Exploring diagnostic strategies for memory complaints in older adults: A retrospective general practice database study.

OBJECTIVES: For older people who worry about their memory, their general practitioner (GP) is often the first healthcare professional they turn to. This study aims to increase knowledge of GPs' daily practice on diagnostic strategies for patients who present themselves with memory complaints and/or worries about dementia for the first time in general practice and to explore associations of patients' characteristics with these strategies. METHOD: Retrospective observational study using electronic patient records from patients presenting with memory complaints between 2012 and 2019. The patient records are derived from a Dutch primary care registration network. The decision on diagnostic strategy was extracted and categorized as (1) wait and see, (2) diagnostic testing in primary care, or (3) referral. Patient characteristics (gender, age, general practice, level of comorbidities, chronic polypharmacy, and the number of consultations on memory complaints), fear of developing dementia, and information on why the first consultation on memory complaints was scheduled were extracted. RESULTS: A total of 228 patients were included. Most patients were cared for within primary care, either for further primary care diagnostics (56.1%) or because a wait-and-see strategy was pursued (14.9%). One-third (28.9%) of patients were referred. Differences between diagnostic strategies in patient characteristics, fear of developing dementia, or reason for first consultation between these diagnostic strategies were not found, nor were these variables predictive of referral. CONCLUSION: Most Dutch patients with memory complaints and/or worries about dementia who seek help from their GP for the first time are cared for in the primary care setting for the following 6 months. The lack of association between included patient characteristics and diagnostic strategies highlights the complexity of the decision-making process on diagnostic testing for dementia in general practice.

Why to test for dementia: perspectives of patients, significant others and general practitioners.

BACKGROUND: This study aims to provide greater insight into the current decision-making process on diagnostic testing for dementia by exploring the expectations, needs and experiences of patients with memory complaints, significant others and general practitioners (GPs). METHODS: We performed semi-structured interviews with patients (>60 years) who consulted their GP on memory complaints, significant others and GPs. Participants were recruited until data saturation was reached in thematic analysis of interview transcripts. RESULTS: We performed 51 interviews (patients n = 20, significant others n = 15, GPs n = 16). Thematic analysis revealed four themes: (i) 'drivers to (not) testing', i.e. need to act on symptoms, beliefs on the necessity and expected outcomes of diagnostic testing; (ii) 'patient preferences and context are critical in the actual decision', i.e. in the actual decision-making process interpretation of symptoms, GPs' desire to meet patient preferences, social context and healthcare system dynamics guided the decision; (iii) 'need for individualised communication in the decision-making process', i.e. for patients feeling heard was a prerequisite for decision-making and GPs tailored communication strategies to individual patients and (iv) 'GP practice and barriers to shared decision-making (SDM)', i.e. although GPs value SDM in the decision on diagnostic testing for dementia, patients express limited awareness of the decision and options at stake. CONCLUSIONS: Decision-making on diagnostic testing for dementia is a multifactorial and preference-guided process for all involved stakeholders, but decisions are often not explicitly jointly made. Development of patient decision aids could facilitate better involvement and more informed choices by patients.

Moving forward with dementia: an explorative cross-country qualitative study into post-diagnostic experiences.

OBJECTIVES: This explorative cross-country qualitative study aims to describe experiences of receiving a dementia diagnosis and experiences of support following a diagnosis in Australia, Canada, the Netherlands and Poland. METHOD: Qualitative study using projective techniques during online focus groups, online and telephone interviews with people with dementia and caregivers. RESULTS: Twenty-three people with dementia and 53 caregivers participated. Qualitative content analysis revealed five themes; (1) 'Coming to terms with dementia' helped people deal with complex emotions to move forward. (3) 'The social network as a source of support' and (4) 'The challenges and realities of formal support' and impacted 'Coming to terms with dementia'. (2) 'Navigating life with dementia as a caregiver' highlights caregiver burden and was impacted by (4) 'The challenges and realities of formal support'. People were (5) 'Self-caring and preparing for tomorrow' as they focused on maintaining current health whilst planning the future. Despite differences in healthcare and post-diagnostic support systems, there were more similarities across countries than differences. CONCLUSION: Across countries, formal support and support from friends and family are crucial for people with dementia and caregivers to come to terms with dementia and maintain carer wellbeing to ultimately live well with dementia.

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.

Experiences of people with dementia and informal caregivers with post-diagnostic support: Data from the international COGNISANCE study.

