Utility of the Dependence Scale in dementia: validity, meaningfulness, and health economic considerations

Clinically Important Benefits and Harms of Monoclonal Antibodies Targeting Amyloid for the Treatment of Alzheimer Disease: A Systematic Review and Meta-Analysis

PURPOSE

We conducted a meta-analysis to evaluate clinically meaningful benefits and harms of monoclonal antibodies targeting amyloid in patients with Alzheimer dementia.

METHODS

We searched PubMed, Cochrane CENTRAL, and 5 trial registries, as well as the reference lists of identified studies. We included randomized controlled trials comparing a monoclonal antibody with placebo at a dose consistent with that used in phase 3 trials or for Food and Drug Administration approval. Studies had to report at least 1 clinically relevant benefit or harm. Data were extracted independently by at least 2 researchers for random effects meta-analysis. Changes in cognitive and functional scales were compared between groups, and each difference was assessed to determine if it met the minimal clinically important difference (MCID).

RESULTS

We identified 19 publications with 23,202 total participants that evaluated 8 anti-amyloid antibodies. There were small improvements over placebo in the Alzheimer's Disease Assessment Scale (ADAS)-Cog-11 to -14 score (standardized mean difference = -0.07; 95% CI, -0.10 to -0.04), Mini Mental State Examination score (0.32 points; 95% CI, 0.13 to 0.50), and Clinical Dementia Rating-Sum of Boxes scale score (mean difference =-0.18 points; 95% CI, -0.34 to -0.03), and the combined functional scores (standardized mean difference = 0.09; 95% CI, 0.05 to 0.13). None of the changes, including those for lecanemab, aducanumab, and donanemab, exceeded the MCID. Harms included significantly increased risks of amyloid-related imaging abnormalities (ARIA)-edema (relative risk [RR] = 10.29; number needed to harm [NNH] = 9), ARIA-hemorrhage (RR = 1.74; NNH = 13), and symptomatic ARIA-edema (RR = 24.3; NNH = 86).

CONCLUSIONS

Although monoclonal antibodies targeting amyloid provide small benefits on cognitive and functional scales in patients with Alzheimer dementia, these improvements are far below the MCID for each outcome and are accompanied by clinically meaningful harms.

Assessing Quality of Life, Economic Burden, and Independence Across the Alzheimer's Disease Continuum Using Patient-Caregiver Dyad Surveys

Background

Alzheimer's disease (AD) and mild cognitive impairment (MCI) have negative quality of life (QoL) and economic impacts on patients and their caregivers and may increase along the disease continuum from MCI to mild, moderate, and severe AD.

Objective

To assess how patient and caregiver QoL, indirect and intangible costs are associated with MCI and AD severity.

Methods

An on-line survey of physician-identified patient-caregiver dyads living in the United States was conducted from June-October 2022 and included questions to both patients and their caregivers. Dementia Quality of Life Proxy, the Care-related Quality of Life, Work Productivity and Activity Impairment, and Dependence scale were incorporated into the survey. Regression analyses investigated the association between disease severity and QoL and cost outcomes with adjustment for baseline characteristics.

Results

One-hundred patient-caregiver dyads were assessed with the survey (MCI, n = 27; mild AD, n = 27; moderate AD, n = 25; severe AD, n = 21). Decreased QoL was found with worsening severity in patients (p < 0.01) and in unpaid (informal) caregivers (n = 79; p = 0.02). Dependence increased with disease severity (p < 0.01). Advanced disease severity was associated with higher costs to employers (p = 0.04), but not with indirect costs to caregivers. Patient and unpaid caregiver intangible costs increased with disease severity (p < 0.01). A significant trend of higher summed costs (indirect costs to caregivers, costs to employers, intangible costs to patients and caregivers) in more severe AD was observed (p < 0.01).

Conclusions

Patient QoL and functional independence and unpaid caregiver QoL decrease as AD severity increases. Intangible costs to patients and summed costs increase with disease severity and are highest in severe AD.

