Observation of Patient and Caregiver Burden Associated with Early Alzheimer's Disease in the United States: Design and Baseline Findings of the GERAS-US Cohort Study1

Evaluating Elements of the Care Partner Experience in Individuals Who Care for People with Alzheimer's Disease Across the Severity Spectrum

INTRODUCTION

Non-professional care partners play an important and often evolving role in the care of persons living with Alzheimer's disease (PLWAD). We investigated two elements of the care partner experience, namely time and strain incurred by care partners providing care to PLWAD across the severity spectrum.

METHODS

Data gathered from the Alzheimer's Disease Patient and Caregiver Engagement (AD PACE) What Matters Most (WMM) study series were analyzed to determine how much time care partners spent providing care to PLWAD based on where the care recipients lived. Additionally, quantitative assessments of weekly hours providing care and the strain experienced by care partners were conducted using the UsAgainstAlzheimer's A-LIST Insights Series survey, which included the Modified Caregiver Strain Index (MCSI). Finally, a targeted literature review was conducted to contextualize findings and characterize the existing literature landscape.

RESULTS

Care partners in the AD PACE WMM studies (n = 139) spent significantly more hours providing care for recipients who lived with someone (mean ± standard deviation [SD], 57.3 ± 44.3 h/week) than for recipients who lived alone (26.0 ± 12.0 h/week) (P = 0.0096) or lived in assisted living/nursing home (23.6 ± 14.4 h/week) (P = 0.0002). In the A-LIST Insights Series survey, care partners provided an overall mean (± SD) 58.1 ± 53.0 h of direct care each week, with caregiving hours increasing with increasing severity of AD/AD-related dementias (AD/ADRD). Additionally, care partners for recipients with mild (n = 14), moderate (n = 111), and severe AD/ADRD (n = 91) had overall mean MCSI scores of 9.0 ± 3.8 (range 2-14), 13.3 ± 4.8 (range 4-23), and 17.5 ± 5.3 (range 4-26), respectively, with higher scores suggesting greater care partner strain.

CONCLUSIONS

Persons living with AD require increasing levels of care along the spectrum of disease, and even individuals with early disease need care from partners. Early interventions that slow progression of AD and programs that improve family function may have beneficial impact on the experiences of care partners for recipients with mild, moderate, or severe AD.

Potential Impact of Slowing Disease Progression in Early Symptomatic Alzheimer's Disease on Patient Quality of Life, Caregiver Time, and Total Societal Costs: Estimates Based on Findings from GERAS-US Study

Background

Impact of Alzheimer's disease (AD) progression on patient health-related quality of life (HRQoL), caregiver time, and societal costs is not well characterized in early AD.

Objective

To assess the association of change in cognition with HRQoL, caregiver time, and societal costs over 36 months, and estimate the impact of slowing disease progression on these outcomes.

Methods

This post-hoc analysis included patients with amyloid-positive mild cognitive impairment (MCI) and mild AD dementia (MILD AD) from the 36-month GERAS-US study. Disease progression was assessed using the Mini-Mental State Examination score. Change in outcomes associated with slowing AD progression was estimated using coefficients from generalized linear models.

Results

At baseline, 300 patients had MCI and 317 had MILD AD. Observed natural progression over 36 months was associated with: 5.1 point decline in the Bath Assessment of Subjective Quality of Life in Dementia (BASQID) score (for HRQoL), increase in 1,050 hours of total caregiver time, and $8,504 total societal costs for MCI; 6.6 point decline in the BASQID score, increase in 1,929 hours of total caregiver time, and $12,795 total societal costs for MILD AD per person. Slowing AD progression by 30% could result in per person savings in HRQoL decline, total caregiver time, and total societal costs: for MCI: 1.5 points, 315 hours, and $2,638; for MILD AD: 2.0 points, 579 hours, and $3,974.

Conclusions

Slowing AD progression over 36 months could slow decline in HRQoL and save caregiver time and societal cost in patients with MCI and MILD AD.

Alzheimer`s disease mortality in the United States: Cross-sectional analysis of county-level socio-environmental factors

BACKGROUND

Geographical disparities in mortality among Alzheimer`s disease (AD) patients have been reported and complex sociodemographic and environmental determinants of health (SEDH) may be contributing to this variation. Therefore, we aimed to explore high-risk SEDH factors possibly associated with all-cause mortality in AD across US counties using machine learning (ML) methods.

METHODS

We performed a cross-sectional analysis of individuals ≥65 years with any underlying cause of death but with AD in the multiple causes of death certificate (ICD-10,G30) between 2016 and 2020. Outcomes were defined as age-adjusted all-cause mortality rates (per 100,000 people). We analyzed 50 county-level SEDH and Classification and Regression Trees (CART) was used to identify specific county-level clusters. Random Forest, another ML technique, evaluated variable importance. CART`s performance was validated using a "hold-out" set of counties.