OBJECTIVES: The study aims to describe people with dementia and informal caregivers' respective experiences of support after diagnosis and compares these experiences. Additionally, we determine how people with dementia and informal caregivers who are satisfied with support differ from those dissatisfied. METHODS: A cross-sectional survey study in Australia, Canada, the Netherlands, Poland, and United Kingdom was carried out to examine people with dementia and informal caregivers experience with support (satisfaction with information, access to care, health literacy, and confidence in ability to live well with dementia). The separate surveys contained closed questions. Analysis consisted of descriptive statistics and Chi-square tests. RESULTS: Ninety people with dementia and 300 informal caregivers participated, and 69% of people with dementia and 67% of informal caregivers said support after diagnosis helped them deal more efficiently with their concerns. Up to one-third of people with dementia and informal caregivers were dissatisfied with information about management, prognosis, and strategies for living positively. Few people with dementia (22%) and informal caregivers (35%) received a care plan. People with dementia were more often satisfied with information, had more often confidence in their ability to live well with dementia, and were less often satisfied with access to care compared to informal caregivers. Informal caregivers who were satisfied with support were more satisfied with information and access to care compared to informal caregivers not satisfied with support. CONCLUSIONS: Experience of dementia support can be improved and people with dementia and informal caregiver differ in their experiences of support.

Understanding patients' and significant others' preferences on starting a diagnostic trajectory for dementia: An integrative review.

OBJECTIVE: To explore the preferences of people with memory complaints (PwMC) and their significant others regarding starting a diagnostic trajectory for dementia. METHODS: A systematic literature search was conducted in PubMed, PsycINFO, CINAHL, Web of Science, and Embase. Selection of abstracts and papers was performed independently by two researchers. Methodological quality was assessed with the Mixed Method Appraisal Tool. Result sections of the selected papers were thematically synthesized. RESULTS: From 2497 citations, seven qualitative studies and two mixed methods studies published between 2010 and 2020 were included. Overall quality of the studies was high to moderate. A thematic synthesis showed that preferences for starting a diagnostic trajectory arose from the feeling of needing to do something about the symptoms, beliefs on the necessity and expected outcomes of starting a diagnostic trajectory. These views were influenced by normalization or validation of symptoms, the support or wishes of the social network, interactions with health care professionals, the health status of the PwMC, and societal factors such as stigma and socioeconomic status. CONCLUSION: A variety of considerations with regard to decision-making on starting a diagnostic trajectory for dementia were identified. This emphasizes the need to explore individual preferences to facilitate a timely dementia diagnosis.

Associations between unmet needs for daytime activities and company and scores on the Neuropsychiatric Inventory-Questionnaire in people with dementia: a longitudinal study.

OBJECTIVES: To examine prospectively the association between unmet needs for daytime activities and company and behavioural and psychological symptoms of dementia. METHODS: We included 451 people with mild or moderate dementia, from eight European countries, who were assessed three times over 12 months. Unmet needs were measured with the Camberwell Assessment of Need for the Elderly. Three sub-syndromes of the Neuropsychiatric Inventory-Questionnaire were regressed, one-by-one, against unmet needs for daytime activities and company, adjusting for demographic and clinical-functional covariates. RESULTS: Unmet needs for daytime activities were associated with more affective symptoms at baseline, six and twelve months, mean 0.74 (p < 0.001), 0.76 (p < 0.001) and 0.78 (p = 0.001) points higher score respectively, and with more psychotic symptoms at baseline (mean 0.39 points, p = 0.007) and at six months follow-up (mean 0.31 points, p = 0.006). Unmet needs for company were associated with more affective symptoms at baseline, six and twelve months, mean 0.44 (p = 0.033), 0.67 (p < 0.001) and 0.91 (p < 0.001) points higher score respectively, and with more psychotic symptoms at baseline (mean 0.40 points, p = 0.005) and at six months (mean 0.35 points, p = 0.002) follow-up. CONCLUSION: Interventions to reduce unmet needs for daytime activities and company could reduce affective and psychotic symptoms in people with dementia.

Development of best practice recommendations to enhance access to and use of formal community care services for people with dementia in Europe: a Delphi process conducted by the Actifcare project.