Exploring the relationship between patient-relevant outcomes and Alzheimer's disease progression assessed using the clinical dementia rating scale: a systematic literature review

Background

People with Alzheimer's disease (AD) have difficulties in performing activities of daily living (ADLs) as the disease progresses, commonly experience neuropsychiatric symptoms (NPS), and often have comorbidities such as cardiovascular disease. These factors all contribute to a requirement for care and considerable healthcare costs in AD. The Clinical Dementia Rating (CDR) scale is a widely used measure of dementia staging, but the correlations between scores on this scale and patient-/care partner-relevant outcomes have not been characterized fully. We conducted a systematic literature review to address this evidence gap.

Methods

Embase, MEDLINE, and the Cochrane Library were searched September 13, 2022, to identify published studies (no restriction by date or country) in populations with mild cognitive impairment due to AD or AD dementia. Studies of interest reported data on the relationships between CDR Global or CDR-Sum of Boxes (CDR-SB) scores and outcomes including NPS, comorbidities, ADLs, nursing home placement, healthcare costs, and resource use.

Results

Overall, 58 studies met the inclusion criteria (42 focusing on comorbidities, 14 on ADLs or dependence, five on nursing home placement, and six on economic outcomes). CDR/CDR-SB scores were correlated with the frequency of multiple NPS and with total scores on the Neuropsychiatric Inventory. For cardiovascular comorbidities, no single risk factor was consistently linked to AD progression. Increasing CDR/CDR-SB scores were correlated with decline in multiple different measures of ADLs and were also associated with nursing home placement and increasing costs of care.

Conclusion

NPS, ADLs, and costs of care are clearly linked to AD progression, as measured using CDR Global or CDR-SB scores, from the earliest stages of disease. This indicates that scores derived from the CDR are a meaningful way to describe the severity and burden of AD for patients and care partners across disease stages.

Neuropsychiatric Symptoms and Trajectories of Dependence and Cognition in a Sample of Community-dwelling Older Adults with Dementia

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS), including psychotic symptoms (hallucinations, illusions, delusions), agitation/aggression, and depressed mood, are common in individuals with Alzheimer's disease (AD) and predict poorer outcomes, including faster disease progression. We aimed to evaluate associations between NPS and cognition and dependence in a multi-ethnic sample of community-dwelling older adults with AD.

METHODS

Predictors 3 (P3) is a cohort study of AD disease courses recruiting older adults aged 65 and above residing in upper Manhattan. A total of 138 of 293 participants had probable AD at the study baseline. We fit linear mixed models to examine longitudinal associations of time-varying NPS (psychotic symptoms, agitation/aggression, and depressed mood) with dependence and cognition, adjusted for race-ethnicity, sex, education, age, clinical dementia rating score, APOE-ε4, and comorbidity burden; separate interaction models were fit for age, Hispanic ethnicity, and sex.

RESULTS

Psychotic symptoms were associated with faster rates of increasing dependence and declining cognition over time, agitation/aggression with faster rates of declining cognition, and depressed mood with faster rates of increasing dependence. Among psychotic symptoms, delusions, but not hallucinations or illusions, were associated with worse outcome trajectories. Depressed mood predicted an accelerated increase in dependence in males but not females.

CONCLUSION

Our results confirm and extend prior results in clinic-based samples. The presence of NPS was associated with worse trajectories of dependence and cognition in this muti-ethnic sample of older adults with AD. Importantly, sex modified the association between depressed mood and dependence. Our results on NPS as predictors of differential AD progression in a community-dwelling, ethnically diverse sample serve to better inform the clinical care of patients and the future development of AD therapies.

Evaluating the Effectiveness of Community-Based Dementia Caregiver Intervention on Caregiving Burden, Depression, and Attitude Toward Dementia: A Quasi-experimental Study

Objective

Accumulating evidence of the effects of dementia caregiving on individuals, society, and health has generated intervention studies to reduce the stress among family caregivers of people with dementia. This study aims to evaluate the effectiveness of a family support program, community-based dementia caregiver intervention (CDCI), among family caregivers of people with dementia compared with a control group (no intervention).

