Community Participation Transition After Stroke (COMPASS) Randomized Controlled Trial: Effect on Adverse Health Events.

OBJECTIVE: To compare adverse health events in intervention versus control group participants in the Community Participation Transition After Stroke trial to reduce barriers to independent living for community-dwelling stroke survivors. DESIGN: Randomized controlled trial. SETTING: Inpatient rehabilitation (IR) to home and community transition. PARTICIPANTS: Stroke survivors aged ≥50 years being discharged from IR who had been independent in activities of daily living prestroke (N=183). INTERVENTIONS: Participants randomized to intervention group (n=85) received home modifications and self-management training from an occupational therapist over 4 visits in the home. Participants randomized to control group (n=98) received the same number of visits consisting of stroke education. MAIN OUTCOME MEASURES: Death, skilled nursing facility (SNF) admission, 30-day rehospitalization, and fall rates after discharge from IR. RESULTS: Time-to-event analysis revealed that the intervention reduced SNF admission (cumulative survival, 87.8%; 95% confidence interval [CI], 78.6%-96.6%) and death (cumulative survival, 100%) compared with the control group (SNF cumulative survival, 78.9%; 95% CI, 70.4%-87.4%; P=.039; death cumulative survival, 87.3%; 95% CI, 79.9%-94.7%; P=.001). Thirty-day rehospitalization also appeared to be lower among intervention participants (cumulative survival, 95.1%; 95% CI, 90.5%-99.8%) than among control participants (cumulative survival, 86.3%; 95% CI, 79.4%-93.2%; P=.050) but was not statistically significant. Fall rates did not significantly differ between the intervention group (5.6 falls per 1000 participant-days; 95% CI, 4.7-6.5) and the control group (7.2 falls per 1000 participant-days; 95% CI, 6.2-8.3; incidence rate ratio, 0.78; 95% CI, 0.46-1.33; P=.361). CONCLUSIONS: A home-based occupational therapist-led intervention that helps stroke survivors transition to home by reducing barriers in the home and improving self-management could decrease the risk of mortality and SNF admission after discharge from rehabilitation.

Psychometric Evaluation of the Perceived Research Burden Assessment (PeRBA) in Longitudinal Studies of Alzheimer Disease Using Rasch Analysis.

INTRODUCTION: The Perceived Research Burden Assessment (PeRBA) was developed to measure participant perceptions of burden in research studies. This study aimed to examine the psychometric properties of this assessment using Rasch analysis in participants in the longitudinal studies of the Alzheimer disease (AD) and their family members. METHODS: PeRBA was administered to 443 participants in studies of AD and 212 family members across 4 Alzheimer Disease Research Centers. We used Rasch analysis to examine PeRBA's psychometric properties, and data-model fit both at item and scale levels. RESULTS: PeRBA demonstrated good reliability and item and person fit for participants and family members. A few items did not fit the model for participants or family members. Areas of content redundancy were found in items assessing similar amounts of perceived research burden. Areas of content gaps were also found, with no items assessing certain levels of perceived research burden. CONCLUSION: Analysis results support the good overall psychometric properties of PeRBA among research participants in studies of AD and their family members. Recommendations have been provided to improve the assessment, including rewording items and adding items that could account for a broader range of perceived research burden.

Evaluation of race as a predictor of fear of falling in Black older adults.

OBJECTIVE: Determine whether race predicts fear of falling (FOF) in older adults with a history of previous fall(s) while controlling for mobility performance, activity of daily living (ADL) independence, age, gender, and education. METHODS: We examined predictors of FOF among community-dwelling older adults using data from two longitudinal randomized controlled trials that implemented fall prevention programs for community-dwelling older adults. RESULTS: Two hundred fifty-nine participants were included in the analysis; 145 reported low FOF, while 59 reported high FOF. After controlling for mobility performance, ADL independence, and sociodemographic factors, Black older adults were more likely to report FOF (OR = 2.17) compared to White older adults. Overall, older adults with lower mobility performance/functioning scores were more likely to have FOF (OR = 0.08). CONCLUSIONS: Older adults (aged ≥65 years) who are at higher risk, based on a prior history of fall(s), are more susceptible to developing FOF, as evidenced by the older adults within this study, due to limited mobility performance and functioning. CLINICAL IMPLICATIONS: Black older adults may be at greater risk of FOF than their White counterparts based on previous fall history and level of functional mobility. Incorporating measures of objective performance-based function along with measures of psychological factors are viable methods to identify and address FOF within Black older adult populations.