OBJECTIVES: Home-dwelling people with dementia and their informal carers experience barriers impeding access to community care services. This study is a part of the Actifcare project where eight countries participated. The aim was to achieve consensus on best practice recommendations for enhancing access to and use of formal community care services. METHOD: A Delphi consensus process was conducted. A total of 48 professional experts, 14 people with dementia and 20 informal carers rated the importance of 72 statements on a 7-point Likert scale. Consensus was based on the median and level of dispersion. RESULTS: Sixty-two statements reached consensus, resulting in three categories of recommendations. An appointed contact person was central in Recommendations to enhance access. Coordination and flexibility in setting and type of services were among the Recommendations to enhance use. Training of health care personnel and person-centred care were central Recommendations that can facilitate access or use indirectly. CONCLUSION: The Actifcare Best Practice Recommendations suggest practical measures that can be taken by decision makers to enhance access and use of community care services, and thereby enhance quality of care and quality of life for home dwelling people with dementia and their informal carers.

Determinants of Cross-Sectional and Longitudinal Health-Related Quality of Life in Memory Clinic Patients Without Dementia.

OBJECTIVE: To identify determinants within 3 different domains (ie, somatic comorbidities, cognitive functioning, and neuropsychiatric symptoms [NPS]) of health-related quality of life (HRQoL) over time in memory clinic patients without dementia. METHODS: This longitudinal multicenter cohort study with a 3-year observation period recruited 315 individuals (age: 69.8 ± 8.6, 64.4% males, Mini-Mental State Examination score 26.9 ± 2.6). A multivariable explanatory model was built using linear mixed effects models (forward selection per domain) to select determinants for self-perceived HRQoL over time, as measured by the EuroQoL-5D visual analogue scale (EQ VAS). RESULTS: Mean HRQoL at study entry was 69.4 ± 15.6. The presence of agitation, appetite and eating abnormalities, and eyes/ears/nose (ie, sensory impairment) comorbidities were associated with a change in HRQoL over time. Agitation was most strongly associated with HRQoL over time. CONCLUSIONS: The association of somatic comorbidities and NPS in memory clinic patients with course of HRQoL shows that these should receive more awareness, detection, and monitoring by clinicians.

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.

Interventions to enhance access to and utilization of formal community care services for home dwelling persons with dementia and their informal carers. A scoping review.

Objectives: Home dwelling people with dementia and their informal carers often do not receive the formal care services they need. This study examined and mapped the research regarding interventions to improve access and use of formal community care services.Method: This is a scoping review with searches in PubMed, CINAHL, PsychINFO, Medline, Cochrane Database of Systematic Reviews, Social Science Citation index and searches of grey literature in international and national databases. Studies were categorized according to the measure used to enhance access or use.Results: From international databases, 2833 studies were retrieved, 11 were included. Five studies were included from other sources. In total, 16 studies published between 1989 and 2018 were examined; seven randomized controlled trials, six pretest-posttest studies and three non-randomized controlled studies. Sample sizes varied from 29 to 2682 participants, follow-up from four weeks to four years. Five types of interventions were identified: Case management, monetary support, referral enhancing, awareness & information focused and inpatient focused. Only two studies had access or use of community services as the primary outcome. Fourteen studies, representing all five types of interventions, had positive effects on one or more relevant outcomes. Two interventions had no effect on relevant outcomes.Conclusion: The included studies varied widely regarding design, type of intervention and outcomes. Based on this, the evidence base for interventions to enhance access to and use of formal community services is judged to be limited. The most studied type of intervention was case management. More research is recommended in this field.

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.

Barriers and facilitators to the access to and use of formal dementia care: findings of a focus group study with people with dementia, informal carers and health and social care professionals in eight European countries.

BACKGROUND: People with dementia and informal carers often access formal care late in the process of dementia. The barriers and facilitators to service use from the perspectives of different stakeholders involved are not well understood. Thus, we aimed to explore the barriers and facilitators of access to and utilisation of formal care from the perspectives of people with dementia, their informal carers and health and social care professionals. METHOD: Focus groups with people with dementia, informal carers and professionals were conducted in eight European countries. Recruitment targeted people with dementia, informal carers with experience of formal care and professionals involved in providing (access to) formal care. Qualitative content analysis using open coding was used on a national level. Cross-national synthesis was based on the translated national reports. RESULTS: Overall, 55 focus groups with 261 participants were conducted, involving 51 people with dementia, 96 informal carers and 114 professionals. Sixteen categories describing barriers and facilitators were identified, referring to three global themes: Aspects related to 1) individuals involved, 2) the system or 3) overarching aspects. The attitudes and beliefs of people with dementia and their carers may have a major impact, and they often serve as barriers. Formal care was perceived as a threat to the individual independence of people with dementia and was thus avoided as long as possible. A healthcare professional serving as a constant key contact person could be an essential facilitator to overcome these barriers. Contact should be initiated proactively, as early as possible, and a trusting and consistent relationship needs to be established. Beyond that, the findings largely confirm former research and show that barriers to accessing and using formal care still exist across Europe despite a number of national and European initiatives. CONCLUSION: Further investigations are needed to elaborate how the concept of a key contact person could be integrated with existing case management approaches and how the independence and autonomy of people with dementia can be strengthened when formal care needs to be accessed and used. These may be meaningful facilitators regarding enhanced access to formal care for people with dementia and their families.

