutic promise for vitamin D in the context of chemotherapy-induced cognitive dysfunction.…”