RESULTS

Overall, 714,568 individuals with AD died due to any cause across 2,409 counties during 2016-2020. CART identified 9 county clusters associated with an 80.1% relative increase of mortality across the spectrum. Furthermore, 7 SEDH variables were identified by CART to drive the categorization of clusters, including High School Completion (%), annual Particulate Matter 2.5 Level in Air, live births with Low Birthweight (%), Population under 18 years (%), annual Median Household Income in US dollars ($), population with Food Insecurity (%), and houses with Severe Housing Cost Burden (%).

CONCLUSION

ML can aid in the assimilation of intricate SEDH exposures associated with mortality among older population with AD, providing opportunities for optimized interventions and resource allocation to reduce mortality among this population.

Disease progression and costs at the 3-year follow-up of the GERAS-US study

Introduction

GERAS-US prospectively characterized clinical and economic outcomes of early symptomatic Alzheimer's disease (AD). Societal cost changes were examined in amyloid-positive patients with mild cognitive impairment due to AD (MCI) and mild dementia due to AD (MILD).

Methods

Cognition, function, and caregiver burden were assessed using Mini-Mental State Examination (MMSE), Cognitive Function Index (CFI), and Zarit Burden Interview, respectively. Costs are presented as least square mean for the overall population and for MCI versus MILD using mixed model repeated measures.

Results

MMSE score and CFI worsened. Total societal costs (dollars/month) for MCI and MILD, respectively, were higher at baseline ($2430 and $4063) but steady from 6 ($1977 and $3032) to 36 months ($2007 and $3392). Direct non-medical costs rose significantly for MILD. Caregiver burden was higher for MILD versus MCI at 12, 18, and 24 months.

Discussion

Function and cognition declined in MILD. Non-medical costs reflect the increasing impact of AD even in its early stages.

HIGHLIGHTS

In the GERAS-US study, total societal costs for patients with mild cognitive impairment due to Alzheimer's disease (MCI) and mild dementia due to Alzheimer's disease (MILD) were higher at baseline but steady from 6 to 36 months.Mini-Mental State Examination (MMSE) and Cognitive Function Index (CFI) worsened; the rate of decline was significant for patients with MILD but not for those with MCI.There was a rise in direct non-medical costs at 36 months for patients with MILD.Caregiver burden was higher for MILD versus MCI at 12, 18, and 24 months.Slowing the rate of disease progression in this early symptomatic population may allow patients to maintain their ability to carry out everyday activities longer.

Clinical and Economic Assessment in Early-Stage Dementia by Severity and Amyloid-β Status: A 5-Year Retrospective Claims Study of GERAS-US Patients

BACKGROUND

The high burden of dementia and Alzheimer's disease (AD) increases substantially as disease progresses. Characterizing early patterns of health care utilization among patients who develop cognitive impairment may deepen our understanding of early disease trajectory and potentially facilitate timely diagnosis and management.

OBJECTIVE

Describe clinical characteristics, healthcare utilization, and costs in early-stage dementia by disease severity and amyloid-β status before enrollment in an observational study (GERAS-US).

METHODS

Consented patients' GERAS-US data were linked to available five-years of Medicare claims history before GERAS-US enrollment. Clinical characteristics, comorbidity, and pre-/post-diagnosis healthcare use and costs were assessed. Continuous and categorical variables were compared between severity and amyloid-status cohorts using t-test and Chi-square statistics; linear regression models were used to compare cost and utilization measures after adjusting for differences in patients' observation time. Relative likelihood of observed diagnoses, comorbidity, and prescription drug use among cohorts were presented as OR and 90% confidence interval (CI).

RESULTS

Of 174 patients clinically diagnosed with early dementia (mild cognitive impairment (MCI): 101; mild dementia (MILD): 73), 55% were amyloid-positive. Memory loss was more likely in MILD versus MCI (OR:1.85, 90% CI 1.10-3.09) and in amyloid-positive versus amyloid-negative cohorts (OR:1.98, 90% CI 1.19-3.29). Mean annual healthcare costs after cognitive impairment/dementia diagnosis were significantly higher for MILD versus MCI ($1191 versus $712, p = 0.067) and amyloid-negative versus amyloid-positive ($1281 versus $701, p = 0.034). Diabetes was more prevalent in MILD and amyloid-negative cohorts.

CONCLUSION

Comorbidity and economic burden increased in earliest stages of MCI and MILD and were higher in patients who were amyloid-negative.

