An Online, Person-Centered, Risk Factor Management Program to Prevent Cognitive Decline: Protocol for A Prospective Behavior-Modification Blinded Endpoint Randomized Controlled Trial

Adherence and intensity in multimodal lifestyle-based interventions for cognitive decline prevention: state-of-the-art and future directions

Preventing dementia and Alzheimer's disease (AD) is a global priority. Multimodal interventions targeting several risk factors and disease mechanisms simultaneously are currently being tested worldwide under the World-Wide FINGERS (WW-FINGERS) network of clinical trials. Adherence to these interventions is crucial for their success, yet there is significant heterogeneity in adherence reporting across studies, hindering the understanding of adherence barriers and facilitators. This article is a narrative review of available evidence from multimodal dementia prevention trials. A literature search was conducted using medical databases (MEDLINE via PubMed and SCOPUS) to select relevant studies: nonpharmacological multimodal interventions (i.e., combining three or more intervention domains), targeting individuals without dementia, and using changes in cognitive performance and/or incident mild cognitive impairment or dementia as primary outcomes. Based on the findings, we propose future adherence reporting to encompass both participation (average attendance to each intervention component) and lifestyle change using dementia risk scores (e.g., the LIBRA index). Moreover, we provide an estimation of the expected intensity of multimodal interventions, defined as the ratio of the expected dose (i.e., the overall amount of the intervention offered specified in the trial protocol) to duration (in months). Adjusting the expected dose by average adherence enables estimation of the observed dose and intensity, which could be informative for identifying optimal dosage thresholds that maximize cognitive benefits across different populations. Finally, this article provides an overview of the determinants of adherence to multimodal interventions, emphasizing the need for improved adherence reporting to inform the design and implementation of precision prevention interventions.

Equity of access in rural and metropolitan dementia diagnosis, management, and care experiences: an exploratory qualitative study

BACKGROUND

The limited allocation of resources to rural and regional communities is a major contributor to healthcare inequities in Australia. Distribution of health service resources between metropolitan and rural communities commonly sees highly populated areas prioritised over more sparsely populated and geographically vast areas. As such, challenges impacting dementia diagnosis, management, and care in metropolitan areas are experienced more acutely in rural areas. This study aimed to examine equity of access to dementia diagnosis, management, and care services amongst people who experienced the process of dementia diagnosis as a patient or significant other (partner/spouse, adult children, siblings, and friends) throughout rural and metropolitan Australia.

METHODS

This exploratory qualitative study consisted of thirty-three online semi-structured interviews with thirty-seven people with experience of the dementia diagnosis process as a patient and/or significant other. Interviews explored symptoms of dementia, health professionals consulted, tests conducted, and challenges faced throughout the diagnosis and post-diagnosis process. Rurality was defined by the Australian Statistical Geography Standard Remoteness Areas (ASGS-RA) and the Modified Monash Model (MMM). Thematic analysis was conducted, with Russell's (2013) Dimensions of Access framework (geography, affordability, availability, acceptability, accommodation, awareness, and timeliness) guiding data analysis.

RESULTS

Participants were distributed across various regions of Australia: seven interviews from inner regional Australia, five interviews from outer regional Australia, and twenty-one interviews from metropolitan areas. Disparities in access between metropolitan and rural areas emerged in five key dimensions: 1) geography impeding ability to access services; 2) affordability of travel expenses; 3) availability of healthcare and support services; 4) acceptability of available health professionals and services; and 5) awareness of local services and resources. The dimensions of accommodation and timeliness of care were experienced as challenges irrespective of location, with lengthy appointment wait times and difficulty navigating complex systems. However, rurality often compounded the challenges in dementia diagnosis, management, and care.

CONCLUSIONS

Significant health inequities persist between rural and metropolitan communities that must be prioritised in endeavours to promote equitable dementia diagnosis, management, and care. Targeted action to address disparities is vital to mitigate the impact of rurality, particularly as clinical practice evolves with research advancements.

