Quality of life as an outcome in Alzheimer's disease and other dementias--obstacles and goals

Valuing the AD-5D Dementia Utility Instrument: An Estimation of a General Population Tariff

OBJECTIVE

This paper reports on the valuation of quality-of-life states in the Alzheimer's Disease Five Dimensions (AD-5D) instrument in a representative sample of the general population in Australia using the discrete-choice experiment with duration (DCE_TTO) elicitation technique.

METHOD

A DCE with 200 choice sets of two quality-of-life (QoL) state-duration combinations blocked into 20 survey versions, with ten choice sets in each version, was designed and administered online to a sample representative of the Australian population. Two additional choice sets comprising internal consistency and dominance checks were included in each survey version. A range of model specifications investigating preferences with respect to duration and interactions between AD-5D dimension levels were estimated. Utility weights were developed, with estimated coefficients transformed to the 0 (being dead) to 1 (full health) scale, suitable for the calculation of quality-adjusted life-year (QALY) weights for use in economic evaluation.

RESULTS

In total, 1999 respondents completed the choice experiment. Overall, respondents were slightly better educated and had higher annual incomes than the Australian general population. The estimation results from different specifications and models were broadly consistent with the monotonic nature of the AD-5D: utility increased with increased life expectancy and decreased as the severity level for each dimension worsened. A utility value set was generated for the calculation of utilities for all QoL states defined by the AD-5D descriptive system.

CONCLUSION

The DCE-based utility value set is now available to use to generate QALYs for the economic evaluation of treatments and interventions targeting people with dementia and/or their family caregivers.

A qualitative exploration of the content and face validity of preference-based measures within the context of dementia

BACKGROUND

Assessing the cost-effectiveness of interventions for people with dementia, based on cost per quality-adjusted life years (QALYs) gained, requires that the measures used to derive QALYs are preference-based whilst also being valid, feasible to use, comprehensible and acceptable for people with dementia. The aim of this study was to assess the content and face validity of six preference-based measures (PBMs) within the context of dementia.

METHODS

Qualitative focus groups and interviews were conducted with community-dwelling individuals with mild dementia and carers of people with dementia. After exploring participants' understanding of 'quality of life' (QoL), six PBMs were assessed for content and face validity: two measures assessing health-related QoL (EQ-5D-5L and AQoL-8D); two covering broader aspects of capability wellbeing and social care-related QoL (ICECAP-O and ASCOT); and two dementia-specific QoL measures (DEMQOL-U and AD-5D). A random mix of one health-related QoL measure, one wellbeing measure, and one dementia-specific measure was explored in each session. All sessions were audiotaped and transcribed verbatim. Data were analysed thematically.

RESULTS

Nine individuals with mild dementia and 17 carers of people with dementia participated across 4 focus groups and 10 interviews. Participants perceived 9 broad QoL domains as relevant to them: Activity, Autonomy, Cognition, Communication, Coping, Emotions, End-of-Life, Physical Functioning, and Relationships. These domains had limited overlap with the content of the six PBMs. Assessment of face validity was summarized into eight themes: (1) ambiguous questions, (2) double -barrelled questions, (3) difficult/abstract questions, (4) judgemental/confronting questions, (5) lack of relevance and comprehensiveness, (6) response options, (7) layout/format and (8) proxy-response. There was no clear preference for one of the six measures explored; participants identified advantages and disadvantages across all measures. Although particularly designed for individuals with dementia, dementia-specific QoL measures were not always favoured over non-specific measures.

CONCLUSION

Given the shortcomings of PBMs identified in this study, further empirical comparative analyses are necessary to guide the selection of PBMs for future dementia research.

Traditional Oriental Medicines and Alzheimer's Disease

Alzheimer’s disease (AD), which is the most major cause of dementia, is a progressive neurodegenerative disease that affects cognitive functions. Even though the prevalence of AD is continuously increasing, few drugs including cholinesterase inhibitors and N-methyl D-aspartate-receptor antagonists were approved to treat AD. Because the clinical trials of AD drugs with single targets, such as β-amyloid and tau, have failed, the development of multi-target drugs that ameliorate many of the symptoms of AD is needed. Thus, recent studies have investigated the effects and underlying mechanisms of herbal formulae consisting of various herb combinations used to treat AD. This review discusses the results of clinical and nonclinical studies of the therapeutic efficacy in AD and underlying mechanisms of the herbal formulae of traditional Oriental medicines and bioactive compounds of medicinal plants.

