New International Pharmaco-Economic Collaboration on Alzheimer's Disease (IPECAD) Open-Source Model Framework for the Health Technology Assessment of Early Alzheimer's Disease Treatment: Development and Use Cases.

OBJECTIVES: Reimbursement decisions for new Alzheimer's disease (AD) treatments are informed by economic evaluations. An open-source model with intuitive structure for model cross-validation can support the transparency and credibility of such evaluations. We describe the new International Pharmaco-Economic Collaboration on Alzheimer's Disease (IPECAD) open-source model framework (version 2) for the health-economic evaluation of early AD treatment and use it for cross-validation and addressing uncertainty. METHODS: A cohort state-transition model using a categorized composite domain (cognition and function) was developed by replicating an existing reference model and testing it for internal validity. Then, features of existing Institute for Clinical and Economic Review (ICER) and Alzheimer's Disease Archimedes Condition-Event Simulator (AD-ACE) models assessing lecanemab treatment were implemented for model cross-validation. Additional uncertainty scenarios were performed on choice of efficacy outcome from trial, natural disease progression, treatment effect waning and stopping rules, and other methodological choices. The model is available open-source as R code, spreadsheet, and web-based version via https://github.com/ronhandels/IPECAD. RESULTS: In the IPECAD model incremental life-years, quality-adjusted life-years (QALY) gains and cost savings were 21% to 31% smaller compared with the ICER model and 36% to 56% smaller compared with the AD-ACE model. IPECAD model results were particularly sensitive to assumptions on treatment effect waning and stopping rules and choice of efficacy outcome from trial. CONCLUSIONS: We demonstrated the ability of a new IPECAD open-source model framework for researchers and decision makers to cross-validate other (Health Technology Assessment submission) models and perform additional uncertainty analyses, setting an example for open science in AD decision modeling and supporting important reimbursement decisions.

IPECAD Modeling Workshop 2023 Cross Comparison Challenge on Cost-Effectiveness Models in Alzheimer's Disease.

OBJECTIVES: Decision-analytic models assessing the value of emerging Alzheimer's disease (AD) treatments are challenged by limited evidence on short-term trial outcomes and uncertainty in extrapolating long-term patient-relevant outcomes. To improve understanding and foster transparency and credibility in modeling methods, we cross-compared AD decision models in a hypothetical context of disease-modifying treatment for mild cognitive impairment (MCI) due to AD. METHODS: A benchmark scenario (US setting) was used with target population MCI due to AD and a set of synthetically generated hypothetical trial efficacy estimates. Treatment costs were excluded. Model predictions (10-year horizon) were assessed and discussed during a 2-day workshop. RESULTS: Nine modeling groups provided model predictions. Implementation of treatment effectiveness varied across models based on trial efficacy outcome selection (CDR-SB, CDR-global, MMSE, FAQ) and analysis method (observed severity transitions, change from baseline, progression hazard ratio, or calibration to these). Predicted mean time in MCI ranged from 2.6-5.2 years for control strategy, and from 0.1-1.0 years for difference between intervention and control strategies. Predicted quality-adjusted life-year gains ranged from 0.0-0.6 and incremental costs (excluding treatment costs) from -US$66,897 to US$11,896. CONCLUSIONS: Trial data can be implemented in different ways across health-economic models leading to large variation in model predictions. We recommend 1) addressing the choice of outcome measure and treatment effectiveness assumptions in sensitivity analysis, 2) a standardized reporting table for model predictions, and 3) exploring the use of registries for future AD treatments measuring long-term disease progression to reduce uncertainty of extrapolating short-term trial results by health economic models.

BPSD Patterns in Patients With Severe Neuropsychiatric Disturbances: Insight From the RECAGE Study.