Factors influencing rates of unsupervised assessment of short-term learning in cognitively unimpaired adults

BACKGROUND

In older adults with preclinical Alzheimer's disease (AD), learning curves derived from validated psychological learning paradigms are reduced to an extent greater than impairment, or decline, on neuropsychological memory tests.

OBJECTIVE

This study aimed to examine how age, sex, education, mood, and general dementia risk, which also increases risk for preclinical AD, could influence learning curves.

METHODS

1050 adults enrolled in the BetterBrains trial completed 10 blocks of ORCA-LLT learning trials over 5 days. Learning curves were derived from improvement in accuracy over trials. Participants also completed questionnaires of demography and mood, and the CAIDE risk score was computed for each participant.

RESULTS

Most participants (67%) completed ≥6 blocks of ORCA-LLT. Older age (d = 0.75), lower education (d = 0.50), and higher dementia risk (d = 0.36) were associated significantly with slower learning rates.

CONCLUSIONS

In older adults, learning curves are influenced subtly by age, education, and dementia risk but not by sex or mood.

Associations between multidomain modifiable dementia risk factors with AD biomarkers and cognition in middle-aged and older adults

This study aimed to determine associations between modifiable dementia risk factors (MDRF), across domains mood symptomatology, lifestyle behaviors, cardiovascular conditions, cognitive/social engagement, sleep disorders/symptomatology, with cognition, beta-amyloid (Aβ) and tau, and brain volume. Middle-aged/older adults (n=82) enrolled in a sub-study of the Healthy Brain Project completed self-report questionnaires and a neuropsychological battery. Cerebrospinal fluid levels of Aβ 1-42, total tau (t-tau), and phosphorylated tau (p-tau181) (Roche Elecsys), and MRI markers of hippocampal volume and total brain volume were obtained. Participants were classified as no/single domain risk (≤1 domains) or multidomain risk (≥2 domains). Compared to the no/single domain risk group, the multidomain risk group performed worse on the Preclinical Alzheimer's Cognitive Composite (d=0.63, p=.005), and Executive Function (d=0.50, p=.016), and had increased p-tau181 (d=0.47, p=.042) and t-tau (d=0.54, p=.021). In middle-aged/older adults, multidomain MDRFs were related to increases in tau and worse cognition, but not Aβ or brain volume. Findings suggest that increases in AD biomarkers are apparent in midlife, particularly for individuals with greater burden, or variety of MDRFs.

A Mediterranean Diet and Walking Intervention to Reduce Cognitive Decline and Dementia Risk in Independently Living Older Australians: The MedWalk Randomized Controlled Trial Experimental Protocol, Including COVID-19 Related Modifications and Baseline Characteristics

BACKGROUND

Several clinical trials have examined diet and physical activity lifestyle changes as mitigation strategies for risk factors linked to cognitive decline and dementias such as Alzheimer's disease. However, the ability to modify these behaviors longer term, to impact cognitive health has remained elusive.

OBJECTIVE

The MedWalk trial's primary aim is to investigate whether longer-term adherence to a Mediterranean-style diet and regular walking, delivered through motivational interviewing and cognitive-behavioral therapy (MI-CBT), can reduce age-associated cognitive decline and other dementia risk factors in older, independently living individuals without cognitive impairment.

METHODS

MedWalk, a one-year cluster-randomized controlled trial across two Australian states, recruited 60-90-year-old people from independent living retirement villages and the wider community. Participants were assigned to either the MedWalk intervention or a control group (maintaining their usual diet and physical activity). The primary outcome is 12-month change in visual memory and learning assessed from errors on the Paired Associates Learning Task of the Cambridge Neuropsychological Test Automated Battery. Secondary outcomes include cognition, mood, cardiovascular function, biomarkers related to nutrient status and cognitive decline, MI-CBT effectiveness, Mediterranean diet adherence, physical activity, quality of life, cost-effectiveness, and health economic evaluation.Progress and Discussion:Although COVID-19 impacts over two years necessitated a reduced timeline and sample size, MedWalk retains sufficient power to address its aims and hypotheses. Baseline testing has been completed with 157 participants, who will be followed over 12 months. If successful, MedWalk will inform interventions that could substantially reduce dementia incidence and ameliorate cognitive decline in the community.