Perceptions of Research Burden and Retention Among Participants in ADRC Cohorts.

OBJECTIVES: Alzheimer disease (AD) and related dementias clinical research is associated with significant participant burden. The Perceived Research Burden Assessment (PeRBA) measures participants' perceptions of logistical, psychological, and physical burdens. The purpose of this study was to assess PeRBA's psychometric properties, perceptual sources, and behavioral consequences with participants in a multisite study of participant retention in longitudinal cohort studies of Alzheimer disease and related dementias. DESIGN: Multicenter mixed methods. SETTING: In-person or phone. PARTICIPANTS: A total of 443 participants at 4 NIA-funded Alzheimer Disease Research Centers (ADRCs) were randomly selected and invited to participate if they were 45 years of age or more, enrolled in longitudinal studies, and had a Clinical Dementia Rating Scale global score ≤1. MEASUREMENTS: Participants completed a 20-minute survey including the 21-item PeRBA about their research participation. RESULTS: PeRBA demonstrated high-internal consistency and convergent validity. PeRBA scores correlated with expected perceptual factors. Higher PeRBA scores were associated with lower attendance and higher dropout rates. CONCLUSIONS: PeRBA can be used by researchers to identify participants who may feel overburdened and tailor approaches and strategies to support participants in longitudinal AD studies, maximizing participation, and reducing dropout. Making efforts to increase participants' understanding of study procedures, and building and maintaining trust throughout the study, can contribute to reducing perceived burden and potentially increasing retention in longitudinal AD studies.

Primary Care of Adult Patients After Stroke: A Scientific Statement From the American Heart Association/American Stroke Association.

Primary care teams provide the majority of poststroke care. When optimally configured, these teams provide patient-centered care to prevent recurrent stroke, maximize function, prevent late complications, and optimize quality of life. Patient-centered primary care after stroke begins with establishing the foundation for poststroke management while engaging caregivers and family members in support of the patient. Screening for complications (eg, depression, cognitive impairment, and fall risk) and unmet needs is both a short-term and long-term component of poststroke care. Patients with ongoing functional impairments may benefit from referral to appropriate services. Ongoing care consists of managing risk factors such as high blood pressure, atrial fibrillation, diabetes, carotid stenosis, and dyslipidemia. Recommendations to reduce risk of recurrent stroke also include lifestyle modifications such as healthy diet and exercise. At the system level, primary care practices can use quality improvement strategies and available resources to enhance the delivery of evidence-based care and optimize outcomes.

Effect of electroencephalogram-guided anaesthesia administration on 1-yr mortality: follow-up of a randomised clinical trial.

BACKGROUND: Intraoperative EEG suppression duration has been associated with postoperative delirium and mortality. In a clinical trial testing anaesthesia titration to avoid EEG suppression, the intervention did not decrease the incidence of postoperative delirium, but was associated with reduced 30-day mortality. The present study evaluated whether the EEG-guided anaesthesia intervention was also associated with reduced 1-yr mortality. METHODS: This manuscript reports 1 yr follow-up of subjects from a single-centre RCT, including a post hoc secondary outcome (1-yr mortality) in addition to pre-specified secondary outcomes. The trial included subjects aged 60 yr or older undergoing surgery with general anaesthesia between January 2015 and May 2018. Patients were randomised to receive EEG-guided anaesthesia or usual care. The previously reported primary outcome was postoperative delirium. The outcome of the current study was all-cause 1-yr mortality. RESULTS: Of the 1232 subjects enrolled, 614 subjects were randomised to EEG-guided anaesthesia and 618 subjects to usual care. One-year mortality was 57/591 (9.6%) in the guided group and 62/601 (10.3%) in the usual-care group. No significant difference in mortality was observed (adjusted absolute risk difference, -0.7%; 99.5% confidence interval, -5.8% to 4.3%; P=0.68). CONCLUSIONS: An EEG-guided anaesthesia intervention aiming to decrease duration of EEG suppression during surgery did not significantly decrease 1-yr mortality. These findings, in the context of other studies, do not provide supportive evidence for EEG-guided anaesthesia to prevent intermediate term postoperative death. CLINICAL TRIAL REGISTRATION: NCT02241655.