OBJECTIVE: Behavioral and psychological symptoms of dementia (BPSD) profiles vary depending on etiology in patients with mild-to-moderate BPSD. It is not known if similar differences exist in patients with severe BPSD. METHODS: We analyzed data collected at baseline in 398 patients with severe BPSD (NPI ≥ 32) and defined diagnosis of dementia (Alzheimer's disease [AD] 297; frontotemporal dementia [FTD] 39; Lewy body disease/Parkinsonian dementia [LBD/PD] 31; and vascular dementia [VD] 31) included in the European multicenter cohort RECAGE. RESULTS: Mean total NPI was 52.11 (18.55). LBD/PD patients demonstrated more hallucinations, more anxiety and more delusions than patients with other dementia. FTD patients had less delusions and more disinhibition than patients with other neurodegenerative disorders. These profiles overlapped partially with those reported in the literature in patients with less severe symptoms. CONCLUSION: Patients with severe BPSD display different and specific profiles of neuropsychiatric symptoms depending on dementia etiology.

Caregiver Burden and Quality of Life Across Alzheimer's Disease Severity Stages.

INTRODUCTION: The objective is to estimate the caregiver burden in terms of informal care time, health-related quality of life (HRQoL), and societal costs by disease severity (mild, moderate, or severe) and living situation (community-dwelling or institutionalized) of persons with AD (PwAD); and PwAD HRQoL. METHODS: Caregivers were recruited through an online panel provider in the Netherlands. The survey used validated instruments, including iMTA Valuation of Informal Care Questionnaire, CarerQoL, and EQ-5D-5L. RESULTS: One hundred two caregivers participated. PwADs received, on average, 26 hours of informal care per week. Informal care costs were higher for community-dwelling PwADs compared with institutionalized PwADs (€480 and €278, respectively). On the EQ-5D-5L, caregivers scored on average 0.797, reflecting a utility decrement of 0.065 compared with an age-matched population. Proxy-rated utility scores for PwADs decreased with increasing disease severity (0.455, 0.314, and 0.212 for mild, moderate, and severe AD, respectively). Institutionalised PwADs had lower utility scores than community-dwelling PwADs (0.590 vs. 0.421). There was no difference in informal care time, societal costs, CarerQol scores, and caregiver EQ-5D-5L scores between disease severities. CONCLUSION: The burden of AD extends to caregivers in terms of HRQoL and time investment, regardless of the disease severity of the target population. These impacts should be incorporated into the evaluation of new AD interventions.

Determinants of quality of life in family caregivers in MCI: a comparison with mild dementia.

OBJECTIVES: The aim of the current study was to investigate the health-related quality of life (HRQol) of the family caregiver in MCI, explore possible determinants and study possible differences with mild dementia. METHODS: This secondary data analysis included 145 persons with MCI and 154 persons with dementia and their family caregivers from two Dutch cohort studies. HRQoL was measured with the VAS of the EuroQol-5D-3L version. Regressions analyses were conducted to examine potential demographic and clinical determinants of the caregiver's HRQoL. RESULTS: The mean EQ5D-VAS in family caregivers of persons with MCI was 81.1 (SD 15.7), and did not significantly differ from family caregivers in mild dementia (81.9 (SD 13.0)). In MCI, patient measurements were not significantly associated with caregiver mean EQ5D-VAS. Concerning caregiver characteristics, being a spouse and a lower educational level were associated with a lower mean EQ5D-VAS (in a multiple linear regression model: unstandardized B -8.075, p = 0.013 and unstandardized B -6.162, p = 0.037 resp.). In mild dementia, the NPI item irritability showed an association with caregiver EQ5D-VAS in bivariate linear regression analyses. CONCLUSION: Results indicate that especially family caregiver characteristics seem to influence family caregiver HRQoL in MCI. Future research should include other potential determinants such as burden, coping strategies and relationship quality.

The value of maintaining cognition in patients with mild cognitive impairment: The innovation headroom and potential cost-effectiveness of roflumilast.

INTRODUCTION: Early health-technology assessment can support discussing scarce resource allocation among stakeholders. We explored the value of maintaining cognition in patients with mild cognitive impairment (MCI) by estimating: (1) the innovation headroom and (2) the potential cost effectiveness of roflumilast treatment in this population. METHODS: The innovation headroom was operationalized by a fictive 100% efficacious treatment effect, and the roflumilast effect on memory word learning test was assumed to be associated with 7% relative risk reduction of dementia onset. Both were compared to Dutch setting usual care using the adapted International Pharmaco-Economic Collaboration on Alzheimer's Disease (IPECAD) open-source model. RESULTS: The total innovation headroom expressed as net health benefit was 4.2 (95% bootstrap interval: 2.9-5.7) quality-adjusted life years (QALYs). The potential cost effectiveness of roflumilast was k€34 per QALY. DISCUSSION: The innovation headroom in MCI is substantial. Although the potential cost effectiveness of roflumilast treatment is uncertain, further research on its effect on dementia onset is likely valuable.