TRIAL REGISTRATION

Registered on the Australia New Zealand Clinical Trials Registry ANZCTR 12620000978965 (https://www.anzctr.org.au).

Protocol for a Mixed-Methods Process Evaluation of BetterBrains: A Person-Centered Online Intervention to Delay Cognitive Decline in Adults at Risk of Dementia

BACKGROUND

The BetterBrains Randomized Controlled Trial (RCT) will evaluate the effectiveness of an online, person-centered, risk factor management, coaching intervention in community-dwelling, healthy adults at risk of cognitive decline. Multi-component interventions are challenging to evaluate due to program complexity and personalization to individual needs and contexts. This paper describes a multi-level process evaluation conducted alongside the BetterBrains RCT.

OBJECTIVE

To understand how and why the BetterBrains intervention was effective or ineffective at reducing cognitive decline in healthy adults whilst considering the context in which it was implemented.

METHODS

1,510 non cognitively-deteriorated community-dwelling adults aged 40-70 years old at risk of cognitive decline will be recruited and randomly assigned to the intervention or control group. All BetterBrains intervention participants, coaches, and the research team will be included in the evaluation. A mixed-methods design will be used, guided by The Framework for Implementation Fidelity and the program logic model. Data will be sourced from interviews, focus groups, surveys, BetterBrains coach notes, participant weekly check-in surveys, and audio recordings of intervention coaching sessions. Quantitative data will be analyzed via descriptive and inferential statistics and qualitative data will be analyzed using content and thematic analysis.

RESULTS

The process evaluation will provide information about contextual and influencing factors related to the implementation of BetterBrains and the RCT outcomes.

CONCLUSION

Understanding how BetterBrains was implemented and its associated impacts will inform the translation of the program into community and clinical settings, providing easy access to online, personalized dementia prevention services.

Validation of a digit symbol substitution test for use in supervised and unsupervised assessment in mild Alzheimer's disease

INTRODUCTION

The Digit-Symbol-Substitution Test (DSST) is used widely in neuropsychological investigations of Alzheimer's Disease (AD). A computerized version of this paradigm, the DSST-Meds, utilizes medicine-date pairings and has been developed for administration in both supervised and unsupervised environments. This study determined the utility and validity of the DSST-Meds for measuring cognitive dysfunction in early AD.

METHOD

Performance on the DSST-Meds was compared to performance on the WAIS Coding test, and a computerized digit symbol coding test (DSST-Symbols). The first study compared supervised performance on the three DSSTs versions in cognitively unimpaired (CU) adults (n = 104). The second compared supervised DSST performance between CU (n = 60) and mild-symptomatic AD (mild-AD, n = 79) groups. The third study compared performance on the DSST-Meds between unsupervised (n= 621) and supervised settings.

RESULTS

In Study 1, DSST-Meds accuracy showed high correlations with the DSST-Symbols accuracy (r = 0.81) and WAIS-Coding accuracy (r = 0.68). In Study 2, when compared to CU adults, the mild-AD group showed lower accuracy on all three DSSTs (Cohen's d ranging between 1.39 and 2.56) and DSST-Meds accuracy was correlated moderately with Mini-Mental State Examination scores (r = 0.44, p < .001). Study 3 observed no difference in DSST-meds accuracy between supervised and unsupervised administrations.

CONCLUSION

The DSST-Meds showed good construct and criterion validity when used in both supervised and unsupervised contexts and provided a strong foundation to investigate the utility of the DSST in groups with low familiarity to neuropsychological assessment.