"I know that my role is going to change": a mixed-methods study of the relationship between amyloid-β PET scan results and caregiver burden

BACKGROUND

Caregiver burden consists of disease specific and perceived stressors, respectively referred to as objective and subjective indicators of burden, and is associated with negative outcomes. Previous research has found that care partners to persons living with cognitive impairment and elevated levels of amyloid-β, as measured by a positron emission tomography (PET) scan, may experience caregiver burden.

AIMS

To elucidate the relationship between amyloid scan results and subjective and objective indicators of burden.

METHODS

A parallel mixed-methods design using survey data from 1338 care partners to persons with mild cognitive impairment (MCI) and dementia who received an amyloid scan from the CARE-IDEAS study; and semi-structured interviews with a subsample of 62 care partners. Logistic regression models were used to investigate objective factors associated with caregiver burden. A thematic analysis of semi-structured interviews was used to investigate subjective indicators by exploring care partners' perceptions of their role following an amyloid scan.

RESULTS

Elevated amyloid was not associated with burden. However, the scan result influenced participants perceptions of their caregiving role and coping strategies. Care partners to persons with elevated amyloid expected increasing responsibility, whereas partners to persons without elevated amyloid and mild cognitive impairment did not anticipate changes to their role. Care partners to persons with elevated amyloid reported using knowledge gained from the scan to develop coping strategies. All care partners described needing practical and emotional support.

CONCLUSIONS

Amyloid scans can influence subjective indicators of burden and present the opportunity to identify and address care partners' support needs.

APOEε4 Genotype Is Related to Brain Amyloid Among Mexican Americans in the HABS-HD Study

Introduction

Despite the fact that Hispanics are expected to experience the greatest increase in Alzheimer's disease (AD) and related dementias (ADRDs) by 2060, very little data is available regarding the fundamental biomarkers of AD among Mexican Americans who reflect the majority of Hispanics in the U.S. Here we sought to examine the link between APOEε4 genotype and brain amyloid among Mexican Americans as compared to non-Hispanic white participants from the Health & Aging Brain Study - Health Disparities (HABS-HD) cohort.

Methods

PET amyloid (florbetaben) data were analyzed from 105 Mexican American and 150 non-Hispanic white participants.

Results

Among Mexican Americans, APOEε4 genotype presence was associated with Global SUVR (p = 0.003) as well as amyloid burden in the frontal (p < 0.001), lateral parietal (p = 0.003), lateral temporal (p = 0.008) and anterior-posterior cingulate (p = 0.005) regions of interest (ROIs). Among non-Hispanic white participants, APOEε4 genotype presence was associated with Global SUVR (p < 0.001) as well as amyloid burden in the frontal (p < 0.001), lateral parietal (p < 0.001), lateral temporal (p < 0.001) and anterior-posterior cingulate (p < 0.001) regions of interest (ROIs). The association between APOEε4 genotype and cerebral amyloid was strongest among non-Hispanic white participants.

Discussion/Conclusion

Despite the fact that the APOEε4 genotype is significantly less frequent among Mexican Americans, its presence remains to be a significant risk factor among this group for AD pathological burden across all regions. Additional work is needed to understand the presence, progression, and clinical impact of brain amyloid among Mexican Americans.

The Humanistic and Economic Burden of Alzheimer's Disease

Alzheimer's disease (AD) is the leading cause of cognitive impairment and dementia in older individuals (aged ≥ 65 years) throughout the world. As a result of these progressive deficits in cognitive, emotional, and physical function, AD dementia can cause functional disability and loss of independence. To gain a deeper understanding of the recent literature on the burden of AD, including that of mild cognitive impairment (MCI) due to AD, we conducted a comprehensive targeted review of the PubMed-indexed literature (2014 to 2021) to examine the humanistic and economic burden of AD (including MCI) in North America, Europe, and Asia. Our literature review identified a range of factors associated with quality of life (QoL): some factors were positively associated with QoL, including caregiver relationship, religiosity, social engagement, and ability to engage in activities of daily living (ADL), whereas other factors such as neuropsychiatric symptoms were associated with poorer QoL. While patient- and proxy-rated QoL are highly correlated in patients with early AD dementia, proxy-rated QoL declines more substantially as severity worsens. The maintenance of self-reported QoL in patients with more severe AD dementia may be due to lack of awareness or to adaptation to circumstances. Compared to persons with normal cognition, MCI is associated with a greater cost burden, and individuals with MCI exhibit worse QoL. Key drivers of the societal economic burden of AD include disease severity, dependence level, institutionalization, and comorbidity burden. Evaluation of the impact of a hypothetical disease-modifying treatment delaying the progression from MCI to AD has suggested that such a treatment may result in cost savings.