Cost-effectiveness models for Alzheimer's disease and related dementias: IPECAD modeling workshop cross-comparison challenge.

INTRODUCTION: The credibility of model-based economic evaluations of Alzheimer's disease (AD) interventions is central to appropriate decision-making in a policy context. We report on the International PharmacoEconomic Collaboration on Alzheimer's Disease (IPECAD) Modeling Workshop Challenge. METHODS: Two common benchmark scenarios, for the hypothetical treatment of AD mild cognitive impairment (MCI) and mild dementia, were developed jointly by 29 participants. Model outcomes were summarized, and cross-comparisons were discussed during a structured workshop. RESULTS: A broad concordance was established among participants. Mean 10-year restricted survival and time in MCI in the control group ranged across 10 MCI models from 6.7 to 9.5 years and 3.4 to 5.6 years, respectively; and across 4 mild dementia models from 5.4 to 7.9 years (survival) and 1.5 to 4.2 years (mild dementia). DISCUSSION: The model comparison increased our understanding of methods, data used, and disease progression. We established a collaboration framework to assess cost-effectiveness outcomes, an important step toward transparent and credible AD models.

The Impact of Amyloid PET Disclosure on Quality of Life in Patients With Young Onset Dementia.

INTRODUCTION: The impact of amyloid positron emission tomography (PET) imaging on patient health outcomes for individuals with dementia is unknown. In the present study, we explored the association between diagnostic outcome and clinician's level of certainty with quality of life (QoL) after [18F]flutemetamol PET results were disclosed in young onset dementia patients in a memory clinic cohort. METHODS: In 154 patients suspected of dementia, QoL was measured before and after [18F]flutemetamol PET results were disclosed. Multiple regression analyses were conducted with (changed) general and disease-specific QoL measures as dependent factors [QoL-Alzheimer disease (AD) and EQ-5D Dutch tariff] and etiological diagnosis and clinician's certainty as independent factors. RESULTS: (Change in) diagnosis of AD was associated to QOL in 2 of the 4 analyses (utility-based QoL ß=0.15, P=0.010; disease-specific QoL ß=2.0, P=0.037). Diagnostic certainty was associated to QOL in 1 of the 4 analyses (generic QoL ß=0.002, P=0.028). DISCUSSION: The diverse results in this explorative analysis do not reflect a univocal association between diagnosis, certainty, and QoL. Nevertheless, this result could be interpreted as a possible potential for advanced diagnostic technologies for AD, which requires confirmation in future research.

Dementia prevention: The potential long-term cost-effectiveness of the FINGER prevention program.

INTRODUCTION: The aim of this study was to estimate the potential cost-effectiveness of the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) program. METHODS: A life-time Markov model with societal perspective, simulating a cohort of people at risk of dementia reflecting usual care and the FINGER program. RESULTS: Costs were 1,653,275 and 1,635,346 SEK and quality-adjusted life years (QALYs) were 8.636 and 8.679 for usual care and the FINGER program, respectively, resulting in savings of 16,928 SEK (2023 US$) and 0.043 QALY gains per person, supporting extended dominance for the FINGER program. A total of 1623 dementia cases were avoided with 0.17 fewer person-years living with dementia. The sensitivity analysis confirmed the conclusions in most scenarios. DISCUSSION: The model provides support that programs like FINGER have the potential to be cost-effective in preventing dementia. Results at the individual level are rather modest, but the societal benefits can be substantial because of the large potential target population.

Clinical research in dementia: A perspective on implementing innovation.

