Participant satisfaction with dementia prevention research: Results from Home-Based Assessment trial

The Associations of Phosphorylated Tau 181 and Tau 231 Levels in Plasma and Cerebrospinal Fluid with Cognitive Function in Alzheimer's Disease: A Systematic Review and Meta-Analysis

Background

Cerebrospinal fluid (CSF) or blood biomarkers like phosphorylated tau proteins (p-tau) are used to detect Alzheimer's disease (AD) early. Increasing studies on cognitive function and blood or CSF p-tau levels are controversial.

Objective

Our study examined the potential of p-tau as a biomarker of cognitive status in normal control (NC), mild cognitive impairment (MCI), and AD patients.

Methods

We searched PubMed, Cochrane, Embase, and Web of Science for relevant material through 12 January 2023. 5,017 participants from 20 studies-1,033 AD, 2,077 MCI, and 1,907 NC-were evaluated. Quantitative analysis provided continuous outcomes as SMDs with 95% CIs. Begg tested publication bias.

Results

MCI patients had lower CSF p-tau181 levels than AD patients (SMD =-0.60, 95% CI (-0.85, -0.36)) but higher than healthy controls (SMD = 0.67). AD/MCI patients had greater plasma p-tau181 levels than healthy people (SMD =-0.73, 95% CI (-1.04, -0.43)). MCI patients had significantly lower p-tau231 levels than AD patients in plasma and CSF (SMD =-0.90, 95% CI (-0.82, -0.45)). MCI patients showed greater CSF and plasma p-tau231 than healthy controls (SMD = 1.34, 95% CI (0.89, 1.79) and 0.43, (0.23, 0.64)). Plasma p-tau181/231 levels also distinguished the three categories. MCI patients had higher levels than healthy people, while AD patients had higher levels than MCI patients.

Conclusions

CSF p-tau181 and p-tau231 biomarkers distinguished AD, MCI, and healthy populations. Plasma-based p-tau181 and p-tau231 biomarkers for AD and MCI need further study.

An innovative approach to recruiting participants for dementia research: primary care and researcher perspectives

Aim: To describe clinician and researcher perceptions of a new, patient preference focused approach to recruiting patients for research from primary care-based memory clinics. Methods: Memory clinic clinicians completed a survey and key informants completed an individual interview to gather their perceptions of this new program. Results: The majority of clinicians were 'satisfied' or 'very satisfied' with this recruitment approach and indicated that this approach would have minimal negative impact on patient care or create conflict of interest. Key informants valued the program for its patient-centred approach, the integration of research into care and potential for increased recruitment. Discussion: These findings are suggestive of support for this recruitment approach. Pilot testing will inform feasibility, effectiveness and process improvements.

Associations between Participant Characteristics and Participant Feedback about an Unsupervised Online Cognitive Assessment in a Research Registry

BACKGROUND

This study aims to understand whether and how participant characteristics (age, gender, education, ethnocultural identity) are related to their feedback about taking a remote, unsupervised, online cognitive assessment.

METHODS

The Brain Health Registry is a public online registry which includes cognitive assessments. Multivariable ordinal regressions assessed associations between participant characteristics and feedback responses of older (55+) participants (N=11,553) regarding their Cogstate Brief Battery assessment experience.

RESULTS

Higher age, secondary education or less, Latino identity, and female gender were associated with a poorer assessment experience; higher age and a non-White identity were associated with experiencing the assessment instructions as less clear; and higher age, non-White identity, and secondary education or less were associated with rating additional human support with the assessment as more useful.

DISCUSSION

Our findings highlight the importance of improving the design and instructions of unsupervised, remote, online cognitive assessments to better suit the needs of diverse communities.