The conceptual relevance of assessment measures in patients with mild/mild-moderate Alzheimer's disease

Introduction

This study aims to evaluate the conceptual relevance of four measures of disease activity in patients with mild/mild-moderate Alzheimer's disease (AD): (1) the Alzheimer's Disease Assessment Scale–Cognitive Subscale; (2) the Alzheimer's Disease Cooperative Study–Activities of Daily Living Inventory; (3) the Neuropsychiatry Inventory; and (4) the Dependence Scale.

Methods

A conceptual model depicting patient experience of mild AD was developed via literature review; concepts were compared with the items of the four measures. Relevance of the concepts included in the four measures was evaluated by patients with mild AD in a survey and follow-up interviews.

Results

The four measures assessed few of the symptoms/impacts of mild AD identified within the literature. Measured items addressing emotional impacts were deemed most relevant by participants but were included in the measures only superficially.

Discussion

The four assessment measures do not appear to capture the concepts most relevant to/important to patients with mild/mild-moderate AD.

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Many impacts associated with mild Alzheimer's disease were reported by patients.

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The included outcome measures assessed did not provide high conceptual coverage.

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These four measures appeared more suitable for more severe Alzheimer's disease.

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Completion of patient reported outcomes should be possible in this patient population.

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These may be currently used in addition to clinician- and observer-reported outcomes.

A Survey of Patient and Partner Outcome and Treatment Preferences in Mild Cognitive Impairment

BACKGROUND

The patient-centered movement in health care is increasing efforts to design studies and interventions that address the outcomes that matter most to patients and their families. Research has not adequately addressed Alzheimer's disease patient and caregiver preferences.

OBJECTIVE

To survey the outcome and treatment preferences of patients and caregivers who had completed a multicomponent behavioral intervention for mild cognitive impairment (MCI).

METHODS

Extending prior work, we conducted an online survey regarding outcome and intervention preferences. Participants were patients with MCI and partners who completed the HABIT Healthy Action to Benefit Independence & Thinking ® program.

RESULTS

Both patient and partner respondents ranked patient quality of life as the highest priority, followed by patient self-efficacy, functional status, patient mood, and patient memory performance. Distressing behaviors and caregiver outcomes (burden, mood, and self-efficacy) had low rankings. Regarding the importance of HABIT ® program components, memory compensation training was ranked highest and wellness education lowest by all groups.

CONCLUSION

Additional research should compare patient preference for patient reported outcomes, traditional neuropsychological and clinician outcomes, and modern biomarker outcomes.

Developing a dementia-specific health state classification system for a new preference-based instrument AD-5D

Background

With an ageing population, the number of people with dementia is rising. The economic impact on the health care system is considerable and new treatment methods and approaches to dementia care must be cost effective. Economic evaluation requires valid patient reported outcome measures, and this study aims to develop a dementia-specific health state classification system based on the Quality of Life for Alzheimer’s disease (QOL-AD) instrument (nursing home version). This classification system will subsequently be valued to generate a preference-based measure for use in the economic evaluation of interventions for people with dementia.

Methods

We assessed the dimensionality of the QOL-AD to develop a new classification system. This was done using exploratory and confirmatory factor analysis and further assessment of the structure of the measure to ensure coverage of the key areas of quality of life. Secondly, we used Rasch analysis to test the psychometric performance of the items, and select item(s) to describe each dimension. This was done on 13 items of the QOL-AD (excluding two general health items) using a sample of 284 residents living in long-term care facilities in Australia who had a diagnosis of dementia.

Results

A five dimension classification system is proposed resulting from the three factor structure (defined as ‘interpersonal environment’, ‘physical health’ and ‘self-functioning’) derived from the factor analysis and two factors (‘memory’ and ‘mood’) from the accompanying review. For the first three dimensions, Rasch analysis selected three questions of the QOL-AD (‘living situation’, ‘physical health’, and ‘do fun things’) with memory and mood questions representing their own dimensions. The resulting classification system (AD-5D) includes many of the health-related quality of life dimensions considered important to people with dementia, including mood, global function and skill in daily living.