The increasing global prevalence of dementia demands concrete actions that are aimed strategically at optimizing processes that drive clinical innovation. The first step in this direction requires outlining hurdles in the transition from research to practice. The different parties needed to support translational processes have communication mismatches; methodological gaps hamper evidence-based decision-making; and data are insufficient to provide reliable estimates of long-term health benefits and costs in decisional models. Pilot projects are tackling some of these gaps, but appropriate methods often still need to be devised or adapted to the dementia field. A consistent implementation perspective along the whole translational continuum, explicitly defined and shared among the relevant stakeholders, should overcome the "research-versus-adoption" dichotomy, and tackle the implementation cliff early on. Concrete next steps may consist of providing tools that support the effective participation of heterogeneous stakeholders and agreeing on a definition of clinical significance that facilitates the selection of proper outcome measures.

A validation study of the CarerQol instrument in informal caregivers of people with dementia from eight European countries.

PURPOSE: Informal care constitutes an important part of the total care for people with dementia. Therefore, the impact of the syndrome on their caregivers as well as that of health and social care services for people with dementia should be considered. This study investigated the convergent and clinical validity of the CarerQol instrument, which measures and values the impact of providing informal care, in a multi-country sample of caregivers for people with dementia. METHODS: Cross-sectional data from a sample of 451 respondents in eight European countries, collected by the Actifcare project, were evaluated. Convergent validity was analysed with Spearman's correlation coefficients and multivariate correlations between the CarerQol-7D utility score and dimension scores, and other similar quality of life measures such as CarerQol-VAS, ICECAP-O, and EQ-5D. Clinical validity was evaluated by bivariate and multivariate analyses of the degree to which the CarerQol instrument can differentiate between characteristics of caregivers, care receivers and caregiving situation. Country dummies were added to test CarerQol score differences between countries. RESULTS: The mean CarerQol utility score was 77.6 and varied across countries from 74.3 (Italy) to 82.3 (Norway). The scores showed moderate to strong positive correlations with the CarerQol-VAS, ICECAP-O, and EQ-5D health problems score of the caregiver. Multivariate regression analysis showed that various characteristics of the caregiver, care receiver and caregiving situation were associated with caregiver outcomes, but there was no evidence of a country-level effect. CONCLUSION: This study demonstrates the convergent and clinical validity of the CarerQol instrument to evaluate the impact of providing informal care for people with dementia.

Obtaining EQ-5D-5L utilities from the disease specific quality of life Alzheimer's disease scale: development and results from a mapping study.

PURPOSE: The Quality of Life Alzheimer's Disease Scale (QoL-AD) is commonly used to assess disease specific health-related quality of life (HRQoL) as rated by patients and their carers. For cost-effectiveness analyses, utilities based on the EQ-5D are often required. We report a new mapping algorithm to obtain EQ-5D indices when only QoL-AD data are available. METHODS: Different statistical models to estimate utility directly, or responses to individual EQ-5D questions (response mapping) from QoL-AD, were trialled for patient-rated and proxy-rated questionnaires. Model performance was assessed by root mean square error and mean absolute error. RESULTS: The response model using multinomial regression including age and sex, performed best in both the estimation dataset and an independent dataset. CONCLUSIONS: The recommended mapping algorithm allows researchers for the first time to estimate EQ-5D values from QoL-AD data, enabling cost-utility analyses using datasets where the QoL-AD but no utility measures were collected.

Is there equity in initial access to formal dementia care in Europe? The Andersen Model applied to the Actifcare cohort.

OBJECTIVES: In the current study, the Anderson model is used to determine equitable access to dementia care in Europe. Predisposing, enabling, and need variables were investigated to find out whether there is equitable access to dementia-specific formal care services. Results can identify which specific factors should be a target to improve access. METHODS: A total of 451 People with middle-stage dementia and their informal carers from eight European countries were included. At baseline, there was no use of formal care yet, but people were expected to start using formal care within the next year. Logistic regressions were carried out with one of four clusters of service use as dependent variables (home social care, home personal care, day care, admission). The independent variables (predisposing, enabling, and need variables) were added to the regression in blocks. RESULTS: The most significant predictors for the different care clusters are disease severity, a higher sum of (un)met needs, hours spent on informal care, living alone, age, region of residence, and gender. CONCLUSION: The Andersen model provided for this cohort the insight that (besides need factors) the predisposing variables region of residence, gender, and age do play a role in finding access to care. In addition, it showed us that the numbers of hours spent on informal care, living alone, needs, and disease severity are also important predictors within the model's framework. Health care professionals should pay attention to these predisposing factors to ensure that they do not become barriers for those in need for care.