When I'm 64: Effects of an interdisciplinary gerontology course on first-year undergraduates' perceptions of aging.

One challenge for gerontology is getting more students interested in aging at an earlier point in their academic career. This study evaluated the impact of an interdisciplinary course on aging designed for first-year undergraduate students. The course aimed to expand students' appreciation of the personal and professional relevance of aging issues, with the goal of expanding their aging-related curricular and career interests. Main outcome variables of the study included knowledge of older adults and aging, attitudes toward older adults, and anxiety about personal aging. Participants included an intervention group enrolled in the course and a control group not enrolled in the course. Compared to baseline, at the end of the semester students in the class had more knowledge about aging and more positive explicit attitudes toward older adults, but their implicit attitudes toward older adults and anxiety about aging did not change. Control students showed no changes. These findings suggest that objective knowledge of aging and explicit attitudes improve with curricular intervention, but implicit attitudes and anxiety might be more difficult to change. Gerontology education is a complex undertaking whose diverse goals must be clearly articulated in order to guide curricular interventions and incite curiosity among young undergraduate students.

Preoperative Falls and Their Association with Functional Dependence and Quality of Life.

BACKGROUND: No study has rigorously explored the characteristics of surgical patients with recent preoperative falls. Our objective was to describe the essential features of preoperative falls and determine whether they are associated with preoperative functional dependence and poor quality of life. METHODS: This was an observational study involving 15,060 surveys from adult patients undergoing elective surgery. The surveys were collected between January 2014 and August 2015, with a response rate of 92%. RESULTS: In the 6 months before surgery, 26% (99% CI, 25 to 27%) of patients fell at least once, and 12% (99% CI, 11 to 13%) fell at least twice. The proportion of patients who fell was highest among patients presenting for neurosurgery (41%; 99% CI, 36 to 45%). At least one fall-related injury occurred in 58% (99% CI, 56 to 60%) of those who fell. Falls were common in all age groups, but surprisingly, they did not increase monotonically with age. Middle-aged patients (45 to 64 yr) had the highest proportion of fallers (28%), recurrent fallers (13%), and severe fall-related injuries (27%) compared to younger (18 to 44 yr) and older (65+ yr) patients (P < 0.001 for each). A fall within 6 months was independently associated with preoperative functional dependence (odds ratio, 1.94; 99% CI, 1.68 to 2.24) and poor physical quality of life (odds ratio, 2.18; 99% CI, 1.88 to 2.52). CONCLUSIONS: Preoperative falls might be common and are possibly often injurious in the presurgical population, across all ages. A history of falls could enhance the assessment of preoperative functional dependence and quality of life.

Tailored Calendar Journals to Ascertain Falls Among Older Adults.

Although falls are a serious health risk for community-dwelling older adults, their ascertainment has been complicated by issues such as recall and reporting biases. We examined a novel method, individualized tailored calendars, to accurately ascertain falls in older adults. A convenience sample of 125 cognitively normal participants enrolled in longitudinal studies of healthy aging at the Knight Alzheimer's Disease Ressearch Center was followed prospectively for 12 months. Tailored calendar journal pages were used to document falls daily and returned by mail monthly. Participants received a US$5 gift card incentive for each month returned. Participants returned 1,487 of 1,500 calendar months over the 12-month follow-up for 99.1% compliance rate. There were 154 falls reported. Tailored calendar journals and incentives may be effective in ascertaining falls among community-dwelling older adults. This tool could improve the accuracy of outcome measures for occupational therapy interventions.