Conclusions

The development of the AD-5D classification system is an important step in the future application of the widely used QOL-AD in economic evaluations. Future valuation studies will enable this tool to be used to calculate quality adjusted life years to evaluate treatments and interventions for people diagnosed with mild to moderate dementia.

Priority of Treatment Outcomes for Caregivers and Patients with Mild Cognitive Impairment: Preliminary Analyses

INTRODUCTION

The patient-centered movement advocates for greater attention to the outcomes that matter most to patients and their families. In neurodegenerative disease, determination of patient and caregiver priorities has received scant attention in part because dementia patients are deemed unreliable reporters. However, people with mild cognitive impairment (MCI) likely retain capacity to report their preferences.

METHODS

In two separate MCI cohorts, we conducted preliminary analyses of patient and caregiver priorities among seven patient and five caregiver outcomes of the HABIT^® Healthy Action to Benefit Independence & Thinking program (Mayo Clinic, Rochester, MN, USA).

RESULTS

Via interview and paper-and-pencil reporting both patient and caregiver respondents' ranked patient and caregiver quality of life and patient self-efficacy as highest priorities, ranking them ahead of patient and caregiver mood, patient functional status, patient distressing behaviors and caregiver burden. Patients and caregivers tended to value the outcomes for their loved ones higher than their own outcomes.

CONCLUSION

Caregivers appeared to be reasonable, but not perfect, proxies for patient reports. Additional research with larger cohorts and a more comprehensive range of outcomes is needed.

A Simple and Practical Index to Measure Dementia-Related Quality of Life

BACKGROUND

Research on new treatments for dementia is gaining pace worldwide in an effort to alleviate this growing health care problem. The optimal evaluation of such interventions, however, calls for a practical and credible patient-reported outcome measure.

OBJECTIVES

To describe the refinement of the Dementia Quality-of-life Instrument (DQI) and present its revised version.

METHODS

A prototype of the DQI was adapted to cover a broader range of health-related quality of life (HRQOL) and to improve consistency in the descriptions of its domains. A valuation study was then conducted to assign meaningful numbers to all DQI health states. Pairs of DQI states were presented to a sample of professionals working with people with dementia and a representative sample of the Dutch population. They had to repeatedly select the best DQI state, and their responses were statistically modeled to obtain values for each health state.

RESULTS

In total, 207 professionals working with people with dementia and 631 members of the general population completed the paired comparison tasks. Statistically significant differences between the two samples were found for the domains of social functioning, mood, and memory. Severe problems with physical health and severe memory problems were deemed most important by the general population. In contrast, severe mood problems were considered most important by professionals working with people with dementia.

DISCUSSION

The DQI is a simple and feasible measurement instrument that expresses the overall HRQOL of people suffering from dementia in a single meaningful number. Current results suggest that revisiting the discussion of using values from the general population might be warranted in the dementia context.

Transitions between care settings in dementia: are they relevant in economic terms?

OBJECTIVES

This study was performed to assess the economic effect of interventions affecting transitions between dementia care settings in Germany.

METHODS

A Markov-model that models the course of dementia with respect to typical care setting transitions was derived. Model data and parameters were retrieved by literature reviews. A deterministic and probabilistic sensitivity analysis was conducted to account for parameter uncertainty.

RESULTS

In the base case, the expected present value of remaining lifetime costs is €25,326 for each cohort member. As a function of effectiveness, pharmaceutical interventions may reduce the costs by 2% to 13% and psychosocial interventions come with savings of 1% to 10%. A structural intervention-promoting group living as a substitute for nursing home care increases costs by 2% to 8%. Sensitivity analyses indicate high variance and variability of results, as well as valuation of informal care being a crucial parameter.

CONCLUSIONS

There are economic benefits of delayed transitions to institutional settings, especially from the viewpoint of statutory care insurances, but these do unlikely exceed intervention costs. Thus, further intervention effects should be considered. Ultimately, concentrating research on preventive and protective factors of dementia could lead to an efficient intervention from every perspective.

Dialogue on Ideal End-of-Life Care for Those With Dementia

PURPOSE

To identify both meanings and perceptions of delivery of end-of-life (EoL) care for the person experiencing dementia.

DESIGN/METHODS

As part of a larger cross-sectional mixed methods study examining quality of life in dementia, perspectives of EoL care were sought from 136 seniors using open-ended questions administered at interview.

