De Wit, Liselotte

AbstractBackgroundEvidence suggests that select hippocampal subfields are implicated in the initial stages of Alzheimer’s disease (AD) and are selectively involved in objective memory. Less is known whether subfields are associated with informant-reported memory difficulties of individuals with a diagnosis of mild cognitive impairment (MCI).MethodData from 56 participants with a diagnosis of amnestic MCI were included in the present study. To test whether FreeSurfer derived hippocampal subfields (CA1–4, subiculum, presubiculum, and dentate gyrus) were associated with objective (learning and delayed recall) and informant-reports of memory difficulties, we used multiple linear regression analysis. Subfields were adjusted for total intracranial volume, and age, sex, and years of education were included as covariates in all models.ResultsLarger presubiculum, subiculum, and CA4/dentate gyrus volumes were associated with higher delayed recall scores, and larger subiculum and CA4/dentate gyrus volumes were associated with fewer informant-reports of memory difficulties. There were no statistically significant associations between subfields and learning scores.DiscussionFindings from the present study support the idea that difficulties with memory-dependent everyday tasks in older adults with MCI may signal a neurodegenerative process while increasing understanding of subfields correlates of these memory-specific functional difficulties. Continued investigations into identifying patterns of subfield atrophy in AD may aid early identification of those at higher risk of dementia conversion while advancing precision medicine.

Background: In Alzheimer’s disease and related disorders (ADRD) research, common outcome measures include cognitive and functional impairment, as well as persons with mild cognitive impairment (pwMCI) and care partner self-reported mood and quality of life. Studies commonly analyze these measures separately, which potentially leads to issues of multiple comparisons and/or multicollinearity among measures while ignoring the latent constructs they may be measuring. Objective: This study sought to examine the latent factor structure of a battery of 12-13 measures of domains mentioned above, used in a multicomponent behavioral intervention (The HABIT® program) for pwMCI and their partners. Methods: Exploratory factor analysis (EFA) involved 214 pwMCI-partner pairs. Subsequent Confirmatory factor analyses (CFA) used 730 pairs in both pre- and post-intervention conditions. Results: EFA generated a three-factor model. Factors could be characterized as partner adjustment (29.9%), pwMCI adjustment (18.1%), and pwMCI impairment (12.8%). The subsequent CFA confirmed our findings, and the goodness-of-fit for this model was adequate in both the pre- (CFI = 0.937; RMSEA = 0.057, p = 0.089) and post-intervention (CFI = 0.942; RMSEA = 0.051, p = 0.430) groups. Conclusion: Results demonstrated a stable factor structure across cohorts and intervention conditions suggesting that three broad factors may provide a straightforward and meaningful model to assess intervention outcome, at least during the MCI phase of ADRD.

ObjectivesWe adapted a self‐efficacy measure for managing chronic illness to be specific to persons with mild cognitive impairment (pwMCI). The aim of this study was to investigate the psychometric properties of the scale, the self‐efficacy for managing MCI scale, for use in research.MethodsAnalyses involved data from pwMCI enrolled in a behavioral intervention study that completed the measure five times from intervention enrollment to 18‐month post‐intervention. Factor structure, construct validity, internal consistency, and test‐retest reliability were analyzed.ResultsFactor analysis identified two factors, related to self‐efficacy for daily activities and managing MCI, which corresponded with domains from the original chronic illness self‐efficacy scale. Consistent with prior research, construct validity analysis suggested an association between memory‐loss self‐efficacy and psychosocial distress, but not cognitive or functional ability. Further analyses supported the scale's internal and test‐retest reliability.ConclusionsCurrently, no “gold standard” scale of memory‐loss self‐efficacy for pwMCI exists, despite the positive impact self‐efficacy may have on modifiable health behaviors. Overall, results supported the notion that the scale is a valid and reliable measure of memory‐loss self‐efficacy for pwMCI.

Background: Research has shown that individuals with mild cognitive impairment (MCI) value quality of life (QoL) above and beyond cognitive function or other potential outcomes in MCI. There is evidence supporting the negative impact of poor physical function on QoL ratings. Objective: The study explored whether a modified measure of self-efficacy for managing MCI and education mediated and/or moderated the relationship between physical function and QoL in persons with MCI. Methods: Baseline data from 200 participants with MCI were obtained from a larger study assessing the effectiveness of a behavioral intervention. Physical function was assessed by the Short Physical Performance Battery. QoL was assessed with the Quality of Life in Alzheimer’s Disease scale. Memory-related self-efficacy was assessed using a modified 9-item version of the Chronic Disease Self-Efficacy Scales. Mediation and moderation analyses tested the hypotheses that self-efficacy and education alter the association between physical function and QoL in individuals with MCI. All analyses were adjusted for age, cognitive severity, and sex. Results: Self-efficacy for managing MCI was a significant mediator of the association between physical function and perceived QoL. Individuals with better physical function reported higher self-efficacy which was associated with higher QoL ratings. Conclusions: Greater self-efficacy for managing MCI mediated the negative association between physical function and quality of life in this exploratory study. Interventions aimed at enhancing memory self-efficacy in MCI may improve perceived QoL, even in the presence of poor physical function. Future research is needed to investigate this further.