Clinical Reasoning Guideline for Home Modification Interventions.

OBJECTIVE: The objective of this study was to develop and validate a clinical reasoning tool to describe an occupational therapist's clinical reasoning process while delivering home modification interventions. METHOD: We used a two-phase, mixed-methods approach. In Phase 1, we developed a personal factors guideline to support clinical reasoning in home modification interventions based on in-depth interviews, a focus group, and field observations of 6 home modification experts. In Phase 2, the guideline was validated by a second group of 6 home modification experts. RESULTS: During analysis, 16 personal and environmental factors with a corresponding set of conditions and strategies for each factor emerged to form a clinical reasoning guideline, which was validated by a second group of experts. CONCLUSION: Unpacking the "black box" of the clinical reasoning process has yielded a useful clinical reasoning tool that will allow occupational therapists to deliver complex interventions with fidelity.

Consistency of participation over time among persons aging with physical disability as measured by a tool designed for use among community-based organizations.

BACKGROUND: Community participation measures for persons aging with disability were developed and evaluated to support community-based organizations (CBOs) with efficient assessment of change in participation and need for supports/services to facilitate participation. OBJECTIVE: To evaluate a set of nine activity domain measures to broadly assess community participation and change in participation over time. METHODS: A community-based sample (N = 323) of persons ages 45-65 responded to a survey with repeated measures three times annually (T1, T2, T3) between 2019 and 2022. Nine activity domain measures were developed based on extant research and evaluated with assistance from community-based support service providers. Statistical analyses employed T-tests and chi-square tests to assess change in participation over time, perceptions of participation satisfaction, and assistance needed to facilitate participation. Participants were asked if they thought changes were attributable to aging, the COVID-19 pandemic, or other factors. RESULTS: Findings showed varying levels of participation across the nine activity domains, with the lowest participation rate for employment and the highest participation rates for personal leisure and managing medications across T1, T2, and T3. Change in participation over the three-year period was limited; most change was reported as activity reduction. In general, respondents indicated that reduction was due to their aging or the COVID-19 pandemic. Personal assistance, transportation, environmental modifications, and improved health were identified as factors needed to help increase participation levels. CONCLUSION: The activity domain measures demonstrated efficiency in identifying participation rates and change. CBOs may deem them useful for assessing support and service needs to facilitate participation.

Falls and Alzheimer Disease.

Falls are the leading cause of injury, disability, and injury-related mortality in the older adult population. Older adults with Alzheimer disease (AD) are over twice as likely to experience a fall compared to cognitively normal older adults. Intrinsic and extrinsic fall risk factors may influence falls during symptomatic AD; intrinsic factors include changes in cognition and impaired functional mobility, and extrinsic factors include polypharmacy and environmental fall hazards. Despite many known fall risk factors, the high prevalence of falls, and the presence of effective fall prevention interventions for older adults without cognitive impairment, effective fall prevention interventions for older adults with AD to date are limited and inconclusive. Falls may precede AD-related cognitive impairment during the preclinical phase of AD, though a narrow understanding of fall risk factors and fall prevention interventions for older adults with preclinical AD limits clinical treatment of falls among cognitively normal older adults with preclinical AD. This mini review explores fall risk factors in symptomatic AD, evidence for effective fall prevention interventions in symptomatic AD, and preclinical AD as an avenue for future falls research, including recommendations for future research directions to improve our understanding of falls and fall risk during preclinical AD. Early detection and tailored interventions to address these functional changes are needed to reduce the risk of falls for those at risk for developing AD. Concerted efforts should be dedicated to understanding falls to inform precision fall prevention strategies for this population.

Differences in Daily Activity Performance Between Inpatient Rehabilitation Facility and Home Among Stroke Survivors.