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.

Perspectives of policy and political decision makers on access to formal dementia care: expert interviews in eight European countries.

BACKGROUND: As part of the ActifCare (ACcess to Timely Formal Care) project, we conducted expert interviews in eight European countries with policy and political decision makers, or representatives of relevant institutions, to determine their perspectives on access to formal care for people with dementia and their carers. METHODS: Each ActifCare country (Germany, Ireland, Italy, The Netherlands, Norway, Portugal, Sweden, United Kingdom) conducted semi-structured interviews with 4-7 experts (total N = 38). The interview guide addressed the topics "Complexity and Continuity of Care", "Formal Services", and "Public Awareness". Country-specific analysis of interview transcripts used an inductive qualitative content analysis. Cross-national synthesis focused on similarities in themes across the ActifCare countries. RESULTS: The analysis revealed ten common themes and two additional sub-themes across countries. Among others, the experts highlighted the need for a coordinating role and the necessity of information to address issues of complexity and continuity of care, demanded person-centred, tailored, and multidisciplinary formal services, and referred to education, mass media and campaigns as means to raise public awareness. CONCLUSIONS: Policy and political decision makers appear well acquainted with current discussions among both researchers and practitioners of possible approaches to improve access to dementia care. Experts described pragmatic, realistic strategies to influence dementia care. Suggested innovations concerned how to achieve improved dementia care, rather than transforming the nature of the services provided. Knowledge gained in these expert interviews may be useful to national decision makers when they consider reshaping the organisation of dementia care, and may thus help to develop best-practice strategies and recommendations.

Caregiver profiles in dementia related to quality of life, depression and perseverance time in the European Actifcare study: the importance of social health.

OBJECTIVES: To identify caregiver profiles of persons with mild to moderate dementia and to investigate differences between identified caregiver profiles, using baseline data of the international prospective cohort study Actifcare. METHODS: A latent class analysis was used to discover different caregiver profiles based on disease related characteristics of 453 persons with dementia and their 453 informal caregivers. These profiles were compared with regard to quality of life (CarerQoL score), depressive symptoms (HADS-D score) and perseverance time. RESULTS: A 5-class model was identified, with the best Bayesian Information Criterion value, significant likelihood ratio test (p < 0.001), high entropy score (0.88) and substantive interpretability. The classes could be differentiated on two axes: (i) caregivers' age, relationship with persons with dementia, severity of dementia, and (ii) tendency towards stress and difficulty adapting to stress. Classes showed significant differences with all dependent variables, and were labelled 'older low strain', 'older intermediate strain', 'older high strain', 'younger low strain' and 'younger high strain'. CONCLUSION: Differences exist between types of caregivers that explain variability in quality of life, depressive symptoms and perseverance time. Our findings may give direction for tailored interventions for caregivers of persons with dementia, which may improve social health and reduce health care costs.

Access to timely formal dementia care in Europe: protocol of the Actifcare (ACcess to Timely Formal Care) study.

BACKGROUND: Previous findings indicate that people with dementia and their informal carers experience difficulties accessing and using formal care services due to a mismatch between needs and service use. This mismatch causes overall dissatisfaction and is a waste of the scarce financial care resources. This article presents the background and methods of the Actifcare (ACcess to Timely Formal Care) project. This is a European study aiming at best-practice development in finding timely access to formal care for community-dwelling people with dementia and their informal carers. There are five main objectives: 1) Explore predisposing and enabling factors associated with the use of formal care, 2) Explore the association between the use of formal care, needs and quality of life and 3) Compare these across European countries, 4) Understand the costs and consequences of formal care services utilization in people with unmet needs, 5) Determine the major costs and quality of life drivers and their relationship with formal care services across European countries. METHODS: In a longitudinal cohort study conducted in eight European countries approximately 450 people with dementia and informal carers will be assessed three times in 1 year (baseline, 6 and 12 months). In this year we will closely monitor the process of finding access to formal care. Data on service use, quality of life and needs will be collected. DISCUSSION: The results of Actifcare are expected to reveal best-practices in organizing formal care. Knowledge about enabling and predisposing factors regarding access to care services, as well as its costs and consequences, can advance the state of the art in health systems research into pathways to dementia care, in order to benefit people with dementia and their informal carers.