A validation study of the ICECAP-O in informal carers of people with dementia from eight European Countries.

PURPOSE: The pressure on healthcare budgets remains high, partially due to the ageing population. Economic evaluation can be a helpful tool to inform resource allocation in publicly financed systems. Such evaluations frequently use health-related outcome measures. However, in areas such as care of older people, improving health outcomes is not necessarily the main focus of care interventions and broader outcome measures, including outcomes for those providing informal care, may be preferred when evaluating such interventions. This paper validates a recently introduced well-being measure, the ICECAP-O, in a population of informal carers for people with dementia from eight European countries. METHODS: Convergent and discriminant validity tests were performed to validate the ICECAP-O using data obtained in a sample of 451 respondents from Germany, Ireland, Italy, the Netherlands, Norway, Portugal, Sweden and the UK. These respondents completed a number of standardized questionnaires within the framework of the Actifcare project. RESULTS: The ICECAP-O performed well among informal carers, in terms of both convergent and discriminant validity. In the multivariate analysis, it was found to be significantly associated with the age of the person with dementia, EQ-5D-5L health problem index of the person with dementia, carer-patient relationship, care recipient CDR, carer LSNS Score, the PAI score, and Perseverance Time. CONCLUSION: The ICECAP-O appears to be a valid measure of well-being in informal carers for people with dementia. The ICECAP-O may therefore be useful as an outcome measure in economic evaluations of interventions aimed at such informal carers, when these aim to improve well-being beyond health.

Do caregiver profiles predict the use of dementia care services? Findings from the Actifcare study.

Objectives: Previously developed dementia caregiver profiles defined by caregiver age and burden, have been associated with caregiver quality of life, depression and perseverance time. The current aim was to investigate whether these caregiver profiles could predict subsequent service use. In addition, non-personal (e.g. meals on wheels) and supportive services (e.g. Alzheimer café) in early dementia were investigated as predictors.Methods: A total of 451 dyads of people with dementia and their informal caregivers from eight European countries were followed for one year. People were included if they did not use formal (personal) care but were expected to do so within 1 year. Logistic regression analyses were used with four clusters of service use as dependent variables (home social care, home personal care, day care and admission). The independent variables were caregiver profiles, and non-personal and supportive services at baseline.Results: Caregiver profiles were significant predictors of service use; those experiencing high strain were more likely to use formal care. The use of low-intensity, less intrusive services at baseline significantly predicted the use of home personal care and admission at follow-up. The use of day care at follow-up was predicted by the baseline use of supportive services.Conclusion: Caregiver profiles are valuable predictors for service use: this knowledge can aid professionals in ensuring optimal access to services, which is important for maintaining independence at home. In addition, the use of supportive and less intrusive, non-personal services in the early stages of dementia is to be advised.

Controlling for selective dropout in longitudinal dementia data: Application to the SveDem registry.

INTRODUCTION: Loss to follow-up in dementia studies is common and related to cognition, which worsens over time. We aimed to (1) describe dropout and missing cognitive data in the Swedish dementia registry, SveDem; (2) identify factors associated with dropout; and (3) estimate propensity scores and use them to adjust for dropout. METHODS: Longitudinal cognitive data were obtained from 53,880 persons from the SveDem national quality dementia registry. Inverse probability of censoring weights (IPCWs) were estimated using a logistic regression model on dropout. RESULTS: The mean annualized rate of change in Mini-Mental State Examination (MMSE) in those with a low MMSE (0 to 10) was likely underestimated in the complete case analysis (+1.5 points/year) versus the IPCW analysis (-0.3 points/year). DISCUSSION: Handling dropout by IPCWs resulted in plausible estimates of cognitive decline. This method is likely of value to adjust for biased dropout in longitudinal cohorts of dementia.

Challenges and recommendations for the health-economic evaluation of primary prevention programmes for dementia.