BACKGROUND: Stroke survivors are one of the largest consumer groups of rehabilitation services. Despite improvement in daily activities while in inpatient rehabilitation, many have difficulty performing daily activities at home after discharge. The difference in performance between a standard clinical context and at home is poorly understood. OBJECTIVE: To better understand differences in activity performance during transition from inpatient rehabilitation facility (IRF) to home, we examined daily activity performance scores from 2 different environments (IRF and home) at the same time point (discharge). METHODS: This was a cross-sectional analysis using baseline data from a randomized controlled trial. Participants were stroke survivors aged ≥50 who planned to discharge home from the IRF. The Functional Independence Measure and Section GG codes (both converted to International Classification of Functioning, Disability, and Health scores) were conducted per protocol first at home and then in the IRF at discharge (≤3 days apart, order not randomized). RESULTS: Among 57 participants, activity scores at home were significantly worse than scores at IRF discharge. Over 40% of participants had discharge scores indicating no-to-mild impairment for shower/tub transfer, walking, and going up/down stairs, while home visit scores indicated moderate-to-complete impairment for those activities. The greatest differences in scores were for shower/tub transfer (median difference 1.5, 95% CI 1.00-2.00) and going up/down stairs (median difference 1.50, 95% CI 1.00-2.00). CONCLUSION: The environment plays an important role in stroke survivors' functioning at home. Future studies should further examine how the environment impacts activity performance upon returning home following stroke.

Removing home hazards for older adults living in affordable housing: A stepped-wedge cluster-randomized trial.

BACKGROUND: Falls are the leading cause of injury, disability, premature institutionalization, and injury-related mortality among older adults. Home hazard removal can effectively reduce falls in this population but is not implemented as standard practice. This study translated an evidence-based home hazard removal program (HARP) for delivery in low-income senior apartments to test whether the intervention would work in the "real world." METHODS: From May 1, 2019 to December 31, 2020, a stepped-wedge cluster-randomized trial was used to implement the evidence-based HARP among residents with high fall risk in 11 low-income senior apartment buildings. Five clusters of buildings were randomly assigned an intervention allocation sequence. Three-level negative-binomial models (repeated measures nested within individuals, individuals nested within buildings) were used to compare fall rates between treatment and control conditions (excluding a crossover period), controlling for demographic characteristics, fall risk, and time period. RESULTS: Among 656 residents, 548 agreed to screening, 435 were eligible (high fall risk), and 291 agreed to participate and received HARP. Participants were, on average, 72 years, 67% female, and 76% Black. Approximately 95.4% of fall prevention strategies and modifications implemented were still used 3 months later. The fall rate (per 1000 participant-days) was 4.87 during the control period and 4.31 during the posttreatment period. After adjusting for covariates and secular trend, there was no significant difference in fall rate (incidence rate ratio [IRR] 0.97, 95% CI 0.66-1.42). After excluding data collected during a hiatus in the intervention due to COVID-19, the reduction in fall rate was not significant (IRR 0.93, 95% CI 0.62-1.40). CONCLUSIONS: Although HARP did not significantly reduce the rate of falls, this pragmatic study showed that the program was feasible to deliver in low-income senior housing and was acceptable among residents. There was effective collaboration between researchers and community agency staff.

The Association Between Postural Sway and Preclinical Alzheimer Disease Among Community-Dwelling Older Adults.

BACKGROUND: It is unknown whether older adults with preclinical Alzheimer disease (AD) experience changes in postural sway compared with those without preclinical AD. The purpose of this study was to understand the effect of dual tasking on standing balance, or postural sway, for people with and without preclinical AD. METHODS: A cross-sectional analysis of baseline data from a longitudinal cohort study. Participants were cognitively normal older adults with and without preclinical AD. Postural sway (path length) was tested using a force plate under standard and dual task balance conditions. Dual task cost (DTC) was calculated to examine performance change in balance conditions. Logistic regression models were used to predict preclinical AD status as a function of DTC. RESULTS: 203 participants (65 preclinical AD+) were included. DTC for path length was significantly greater for participants with preclinical AD (DTC path length mean difference 19.8, 95% CI 2.6-37.0, t(201) = 2.29, p = .024). Greater DTC was significantly associated with increased odds of having preclinical AD (adjusted odds ratio for a 20-unit increase in DTC 1.16, 95% CI 1.02-1.32). CONCLUSIONS: Older adults with preclinical AD are more likely to demonstrate significantly greater DTC in postural sway than those without preclinical AD. Dual tasking should be integrated into balance and fall risk assessments and may inform early detection of preclinical AD.