Patients and Methods

This study is a quasi-experimental, non-randomized controlled trial conducted in six dementia relief centers of a community healthcare center in Korea. Family caregivers of 83 patients with dementia were recruited; of these 78 were included in the final study, with 40 in the intervention group and 38 in the control group. Analysis of covariance (ANCOVA) was used to compare the mean difference in the scores of the total short-form Zarit Burden Interview (SZBI), personal strain, role strain, depression, and attitude between the groups.

Results

Compared with controls, in the intervention group, the adjusted mean score of personal strain (F = 4.353, t = 0.041) and attitude toward dementia (F = 10.284, t = 0.002) differed significantly after the intervention, with a small to moderate effect. There was no significant difference in the total SZBI, role strain, or depression mean score.

Conclusion

The findings suggest that CDCI may be an effective intervention strategy to reduce personal strain and enhance the attitudes of family caregivers of people with dementia.

Neuropsychological Predictors of Severe Functional Dependency in a Multiethnic Community Cohort of Individuals with Alzheimer's Disease

To assess the predictive value of neuropsychological tests for severe dependency in Alzheimer's disease as defined by the Equivalent Institutional Care Rating Scale, in a multiethnic, community cohort. The sample included 146 elders from the Predictors 3 cohort. Cox proportional hazard models tested the predictive value of each neuropsychological test at baseline on relative risk of meeting severe dependency. Higher semantic processing and memory test scores at baseline were associated with lower risk of meeting severe dependency in the adjusted Cox models. The integrity of semantic processing and memory abilities in dementia appears to predict time to severe functional dependency.

Dependence Clusters in Alzheimer Disease and Medicare Expenditures: A Longitudinal Analysis From the Predictors Study

INTRODUCTION

Dependence in Alzheimer disease has been proposed as a holistic, transparent, and meaningful representation of disease severity. Modeling clusters in dependence trajectories can help understand changes in disease course and care cost over time.

METHODS

Sample consisted of 199 initially community-living patients with probable Alzheimer disease recruited from 3 academic medical centers in the United States followed for up to 10 years and had ≥2 Dependence Scale recorded. Nonparametric K-means cluster analysis for longitudinal data (KmL) was used to identify dependence clusters. Medicare expenditures data (1999-2010) were compared between clusters.

RESULTS

KmL identified 2 distinct Dependence Scale clusters: (A) high initial dependence, faster decline, and (B) low initial dependence, slower decline. Adjusting for patient characteristics, 6-month Medicare expenditures increased over time with widening between-cluster differences.

DISCUSSION

Dependence captures dementia care costs over time. Better characterization of dependence clusters has significant implications for understanding disease progression, trial design and care planning.

Caregivers' Sense of Coherence: Implications on Direct and Indirect Costs of Dementia Care

BACKGROUND

Dementia care is associated with physical, emotional, and monetary impact on the informal carers providing unpaid care. Differences in the personal characteristics of caregivers may help explain the variations in the costs of dementia care.

OBJECTIVE

The aim of this study was to analyze the effect of caregivers' sense of coherence (SOC) on direct and indirect costs in dementia care.

METHODS

A cross-sectional study was conducted in community dwelling caregivers of patients with Alzheimer's disease. Data of healthcare services were obtained from clinical registries, and information was collected from caregivers regarding their use of social care resources and time spent caregiving. The transformation of all costs into Euros was made assigning a fixed cost of 10.29 € /h and 16.24 € /h for assisting in instrumental and basic activities of daily living, respectively. Caregivers' SOC was assessed using the Orientation to Life Questionnaire (OLQ-13). Adjusted regression models were developed, with different types of costs as dependent variables.

RESULTS

A sample of 147 caregivers was recruited. The mean OLQ-13 score was 73.3 points (SD = 11.6). The regression models showed a small association between caregivers' SOC and direct costs, mainly linked to the use of social care resources (r2 = 0.429; β= -15.6 € /month), and a greater association between SOC and indirect costs (r2 = 0.562; β= -222.3 € /month).

CONCLUSION

Increasing caregivers' SOC could reduce dementia care costs by decreasing the use of social care resources and caregiving time.