Feasibility and Acceptability of a Dietary Intervention to Reduce Salt Intake and Increase High-Nitrate Vegetable Consumption in Malaysian Middle-Aged and Older Adults with Elevated Blood Pressure: Findings from the DePEC-Nutrition Trial

The DePEC-Nutrition trial is a complex dietary and behavioural intervention of salt intake reduction combined with increased high-nitrate vegetable consumption among Malaysian middle-aged and older adults with elevated blood pressure. This study aimed to assess the feasibility and acceptability of the trial. Participants were recruited from the South East Asia Community Observatory (SEACO) database and randomised into one of four groups: (1) low salt; (2) high-nitrate vegetable; (3) combined high-nitrate vegetable and low salt; and (4) control. The intervention included a combination of group counselling sessions, information booklets, reinforcement videos and text messages to modify dietary behaviour. The primary outcomes evaluated were the measures of feasibility and acceptability of (1) recruitment, follow-up attendance and retention; (2) data collection procedures and clinical outcome measures; and (3) individual and combined multi-modal dietary interventions. A total of 74 participants were recruited, and the 10-month retention rate was 73%. Data collection procedures were acceptable with minimal missing data. All intervention strategies were feasible and acceptable, with group counselling being the most acceptable strategy. This study provides important insights into improving the screening process of participants, facilitating their access to the research facilities and refining the measurement protocols and dietary recommendations, which are instrumental in formulating the design of a full-scale definitive DePEC-Nutrition trial.

Impact of potential modifications to Alzheimer's disease clinical trials in response to disruption by COVID-19: a simulation study

BACKGROUND

The COVID-19 pandemic disrupted Alzheimer disease randomized clinical trials (RCTs), forcing investigators to make changes in the conduct of such trials while endeavoring to maintain their validity. Changing ongoing RCTs carries risks for biases and threats to validity. To understand the impact of exigent modifications due to COVID-19, we examined several scenarios in symptomatic and disease modification trials that could be made.

METHODS

We identified both symptomatic and disease modification Alzheimer disease RCTs as exemplars of those that would be affected by the pandemic and considered the types of changes that sponsors could make to each. We modeled three scenarios for each of the types of trials using existing datasets, adjusting enrollment, follow-ups, and dropouts to examine the potential effects COVID-19-related changes. Simulations were performed that accounted for completion and dropout patterns using linear mixed effects models, modeling time as continuous and categorical. The statistical power of the scenarios was determined.

RESULTS

Truncating both symptomatic and disease modification trials led to underpowered trials. By contrast, adapting the trials by extending the treatment period, temporarily stopping treatment, delaying outcomes assessments, and performing remote assessment allowed for increased statistical power nearly to the level originally planned.

DISCUSSION

These analyses support the idea that disrupted trials under common scenarios are better continued and extended even in the face of dropouts, treatment disruptions, missing outcomes, and other exigencies and that adaptations can be made that maintain the trials' validity. We suggest some adaptive methods to do this noting that some changes become under-powered to detect the original effect sizes and expected outcomes. These analyses provide insight to better plan trials that are resilient to unexpected changes to the medical, social, and political milieu.

Lived time and the affordances of clinical research participation

In this article, we address the problem of participation and the dominant focus on motivations in clinical research. We explore participation as a relational mode of 'being in time' in Alzheimer's dementia prevention-a field profoundly shaped by changing bodies through time, as well as promissory trends towards future-oriented preventative medicine. Analysis of interviews with older adults in a clinical trial platform demonstrates that what research 'does' or might (not) 'do' for participants emerges as temporalities of participants' everyday lives become entangled with the possibilities, constraints and demands of biomedical 'research time'. As well as consistent desires to help (future) others, we identify incidental possibilities for care that emerged from continued research participation. We argue that longitudinal research participation can productively be understood as a set of evolving affordances: whereby differing limits and possibilities for care and agency emerge in a world where dementia cannot be cured. Future trial participation is considered in terms of 'therapeutic affordances', which are likely to fluctuate as certain lived or imagined futures unfold. As such, we open up a conceptual space to think about why, how, and critically, when participation happens, as it emerges in relation to lived times of ageing and everyday life.

Using Digital Tools to Advance Alzheimer's Drug Trials During a Pandemic: The EU/US CTAD Task Force

The 2020 COVID-19 pandemic has disrupted Alzheimer’s disease (AD) clinical studies worldwide. Digital technologies may help minimize disruptions by enabling remote assessment of subtle cognitive and functional changes over the course of the disease. The EU/US Clinical Trials in Alzheimer’s Disease (CTAD) Task Force met virtually in November 2020 to explore the opportunities and challenges associated with the use of digital technologies in AD clinical research. While recognizing the potential of digital tools to accelerate clinical trials, improve the engagement of diverse populations, capture clinically meaningful data, and lower costs, questions remain regarding the stability, validity, generalizability, and reproducibility of digital data. Substantial concerns also exist regarding regulatory acceptance and privacy. Nonetheless, the Task Force supported further exploration of digital technologies through collaboration and data sharing, noting the need for standardization of digital readouts. They also concluded that while it may be premature to employ remote assessments for trials of novel experimental medications, remote studies of non-invasive, multi-domain approaches may be feasible at this time.