The Relationship of Exercise, Psychosocial Factors, and Social Participation Among Adults Aging With Long-Term Physical Disability: A Cross-Sectional Study.

PURPOSE: This study investigated the relationships among exercise engagement, psychosocial factors, and social participation for adults aging with physical disabilities (AAwPD). DESIGN: A cross-sectional study within a community-based cohort study of participation among AAwPD was conducted. SETTING: A comprehensive survey was administered online or via telephone. PARTICIPANTS: Participants were 474 individuals between the ages of 45-65, primarily living in the Midwestern United States, who reported living with a physical disability for at least 5 years. METHOD: Survey questions created based on prior consolidation of activity domains assessed exercise engagement. Psychosocial health and social participation were measured using the Patient Reported Outcomes Measurement Information System. Chi-square tests, t-tests, and a general linear model were used to examine differences between exercisers and non-exercisers. RESULTS: Participants who exercised reported less pain (P < .001), fatigue (P < .001), and depression (P < .001) and greater self-efficacy for management of chronic conditions (P = .002), satisfaction with participation in social roles and activities (P < .001), and ability to participate in social roles and activities (P < .001) compared with non-exercising participants. CONCLUSIONS: AAwPD who exercised reported fewer secondary conditions and greater social participation. Although causal relationships cannot be drawn, and the frequency, duration, and intensity of exercise were not examined, this study lays important groundwork for future research to determine the health and participation benefits of exercise for AAwPD. Future studies should also focus on the development of exercise interventions to support successful aging with disability.

Down syndrome and Alzheimer's disease: A scoping review of functional performance and fall risk.

Introduction: Alzheimer's disease (AD) occurs in aging adults with Down syndrome (DS) at a higher prevalence and an earlier age than in typical aging adults. As with the general aging adult population, there is an urgent need to understand the preclinical and early phases of AD progression in the adult population with DS. The aim of this scoping review was to synthesize the current state of the evidence and identify gaps in the literature regarding functional activity performance and falls and their significance to disease staging (i.e., mild, moderate, and severe defined staging criteria) in relation to Alzheimer's disease and related dementias (ADRD) in adults with DS. Methods: This scoping review included six electronic databases (e.g., PsycInfo, Academic Search Complete, CINAHL, COCHRANE Library, MEDLINE, and PubMed). Eligible studies included participants with DS ≥25 years of age, studies with functional measures and/or outcomes (e.g., activities of daily living, balance, gait, motor control, speech, behavior, and cognition; falls; and fall risks), and studies that investigated AD pathology and implications. Results: Fourteen eligible studies were included and categorized through a thematic analysis into the following themes: (1) physical activity and motor coordination (PAMC), (2) cognition, (3) behavior, and (4) sleep. The studies indicated how functional activity performance and engagement may contribute to early identification of those at risk of cognitive decline and AD development and/or progression. Discussion: There is a need to expand the research regarding ADRD pathology relative to functional outcomes in adults with DS. Functional measures related to disease staging and cognitive impairment are essential to understanding how AD progression is characterized within real-world settings. This scoping review identified the need for additional mixed-methods research to examine the use of assessment and intervention related to function and its detection of cognitive decline and AD progression.

Precipitating Mechanisms of Falls in Preclinical Alzheimer's Disease.

