The Diagnostic and Prognostic Value of Neuropsychological Assessment in Memory Clinic Patients.

BACKGROUND: Neuropsychological testing has long been embedded in daily clinical practice at memory clinics but the added value of a complete neuropsychological assessment (NPA) to standard clinical evaluation is unknown. OBJECTIVE: To evaluate the added diagnostic and prognostic value of NPA to clinical evaluation only in memory clinic patients. METHODS: In 221 memory clinic patients of a prospective cohort study, clinical experts diagnosed clinical syndrome (subjective cognitive impairment (SCI), mild cognitive impairment (MCI), or dementia) and etiology (Alzheimer's disease (AD) or no AD), and provided a prognosis of disease course (decline or no decline) before and after results of NPA were made available. The reference standard was a panel consensus based on all clinical information at baseline and up to 2 follow-up assessments. RESULTS: With NPA data available, clinicians changed their initial syndromal diagnosis in 22% of patients, and the etiological diagnosis as well as the prognosis in 15%. This led to an increase in correctly classified cases of 18% for syndromal diagnosis, 5% for etiological diagnosis, and 1% for prognosis. NPA data resulted in the largest improvement in patients initially classified as SCI (syndrome: 93.3% (n = 14) correctly reclassified, etiology: net reclassification improvement [NRI] = 0.61, prognosis: NRI = 0.13) or MCI (syndrome: 89.3% (n = 23) correctly reclassified, etiology: NRI = 0.17, prognosis: NRI = 0.14), while there was no improvement in patients with dementia (syndrome: 100% (n = 1) correctly reclassified, etiology: NRI = -0.05, prognosis: NRI = -0.06). Overall, inclusion of NPA in the diagnostic process increased confidence in all diagnoses with 6-7%. CONCLUSION: Administration of a complete NPA after standard clinical evaluation has added value for diagnosing cognitive syndrome and its underlying etiology in patients regarded as non-demented based on the first clinical impression.

Ecological Assessment of Autonomy in Instrumental Activities of Daily Living in Dementia Patients by the Means of an Automatic Video Monitoring System.

Currently, the assessment of autonomy and functional ability involves clinical rating scales. However, scales are often limited in their ability to provide objective and sensitive information. By contrast, information and communication technologies may overcome these limitations by capturing more fully functional as well as cognitive disturbances associated with Alzheimer disease (AD). We investigated the quantitative assessment of autonomy in dementia patients based not only on gait analysis but also on the participant performance on instrumental activities of daily living (IADL) automatically recognized by a video event monitoring system (EMS). Three groups of participants (healthy controls, mild cognitive impairment, and AD patients) had to carry out a standardized scenario consisting of physical tasks (single and dual task) and several IADL such as preparing a pillbox or making a phone call while being recorded. After, video sensor data were processed by an EMS that automatically extracts kinematic parameters of the participants' gait and recognizes their carried out activities. These parameters were then used for the assessment of the participants' performance levels, here referred as autonomy. Autonomy assessment was approached as classification task using artificial intelligence methods that takes as input the parameters extracted by the EMS, here referred as behavioral profile. Activities were accurately recognized by the EMS with high precision. The most accurately recognized activities were "prepare medication" with 93% and "using phone" with 89% precision. The diagnostic group classifier obtained a precision of 73.46% when combining the analyses of physical tasks with IADL. In a further analysis, the created autonomy group classifier which obtained a precision of 83.67% when combining physical tasks and IADL. Results suggest that it is possible to quantitatively assess IADL functioning supported by an EMS and that even based on the extracted data the groups could be classified with high accuracy. This means that the use of such technologies may provide clinicians with diagnostic relevant information to improve autonomy assessment in real time decreasing observer biases.

Automatic speech analysis for the assessment of patients with predementia and Alzheimer's disease.