RESULTS

Seniors living in various settings identified obligatory requisites of care as time when the finality of death needed to be accepted, comfort was prioritized, family presence was valued, appearance remained important, and solitude or time "to be with God" was stressed. Skilled nursing care, honesty, and engaged family were also necessary.

IMPLICATIONS

Understanding EoL preferences of those with dementia is critical for advocacy and service delivery.

Health-related quality of life in the Cambridge City over-75s Cohort (CC75C): development of a dementia-specific scale and descriptive analyses

BACKGROUND

The assessment of Health Related Quality of Life (HRQL) is important in people with dementia as it could influence their care and support plan. Many studies on dementia do not specifically set out to measure dementia-specific HRQL but do include related items. The aim of this study is to explore the distribution of HRQL by functional and socio-demographic variables in a population-based setting.

METHODS

Domains of DEMQOL's conceptual framework were mapped in the Cambridge City over 75's Cohort (CC75C) Study. HRQL was estimated in 110 participants aged 80+ years with a confirmed diagnosis of dementia with mild/moderate severity. Acceptability (missing values and normality of the total score), internal consistency (Cronbach's alpha), convergent, discriminant and known group differences validity (Spearman correlations, Wilcoxon Mann-Whitney and Kruskal-Wallis tests) were assessed. The distribution of HRQL by socio-demographic and functional descriptors was explored.

RESULTS

The HRQL score ranged from 0 to 16 and showed an internal consistency Alpha of 0.74. Validity of the instrument was found to be acceptable. Men had higher HRQL than women. Marital status had a greater effect on HRQL for men than it did for women. The HRQL of those with good self-reported health was higher than those with fair/poor self-reported health. HRQL was not associated with dementia severity.

CONCLUSIONS

To our knowledge this is the first study to examine the distribution of dementia-specific HRQL in a population sample of the very old. We have mapped an existing conceptual framework of dementia specific HRQL onto an existing study and demonstrated the feasibility of this approach. Findings in this study suggest that whereas there is big emphasis in dementia severity, characteristics such as gender should be taken into account when assessing and implementing programmes to improve HRQL.

Health utility scores in Alzheimer's disease: differences based on calculation with American and Canadian preference weights

OBJECTIVE

Health utility scores quantify health-related quality-of-life (HRQOL) in Alzheimer's disease (AD). These scores are calculated by using preference weights derived from general population samples. We recruited persons with AD and their primary informal caregivers and examined differences in health utility scores calculated by using two sets of published preference weights.

METHODS

We recruited participants from nine clinics across Canada and administered the EuroQol five-dimensional (EQ-5D) questionnaire HRQOL instrument. We converted participants' EQ-5D questionnaire responses into two sets of health utility scores by using US and Canadian preference weights. We assessed agreement between sets by using the intraclass correlation coefficient. Bland-Altman plots depicted individual-level differences between sets.

RESULTS

For 216 persons with AD and their caregivers, mean health utility scores were higher when calculated with US instead of Canadian preference weights (P < 0.0001). The intraclass correlation coefficient (95% CI) was 0.79 (0.05-0.93) in the persons with AD group and 0.83 (0.30-0.94) in the caregiver group. Ninety-five percent of the individual differences in utility score fell between -0.16 and 0.03 for persons with AD and -0.15 and 0.05 for caregivers. Forty-three percent of these differences exceeded a minimum clinically important threshold of 0.074.

CONCLUSIONS

In AD studies, researchers should calculate health utility scores by using preference weights obtained in the general population of their country of interest. Using weights from other countries' populations could bias the utilities and adversely affect the results of economic evaluations of AD treatments.

The clinical use of quality-of-life scales in neurological disorders

Objective

Quality of life (QoL) is a growing issue in medicine, particularly in the evaluation of rehabilitative care. The concept of QoL is included in and expands the definition of health given by the WHO (World Health Organization) and comprises complete physical, mental, and social well-being. It expresses the degree of satisfaction in various areas as a result of the opportunities that arise during one's lifetime despite the restrictions and impediments that life itself puts forth. The last decade has exponentially increased the number of studies on QoL, although they are still limited.

Methods

We performed a literature review on the QoL scales used in patients with neurological disorders.

Results

Recent studies have shown the importance of QoL assessment because standard treatments do not assess the treatment impact felt by the patient. In fact, by understanding the impact of treatment on survival and QoL, one can make a clearer interpretation of the health of the patient.