Neurodegeneration from the AT(N) framework is different among Mexican Americans compared to non-Hispanic Whites: A Health & Aging Brain among Latino Elders (HABLE) Study

INTRODUCTION

We sought to examine a magnetic resonance imaging (MRI)-based marker of neurodegeneration from the AT(N) (amyloid/tau/neurodegeneration) framework among a multi-ethnic, community-dwelling cohort.

METHODS

Community-dwelling Mexican Americans and non-Hispanic White adults and elders were recruited. All participants underwent comprehensive assessments including an interview, functional exam, clinical labs, informant interview, neuropsychological testing and 3T MRI of the brain. A neurodegeneration MRI meta-region of interest (ROI) biomarker for the AT(N) framework was calculated.

RESULTS

Data were examined from n = 1305 participants. Mexican Americans experienced N at significantly younger ages. The N biomarker was significantly associated with cognitive outcomes. N was significantly impacted by cardiovascular factors (e.g., total cholesterol, low-density lipoprotein) among non-Hispanic Whites whereas diabetes (glucose, HbA1c, duration of diabetes) and sociocultural (household income, acculturation) factors were strongly associated with N among Mexican Americans.

DISCUSSION

The prevalence, progression, timing, and sequence of the AT(N) biomarkers must be examined across diverse populations.

Quality of life in caregivers of patients receiving chimeric antigen receptor T-cell therapy

OBJECTIVE

Informal family caregivers provide critical support for patients receiving chimeric antigen receptor (CAR) T-cell therapy. However, caregivers' experiences are largely unstudied. This study examined quality of life (QOL; physical functioning, pain, fatigue, anxiety, and depression), caregiving burden, and treatment-related distress in caregivers in the first 6 months after CAR T-cell therapy, when caregivers were expected to be most involved in providing care. Relationships between patients' clinical course and caregiver outcomes were also explored.

METHODS

Caregivers completed measures examining QOL and burden before patients' CAR T-cell therapy and at days 90 and 180. Treatment-related distress was assessed at days 90 and 180. Patients' clinical variables were extracted from medical charts. Change in outcomes was assessed using means and 99% confidence intervals. Association of change in outcomes with patient clinical variables was assessed with backward elimination analysis.

RESULTS

A total of 99 caregivers (mean age 59, 73% female) provided data. Regarding QOL, pain was significantly higher than population norms at baseline but improved by day 180 (p < .01). Conversely, anxiety worsened over time (p < .01). Caregiver burden and treatment-related distress did not change over time. Worsening caregiver depression by day 180 was associated with lower patient baseline performance status (p < .01). Worse caregiver treatment-related distress at day 180 was associated with lower performance status, intensive care unit admission, and lack of disease response at day 90 (ps < 0.01).

CONCLUSIONS

Some CAR T-cell therapy caregivers experience pain, anxiety, and burden, which may be associated patients' health status. Further research is warranted regarding the experience of CAR T-cell therapy caregivers.

Costs of Early Stage Alzheimer's Disease in the United States: Cross-Sectional Analysis of a Prospective Cohort Study (GERAS-US)1

BACKGROUND

Costs associated with early stages of Alzheimer's disease (AD; mild cognitive impairment [MCI] and mild dementia [MILD]) are understudied.

OBJECTIVE

To compare costs associated with MCI and MILD due to AD in the United States.

METHODS

Data included baseline patient/study partner medical history, healthcare resource utilization, and outcome assessments as part of a prospective cohort study. Direct, indirect, and total societal costs were derived by applying standardized unit costs to resources for the 1-month pre-baseline period (USD2017). Costs/month for MCI and MILD cohorts were compared using analysis of variance models. To strengthen the confidence of diagnosis, amyloid-β (Aβ) tests were included and analyses were replicated stratifying within each cohort by amyloid status [+ /-].

RESULTS

Patients (N = 1327) with MILD versus MCI had higher total societal costs/month ($4243 versus $2816; p < 0.001). These costs were not significantly different within each severity cohort by amyloid status. The largest fraction of overall costs were informal caregiver costs (45.1%) for the MILD cohort, whereas direct medical patient costs were the largest for the MCI cohort (39.0%). Correspondingly, caregiver time spent on basic activities of daily living (ADLs), instrumental ADLs, and supervision time was twice as high for MILD versus MCI (all p < 0.001).

CONCLUSION

Early AD poses a financial burden, and despite higher functioning among those with MCI, caregivers were significantly impacted. The major cost driver was the patient's clinical cognitive-functional status and not amyloid status. Differences were primarily due to rising need for caregiver support.