BACKGROUND: To evaluate the interest of using automatic speech analyses for the assessment of mild cognitive impairment (MCI) and early-stage Alzheimer's disease (AD). METHODS: Healthy elderly control (HC) subjects and patients with MCI or AD were recorded while performing several short cognitive vocal tasks. The voice recordings were processed, and the first vocal markers were extracted using speech signal processing techniques. Second, the vocal markers were tested to assess their "power" to distinguish among HC, MCI, and AD. The second step included training automatic classifiers for detecting MCI and AD, using machine learning methods and testing the detection accuracy. RESULTS: The classification accuracy of automatic audio analyses were as follows: between HCs and those with MCI, 79% ± 5%; between HCs and those with AD, 87% ± 3%; and between those with MCI and those with AD, 80% ± 5%, demonstrating its assessment utility. CONCLUSION: Automatic speech analyses could be an additional objective assessment tool for elderly with cognitive decline.

Diagnosing Alzheimer's disease: a systematic review of economic evaluations.

BACKGROUND: The objective of this study is to systematically review the literature on economic evaluations of interventions for the early diagnosis of Alzheimer's disease (AD) and related disorders and to describe their general and methodological characteristics. We focused on the diagnostic aspects of the decision models to assess the applicability of existing decision models for the evaluation of the recently revised diagnostic research criteria for AD. METHODS: PubMed and the National Institute for Health Research Economic Evaluation database were searched for English-language publications related to economic evaluations on diagnostic technologies. Trial-based economic evaluations were assessed using the Consensus on Health Economic Criteria list. Modeling studies were assessed using the framework for quality assessment of decision-analytic models. RESULTS: The search retrieved 2109 items, from which eight decision-analytic modeling studies and one trial-based economic evaluation met all eligibility criteria. CONCLUSIONS: Diversity among the study objective and characteristics was considerable and, despite considerable methodological quality, several flaws were indicated. Recommendations were focused on diagnostic aspects and the applicability of existing models for the evaluation of recently revised diagnostic research criteria for AD.

Determinants of care costs of patients with dementia or cognitive impairment.

INTRODUCTION: Dementia causes a high burden on patients, caregivers, and societies. Decision analytic models to support allocation of resources are often developed making use of cost-of-illness (COI) studies. However, current COI study estimates are highly variable due to care setting and methodological issues. We aim to explore variables explaining the variation of (formal and informal) health care costs of cognitive disorders, using a broad spectrum of variables, including patient, caregiver, and social context variables. METHODS: A bottom-up COI study design was used in which a societal viewpoint and a validated method to measure and value informal care was applied. Data were analyzed using univariate, multivariate, and forward regression analyses. RESULTS: The average 1-year health care sector costs were &OV0556;26,140 ($34,505 or £17,775) and &OV0556;11,931 ($15,749 or £8113) for patient and family. The analyses indicated that cognitive functioning, caregiver burden, patient sex, and instrumental activities of daily living were significantly associated with care costs independently. CONCLUSIONS: Cognitive functioning and instrumental activities of daily living are important variables to include in health care decision models. We recommend also including caregiver burden and patient sex in decision models for health policy decision makers to fully reflect the heterogeneity of the disease progression of cognitive disorders.

Diagnostic and economic evaluation of new biomarkers for Alzheimer's disease: the research protocol of a prospective cohort study.