Conclusion

This review has adopted an innovative holistic methodological approach, which allowed a global evaluation of the comfort reported by the patients. The scales applied in this study allowed to choose the most suitable therapeutic strategies and programme individual therapeutic treatment.

Validation study of the prototype of a disease-specific index measure for health-related quality of life in dementia

BACKGROUND

Index measures for health-related quality of life (HRQoL) quantify the desirability (utility) of a certain health state. The commonly used generic index measure, e.g. EuroQol: EQ-5D, may underestimate relevant areas of specific diseases, resulting in lower validity. Disease-specific index measures on the other hand combine disease-specificity and quantification of perceived quality on several health domains of a certain disease into one single figure. These instruments have been developed for several diseases, but a dementia-specific HRQoL index instrument was not yet available. Facing the increasing individual and societal burden of dementia, specific HRQoL values with metric characteristics are especially useful because they will provide vital information for health outcome research and economic evaluations.

AIMS OF THE STUDY

To develop and validate the prototype of a dementia-specific HRQoL index measure: Dementia Quality of life Instrument (DQI), as the first step towards valuation of the dementia health state.

METHODS

For development of the DQI we created a conceptual framework based on a review of the literature, qualitative interviews with people with dementia and their carers, expert opinion and team discussion. To assess validity we undertook a survey under 241 dementia professionals. Measurements consisted of ranking (1-5) and rating (1-10) of 5 dementia-specific DQI domains (memory, orientation, independence, social activities and mood) and simultaneously rating of 9 DQI-derived health states on a visual analogue scale (VAS). We also performed a cross-sectional study in a large sample of people with very mild to moderate dementia and their caregivers (N=145) to assess feasibility and concurrent validity. In addition, caregivers valued 10 DQI and 10 EQ-5D + C derived health states of the patient simultaneously on the same VAS.

SETTING

outpatient clinics, nursing homes and patient residences.

RESULTS

All professionals judged the selected DQI domains to be relevant. Differences in ranking and rating behaviors were small. Mood was ranked (≥ 3.3) and rated (≥ 8.2) as most, orientation as least important (rank ≤ 2.6, value 7.5) health domain for dementia. For the validation part of this study the completion rates for all domains were above 98% for patients and 100% for caregivers on patients. A priori hypothesized DQI versus QOL-AD correlations that were significant in both patients and caregivers were: memory/memory, orientation/memory, independence/physical health, social activities/energy and mood/mood. Patient/caregiver inter-rater agreement was low (K <0.2) for memory/independence, fair (K 0.2-0.4) for orientation/mood, and moderate (K 0.4-0.6) for social activities. Concurrent validity of the DQI with the EQ-5D +C was moderate. The fact that most of the correlations between the domains of these two instruments were low (≤ 0.40) showed that both instruments measure different elements of health status. As expected, modest correlations (≥ 0.40) were observed between corresponding domains of the two instruments.

CONCLUSIONS

Professionals judged all domains as relevant. The DQI prototype proved valid and feasible for patients and caregivers and is appropriate for very mild to moderate dementia. The differences in concurrent correlations with generic health status instruments imply that the dementia-specific DQI health domains indeed provide different information. The finding that patient HRQoL measured with the DQI was lower supports this notion. The new DQI shows comparable psychometric properties to the best available dementia-specific (QOL-AD) and generic (EQ-5D +C) measures. Further research is needed to generate values in the general population for each of the possible DQI states and to derive an algorithm that converts the 5 separate DQI domain scores into one single DQI Index score. Introducing the DQI Index will advance dementia-related HRQoL measurement by overcoming the shortcomings of generic and non-index instruments. This will allow more unequivocal interpretation of subjective dementia HRQoL states in dementia research.