Qualitative study on needs and wishes of early-stage dementia caregivers: the paradox between needing and accepting help.

BACKGROUND: Early individualized interventions for informal dementia caregivers can prevent overburdening in the later stages. However, the needs of early-stage dementia caregivers (EDC) remain largely unknown. This study aimed to explore the needs and wishes and need for care of EDC to maximize the benefit of potential programs for EDC and tailor interventions accordingly. METHODS: Four focus group interviews with 28 informal caregivers of people with dementia (PwD) were analyzed using inductive content analysis. Both EDC and caregivers in the later stages were included to compare perceived EDC needs from different points in the caregiver career. RESULTS: Four themes were identified: the early-stage needs paradox, barriers in acceptance, facilitators in acceptance, and a transition from loss to adaptation. The retrospective view provided by later-stage caregivers differed from the view of EDC; EDC struggled with acknowledging needs due to fear of stigma and low acceptance. EDC stressed the importance of acceptance as a prerequisite for adequate adaptation, but were hindered by lack of knowledge, difficulty acknowledging changes, and focus on loss. In contrast, better understanding of the disease, increasing personal time, structuring ones day, and using appropriate humor can reduce negative communication, increase positive encounters and caregiver-confidence, contributing to positive interaction with the care recipient and an increase in well-being. CONCLUSIONS: Early therapeutic interventions could help caregivers identify their needs, increase knowledge about changes in roles and relationship reciprocity, and focus on enhancement of the positive, intact experiences to prevent caregiver burden.

Early cost-utility analysis of general and cerebrospinal fluid-specific Alzheimer's disease biomarkers for hypothetical disease-modifying treatment decision in mild cognitive impairment.

INTRODUCTION: The study aimed to determine the room for improvement of a perfect cerebrospinal fluid (CSF) biomarker and the societal incremental net monetary benefit of CSF in subjects with mild cognitive impairment (MCI) assuming a hypothetical disease-modifying Alzheimer's disease (AD) treatment. METHODS: A decision model compared current practice to a perfect biomarker and to two strategies positioning CSF as add-on test when current practice concluded the presence or absence of AD. RESULTS: The simulated MCI population was aged on average 68.3 and 49% had AD. The room for improvement by the perfect CSF test was 0.39 quality adjusted life years, €33,622 ($43,372) savings, 2.0 potential beneficial treatment years, and 1.3-year delay in dementia conversion. DISCUSSION: The results indicated more potential benefit from a biomarker positioned to verify subjects who are not expected to have AD (i.e., to prevent undertreatment) rather than to verify subjects expected to have AD (prevent overtreatment). Sensitivity analyses explored different CSF positions.

Optimizing the use of expert panel reference diagnoses in diagnostic studies of multidimensional syndromes.

BACKGROUND: In the absence of a gold standard, a panel of experts can be invited to assign a reference diagnosis for use in research. Available literature offers limited guidance on assembling and working with an expert panel for this purpose. We aimed to develop a protocol for an expert panel consensus diagnosis and evaluated its applicability in a pilot project. METHODS: An adjusted Delphi method was used, which started with the assessment of clinical vignettes by 3 experts individually, followed by a consensus discussion meeting to solve diagnostic discrepancies. A panel facilitator ensured that all experts were able to express their views, and encouraged the use of argumentation to arrive at a specific diagnosis, until consensus was reached by all experts. Eleven vignettes of patients suspected of having a primary neurodegenerative disease were presented to the experts. Clinical information was provided stepwise and included medical history, neurological, physical and cognitive function, brain MRI scan, and follow-up assessments over 2 years. After the consensus discussion meeting, the procedure was evaluated by the experts. RESULTS: The average degree of consensus for the reference diagnosis increased from 52% after individual assessment of the vignettes to 94% after the consensus discussion meeting. Average confidence in the diagnosis after individual assessment was 85%. This did not increase after the consensus discussion meeting. The process evaluation led to several recommendations for improvement of the protocol. CONCLUSION: A protocol for attaining a reference diagnosis based on expert panel consensus was shown feasible in research practice.