Background: Individuals with Alzheimer's disease (AD) are more than twice as likely to incur a serious fall as the general population of older adults. Although AD is commonly associated with cognitive changes, impairments in other clinical measures such as strength or functional mobility (i.e., gait and balance) may precede symptomatic cognitive impairment in preclinical AD and lead to increased fall risk. Objective: To examine mechanisms (i.e., functional mobility, cognition, AD biomarkers) associated with increased falls in cognitively normal older adults. Methods: This 1-year study was part of an ongoing longitudinal cohort study. We examined the relationships among falls, clinical measures of functional mobility and cognition, and neuroimaging AD biomarkers in cognitively normal older adults. We also investigated which domain(s) best predicted fall propensity and severity through multiple regression models. Results: A total of 182 older adults were included (mean age 75 years, 53% female). A total of 227 falls were reported over the year; falls per person ranged from 0-16 with a median of 1. Measures of functional mobility were the best predictors of fall propensity and severity. Cognition and AD biomarkers were associated with each other but not with the fall outcome measures. Conclusion: These results suggest that, although subtle changes in cognition may be more closely associated with AD neuropathology, functional mobility indicators better predict falls in cognitively normal older adults. This study adds to our understanding of the mechanisms underlying falls in older adults and could lead to the development of targeted fall prevention strategies.

Retention of Study Partners in Longitudinal Studies of Alzheimer Disease.

BACKGROUND: Study partners are required for all participants at Alzheimer's Disease Research Centers (ADRCs). Study partners' attitudes and beliefs may contribute to missed visits and negatively impact retention of participants in longitudinal AD studies. OBJECTIVE: Study partners (N = 212) of participants (Clinical Dementia Rating® [CDR]≤2) at four ADRCs were randomly surveyed to examine their facilitators and barriers to continued participation in AD studies. METHODS: Reasons for participation were analyzed with factor analysis and regression analysis. Effects of complaints and goal fulfillment on attendance were estimated with fractional logistic models. Open-ended responses were characterized with a Latent Dirichlet Allocation topic model. RESULTS: Study partners participated for personal benefit and altruism. They emphasized personal benefits more when their participants had a CDR > 0 than when they had a CDR = 0. This difference declined with participant age. The majority of study partners rated their ADRC participation as positive and meeting their goals. Although half reported at least one complaint, very few regretted participating. Those who reported that ADRC participation fulfilled their goals or had fewer complaints were more likely to have perfect attendance. Study partners requested more feedback about test results and better management of study visits. CONCLUSION: Study partners are motivated by both personal and altruistic goals. The salience of each goal depends on their trust in researchers and the participant's cognitive status and age. Retention may improve with perceived goal fulfillment and fewer complaints. Potential areas for improving retention are providing more information about the participant's test results and better management of study visits.

Gut microbiome composition may be an indicator of preclinical Alzheimer's disease.

Alzheimer's disease (AD) pathology is thought to progress from normal cognition through preclinical disease and ultimately to symptomatic AD with cognitive impairment. Recent work suggests that the gut microbiome of symptomatic patients with AD has an altered taxonomic composition compared with that of healthy, cognitively normal control individuals. However, knowledge about changes in the gut microbiome before the onset of symptomatic AD is limited. In this cross-sectional study that accounted for clinical covariates and dietary intake, we compared the taxonomic composition and gut microbial function in a cohort of 164 cognitively normal individuals, 49 of whom showed biomarker evidence of early preclinical AD. Gut microbial taxonomic profiles of individuals with preclinical AD were distinct from those of individuals without evidence of preclinical AD. The change in gut microbiome composition correlated with ß-amyloid (Aß) and tau pathological biomarkers but not with biomarkers of neurodegeneration, suggesting that the gut microbiome may change early in the disease process. We identified specific gut bacterial taxa associated with preclinical AD. Inclusion of these microbiome features improved the accuracy, sensitivity, and specificity of machine learning classifiers for predicting preclinical AD status when tested on a subset of the cohort (65 of the 164 participants). Gut microbiome correlates of preclinical AD neuropathology may improve our understanding of AD etiology and may help to identify gut-derived markers of AD risk.