Health state values for use in the economic evaluation of treatments for Alzheimer's disease

Alzheimer's disease (AD) is a chronic, progressive, neurodegenerative disease that places a heavy burden on people with the condition, their families and carers, health care systems and society in general. Health-related quality of life (HR-QOL) in patients deteriorates as the cognitive, behavioural and functional symptoms of AD develop. The human and financial cost of AD is forecast to grow rapidly as populations age, and those responsible for planning and financing health care face the challenge of allocating increasingly scarce resources against current and future interventions targeted towards AD. These include calls for early detection and diagnosis, preventative strategies, new medications, residential care, supportive care, and meeting the needs of carers as well as patients. Health care funders in many health systems now require a demonstration of the value of new interventions through a comparison of benefits in terms of improvements in HR-QOL and costs relative to those of competing or existing practices. Changes in HR-QOL provide the basis for the calculation of the quality-adjusted life-year (QALY), a key outcome used in economic evaluations to compare treatments within and between different disease conditions. The objective of this systematic review was to provide a summary of the published health state values (utilities) for AD patients and their carers that are currently available to estimate QALYs for use in health economic evaluations of interventions in AD. The health care literature was searched for articles published in English between 2000 and 2011, using keywords and variants including 'quality-adjusted life years', 'health state indicators', 'health utilities' and the specific names of generic measures of HR-QOL and health state valuation techniques. Databases searched included MEDLINE, EMBASE, NHS EED, PsycINFO and ISI Web of Science. This review identified 12 studies that reported utility values associated with health states in AD. Values for AD health states categorized according to cognitive impairment (where 1 = perfect health and 0 = dead) ranged from mild AD (0.52-0.73) to moderate AD (0.30-0.53) to severe AD (0.12-0.49). Utility values were almost all based on two generic measures of HR-QOL: the EQ-5D and Health Utility Index mark 2/3 (HUI2/3). There were no health state values estimated from condition- or disease-specific measures of HR-QOL. The review also identified 18 published cost-utility analyses (CUAs) of treatments for AD. The CUAs incorporated results from only three of the identified health state valuation studies. Twelve CUAs relied on the same study for health state values. We conclude that the literature on health state values in AD is limited and overly reliant on a single symptom (cognition) to describe disease progression. Other approaches to characterizing disease progression in AD based on multiple outcomes or dependency may be better predictors of costs and utilities in economic evaluations. Patient and proxy ratings were poorly correlated, particularly in patients with more advanced AD. However, proxy ratings displayed the validity and reliability across the entire range of AD severity needed to detect long-term changes relevant to economic evaluation. Further longitudinal research of patient and carer HR-QOL based on multidimensional measures of outcome and utilities is needed.

Domains and determinants of quality of life in schizophrenia and systemic lupus erythematosus

BACKGROUND

The World Health Organization Quality of Life-Bref (WHOQOL-Bref) scale was designed to measure quality of life (QOL) in both medical and psychiatric illnesses. There have been a few studies to date that compare aspects of QOL in medical and psychiatric illnesses.

AIM

The aim of the study was to compare QOL in patients with systemic lupus erythematosus (SLE), a chronic medical illness and schizophrenia, a chronic psychiatric disorder.

MATERIALS AND METHODS

In a prospective design, 50 patients with SLE and 50 patients with schizophrenia were assessed on measures of QOL by using the WHOQOL-Bref scale, demographic factors, disease severity, and psychiatric comorbidity.

RESULTS

There was a significant difference between the SLE group and the schizophrenia group on the social domain of the WHOQOL-Bref scale but not on other domains. Patients with SLE had lower scores, except on social domain. Disease severity correlated with scores on the physical domain and environmental domain in both illnesses. The presence of psychiatric comorbidity was associated with significantly lower QOL scores in SLE. The presence of insight was associated with nonsignificantly lower QOL scores in schizophrenia. There was a significant association between QOL scores and both income and religious belief system in SLE, while age and duration of illness correlated with QOL scores in schizophrenia.

CONCLUSION

Although the QOLs in schizophrenia and SLE were comparable on all domains except the social domain, the factors that mediate QOL in both these illnesses are different.