Adapting Alzheimer Disease and Related Dementias Clinical Research Evaluations in the Age of COVID-19

In March 2020, the novel coronavirus (COVID-19) became a global pandemic that would cause most in-person visits for clinical studies to be put on pause. Coupled with protective stay at home guidelines, clinical research at the Icahn School of Medicine at Mount Sinai Alzheimer's Disease Research Center (ISMMS ADRC) needed to quickly adapt to remain operational and maintain our cohort of research participants. Data collected by the ISMMS ADRC as well as from other National Institute on Aging (NIA) Alzheimer Disease centers, follows the guidance of the National Alzheimer Coordinating Center (NACC). However, at the start of this pandemic, NACC had no alternative data collection mechanisms that could accommodate these safety guidelines. To stay in touch with our cohort and to ensure continued data collection under different stages of quarantine, the ISMMS ADRC redeployed their work force to continue their observational study via telehealth assessment. On the basis of this experience and that of other centers, NACC was able to create a data collection process to accommodate remote assessment in mid-August. Here we review our experience in filling the gap during this period of isolation and describe the adaptations for clinical research, which informed the national dialog for conducting dementia research in the age of COVID-19 and beyond.

Ethical Considerations in Communicating Alzheimer's Disease Neuroimaging Biomarker Test Results to Symptomatic Individuals

This article examines ethical issues associated with the return of AD neuroimaging results to cognitively symptomatic individuals. Following a review of research on patient and study partner reactions to learning the results of biomarker testing for AD, we examine ethical issues that will be of increasing significance as the field transitions to an era wherein disease-modifying treatments for AD become available. We first review the ethical justification for returning AD biomarker results to individuals who desire them. We then address a more novel question: whether, and to what extent, clinicians or clinical researchers should influence the decisions of individuals who are potentially reluctant to learn their AD imaging results. We argue that in many cases, it is ethically correct to explore, and sometimes alter, factors that may be inhibiting one's desire to know these test results. Our argument is grounded in the premise that having more complete information about changes that may be happening in one's brain will generally yield more informed participation in decisions about one's own care, thereby promoting autonomy. Finally, on the assumption that we have established that it is frequently ethically correct to try to communicate testing information, we examine considerations regarding (not whether but) how this is best accomplished, discussing the concept of responsible transparency. We suggest that both (1) explorations of why one may or may not want to learn results of AD biomarker imaging and (2) the responsible return of such test results is best accomplished using a transactional model of communication.

Older adults' motivations to participate or not in epidemiological research. Qualitative inquiry on a study into dementia in Switzerland

INTRODUCTION

High participation in epidemiological studies is crucial for both external and internal validity. Because response rates have declined in recent years, there is an increasing need to understand the drivers and the barriers to research participation. This study aims to uncover the motivations in favour and against participation of older adults to an epidemiological study on health and dementia.

METHODS

Twenty-two older adults, who already took part to the preliminary phase of an epidemiological study in Switzerland, agreed to participate to semi-structured, face-to- face interviews. An experienced researcher carried out all interviews in a quiet place of choice of the interviewee either at their domicile or the university, between November 2019 and January 2020. The interviews were audio and video taped, transcribed verbatim, and thematically analysed by two independent researchers.

RESULTS

We identified three main themes for the motivations in favour of participation (i.e. personal, related to the outcomes of research, and altruistic motivations), and we highlighted subthemes for each theme (e.g. personal motivations: curiosity; civic engagement; interest in the topic; trust in science; everyone counts; openness; play the game). Motivations against participation reflected the first two themes, while there was no counterpart for altruistic motivations.

CONCLUSIONS

Our thematic analysis revealed that older adults hold specular motivations in favour and against participation to research. Studying jointly motivations in favour and against provides information for recruitment strategies and to overcome barriers to participation, respectively. Participatory action research can inform the design and conduction of and should precede epidemiological studies in older adults, and can potentially contribute to attain high response rates.