OBJECTIVE: We aimed to review health-economic evaluations of (hypothetical) intervention programmes for the primary prevention of dementia, and highlight challenges and provide recommendations for future research to estimate its cost-effectiveness. METHODS: We searched the databases PubMed, MODEM, CEA and NHS for publications on the cost-consequence, -effectiveness, -utility or -benefit analysis of (hypothetical) interventions to reduce the risk of developing dementia for persons without dementia, and described the study characteristics. RESULTS: Three publications described the evaluation of a hypothetical risk reduction due to physical activity or a multidomain intervention programme. Two studies reported a reduction of care costs. One study yielded two scenarios of increased care costs and one scenario of reduced care costs. Only one study reported the impact in QALY terms, and found a QALY gain. CONCLUSION: A few studies have evaluated a hypothetical multidomain prevention intervention, and reported that primary dementia prevention is potentially cost-saving or cost-effective. Various challenges remain to evaluate the health-economic impact of prevention interventions, including extrapolation of short-term trial effects, care costs in the dementia-free and life years gained, and accurate representation of usual care. We recommend extensive sensitivity analyses to examine the impact of assumptions regarding these aspects on the outcomes of cost-effectiveness studies.

Assessing cost-effectiveness of early intervention in Alzheimer's disease: An open-source modeling framework.

INTRODUCTION: We develop a framework to model disease progression across Alzheimer's disease (AD) and to assess the cost-effectiveness of future disease-modifying therapies (DMTs) for people with mild cognitive impairment (MCI) due to AD. METHODS: Using data from the US National Alzheimer's Coordinating Center, we apply survival analysis to estimate transition from predementia to AD dementia and ordered probit regression to estimate transitions across AD dementia stages. We investigate the cost-effectiveness of a hypothetical treatment scenario for people in MCI due to AD. RESULTS: We present an open-access model-based decision-analytic framework. Assuming a modest DMT treatment effect in MCI, we predict extended life expectancy and a reduction in time with AD dementia. DISCUSSION: Any future DMT for AD is expected to pose significant economic challenges across all health-care systems, and decision-analytic modeling will be required to assess costs and outcomes. Further developments are needed to inform these health policy considerations.

Duration of preclinical, prodromal, and dementia stages of Alzheimer's disease in relation to age, sex, and APOE genotype.

INTRODUCTION: We estimated the age-specific duration of the preclinical, prodromal, and dementia stages of Alzheimer's disease (AD) and the influence of sex, setting, apolipoprotein E (APOE) genotype, and cerebrospinal fluid tau on disease duration. METHODS: We performed multistate modeling in a combined sample of 6 cohorts (n = 3268) with death as the end stage and estimated the preclinical, prodromal, and dementia stage duration. RESULTS: The overall AD duration varied between 24 years (age 60) and 15 years (age 80). For individuals presenting with preclinical AD, age 70, the estimated preclinical AD duration was 10 years, prodromal AD 4 years, and dementia 6 years. Male sex, clinical setting, APOE ε4 allele carriership, and abnormal cerebrospinal fluid tau were associated with a shorter duration, and these effects depended on disease stage. DISCUSSION: Estimates of AD disease duration become more accurate if age, sex, setting, APOE, and cerebrospinal fluid tau are taken into account. This will be relevant for clinical practice and trial design.

Needs and quality of life of people with middle-stage dementia and their family carers from the European Actifcare study. When informal care alone may not suffice.

OBJECTIVE: The Actifcare (Access to timely formal care) study investigated needs of people with dementia and their families during the phase in which formal care is being considered, and examined whether higher need levels are related to lower quality of life (QOL). METHOD: From eight European countries 451 people with dementia and their carers participated. Needs were measured with the Camberwell Assessment of Need for the Elderly. QOL was measured with the QOL-AD, and carer quality of life was measured with the CarerQol. The relationship between needs and QOL was analysed with multiple regression analyses. RESULTS: Needs were expressed in the domains of psychological distress, daytime activities, company and information. People with dementia rated their unmet needs significantly lower than their carers: the mean number of self-rated unmet needs was 0.95, whereas the mean proxy ratings were 1.66. For met needs, the self-rated mean was 5.5 and was 8 when proxy-rated. The level of needs reported was negatively associated with QOL for both. CONCLUSION: The study results show that informal carers reported almost twice as many needs as people with dementia. The domains in which needs are expressed should be the primary focus for interventions to support   QOL. The perspectives of people with dementia are informative when identifying needs.