BACKGROUND: New research criteria for the diagnosis of Alzheimer's disease (AD) have recently been developed to enable an early diagnosis of AD pathophysiology by relying on emerging biomarkers. To enable efficient allocation of health care resources, evidence is needed to support decision makers on the adoption of emerging biomarkers in clinical practice. The research goals are to 1) assess the diagnostic test accuracy of current clinical diagnostic work-up and emerging biomarkers in MRI, PET and CSF, 2) perform a cost-consequence analysis and 3) assess long-term cost-effectiveness by an economic model. METHODS/DESIGN: In a cohort design 241 consecutive patients suspected of having a primary neurodegenerative disease are approached in four academic memory clinics and followed for two years. Clinical data and data on quality of life, costs and emerging biomarkers are gathered.Diagnostic test accuracy is determined by relating the clinical practice and new research criteria diagnoses to a reference diagnosis. The clinical practice diagnosis at baseline is reflected by a consensus procedure among experts using clinical information only (no biomarkers). The diagnosis based on the new research criteria is reflected by decision rules that combine clinical and biomarker information. The reference diagnosis is determined by a consensus procedure among experts based on clinical information on the course of symptoms over a two-year time period.A decision analytic model is built combining available evidence from different resources among which (accuracy) results from the study, literature and expert opinion to assess long-term cost-effectiveness of the emerging biomarkers. DISCUSSION: Several other multi-centre trials study the relative value of new biomarkers for early evaluation of AD and related disorders. The uniqueness of this study is the assessment of resource utilization and quality of life to enable an economic evaluation. The study results are generalizable to a population of patients who are referred to a memory clinic due to their memory problems. TRIAL REGISTRATION: NCT01450891.

Relationship between measures of dementia severity and observation of daily life functioning as measured with the Assessment of Motor and Process Skills (AMPS).

BACKGROUND: Cognitive impairment is mostly regarded as the core symptom of dementia, but several other domains (such as daily functioning) are equally relevant to assess the severity of dementia. The relationship between these domains is unclear. The Assessment of Motor and Process Skills (AMPS) is a relatively unexplored instrument in people with dementia, measuring severity by direct observation. OBJECTIVE: To study the relationship between the AMPS and scores on several commonly used outcome measures for the assessment of dementia severity, and to examine the possible influence of neuropsychiatric symptoms on these relationships in patients with cognitive disorders. METHODS: Cross-sectional data of 118 patients with cognitive disorders were used; data on cognition (Mini-Mental State Examination, MMSE; CAMCOG), global severity (Global Deterioration Scale, GDS), daily life functioning (Instrumental Activities of Daily Living, IADL), and neuropsychiatric symptoms (Neuropsychiatric Inventory, NPI) were collected and analyzed using correlation and regression analyses. Different combinations of the severity measures were tested for their ability to predict the AMPS process ability scores. RESULTS: Scores on the MMSE, CAMCOG and GDS were moderately associated with the AMPS process ability score. These measures explained between 27 and 44% of the variance in the AMPS score. The presence of apathy influenced the association between the cognitive measures and the AMPS score. CONCLUSION: Commonly used measures of dementia severity are only moderately associated with observation of performance on daily activities. This underlines the need for direct observation of daily activities in dementia patients. This relationship between several approaches of assessing dementia severity needs further study.

Do caregiver management strategies influence patient behaviour in dementia?

OBJECTIVES: Little is known about the effectiveness of caregiver management strategies on the functioning of the demented patient. However, identification of specific caregiver strategies may provide useful information on the management and manifestation of behavioural problems in dementia. METHODS: Ninety-nine patients with dementia and their informal caregivers were followed up for one year. Interviews were used to assess differences in caregiver management strategies. Behavioural disturbances in the patient were measured with the Neuropsychiatric Inventory (NPI). Repeated measures analysis were carried out to investigate the relationship between caregiver management strategies and patient behaviour. RESULTS: Three caregiver management strategies were identified, based on whether caregivers accepted, or not, the caregiving situation and dementia related problems. Caregivers characterized by non-acceptance were typified as 'Non-adapters'; caregivers characterized by acceptance were further subdivided into two groups typified as 'Nurturers' and 'Supporters'. Caregiver characteristics such as sex, education and personality were important determinants of management strategies. MANOVA showed that non-adapters reported significantly more hyperactivity symptoms in patients and felt less competent than did supporters. CONCLUSIONS: Caregiver management strategies would appear to be associated with behavioural problems in dementia, and are important in predicting patient behaviour and caregiver burden. Intervention programmes should aim at teaching caregivers adequate management strategies.