The future of Alzheimer's disease: the next 10 years

Alzheimer's disease (AD) is a fast growing world-wide epidemic. AD is a genetically complex, slowly progressive, and irreversible neurodegenerative disease of the brain. During decades of asymptomatic progression multiple interactive systems, pathways and molecular mechanisms (e.g. protein processing, aberrant signaling, inflammation and immune system, lipid transport, endocytosis, apoptosis, oxidative damage and response to stress, tau pathology, neuron and synapse loss, energy metabolism), contribute to the development of the early clinical prodromal stage with episodic memory deficits and to further decline and loss of general cognitive functioning during the final syndromal dementia stage. The non-mendelian genetically complex "sporadic" AD type is the most common form of dementia affecting people usually over the age of 65. Despite considerable progress of AD research in recent years and evolving paradigm shifts in both pathophysiological concepts as well as in diagnostic criteria fundamental challenges have not yet been resolved. The strong age-related incidence, the recent failure and complete lack of disease-modifying or preventive therapy that may delay onset or substantially affect the pathophysiology of AD, result in an enormous burden posed both on individuals, their families and care givers, and the societies at large, and these call for urgent concerted worldwide measures. Based on the meeting of the German Task Force on Alzheimer's Disease (GTF-AD) in Paris on July 19th 2011, the present position paper provides an overview on the current state and future developments in epidemiology, pathophysiology, disease conceptualization, diagnostic criteria and their use in research and clinical practice, as well as preventive and symptomatic therapeutic approaches. Particular emphasis is placed on a discussion of the different approaches to diagnostics and therapy taken by preventive/public health medicine, methodologically advanced academic research propagating the use of sophisticated biomarkers, and everyday clinical practice focusing on patient-centered care. During the next 10 years, major advances both in early detection as well as in therapy and comprehensive AD care seem mandatory. These still unmet needs call for ever more concerted and focused efforts in research across the world to combat the erupting and as yet uncontrolled epidemic of AD.

Gender-dependence of substituted judgment on quality of life in patients with dementia

BACKGROUND

Substituted judgment asks the proxy to decide what the patient would have decided, had he or she been competent. It is unclear whether substituted judgment of the patient's quality of life can serve as a surrogate measure in patients with dementia.

METHODS

212 patients with dementia and their proxies were interviewed in their homes. Dementia syndrome was characterized with cognitive, non-cognitive and functional scales. Quality of life (QoL) was assessed with the QoL-AD.

RESULTS

Substituted judgment of the patient's QoL was unrelated to dementia severity but also correlated with the proxie's own QoL (r = 0.356; p < 0.001). Gender-specific analysis reveals that for male proxies the most important variable is severity of patient's depression (r = -0.895; p = 0.001) while for female proxies it is the proxie's own QoL (r = 0.371; p < 0.001). Subjective burden correlates with the proxie's QoL in females (r = -0.282; p = 0.001) but not in males (r = -0.163, p = 0.161).

CONCLUSION

Substituted judgment of the patient's QoL does not correlate with dementia severity. Substituted judgment is subject to proxy-related variables in a gender-dependent fashion and therefore not suited to serve as an appropriate surrogate of the patients' quality of life.

Generic quality of life assessment in dementia patients: a prospective cohort study

BACKGROUND

Quality of life (QoL) is increasingly used to characterize the impact of disease and the efficacy of interventions.

METHODS

Prospective cohort study in patients' and proxies' homes with 137 patients with dementia (age 52 to 88; Mini-Mental Status Examination (MMSE) 3 to 28) and their proxies (age 43 to 90). MMSE, Behave-AD, Geriatric Depression Scale (GDS), and Bayer-ADL scale (B-ADL), and the Euroqol (EQ-5D; patient self-rating, proxy self-rating, and proxy-rating of patient).

RESULTS

B-ADL impairment and Behave-AD total score increased with dementia severity (Kruskal-Wallis p < 0.001 and p = 0.023, respectively). Patients' self-rated QoL and proxies' self-rated QoL were unrelated to dementia severity (p = 0.148 and p = 0.414, respectively). The difference between patients' self- and proxies'-rating of the patient's QoL correlated with the patient's MMSE (Spearman's rho = -0.434; p < 0.001), even if analysis was constrained to patients with mild AD (rho = -0.328; p = 0.019). The proxies' rating of the patients QoL was not only correlated with cognitive and behavioral symptoms of the patient but also with mood (GDS-score; rho = 0.317; p < 0.001) and cognitive abilities (verbal fluency; rho = 0.209; p < 0.018) of the proxy.

CONCLUSION

Proxies' assessment of the patients' QoL is related to the proxies' health, and the difference of patient's and proxie's QoL-rating is correlated with dementia severity even in mild dementia stages. QOL measures use ratings of the individual to assess the impact of symptoms and disorders on everyday life. In dementia patients, however, this impact is not captured since patients' and proxies' self-assessment of their own QoL do not reflect severity of disease whatsoever. Patients' and proxies' influencing variables render the score obtained with generic quality of life assessment meaningless in capturing the impact of dementia. Decisions on initiation or discontinuation of treatment or allocation of other resources for patients with dementia therefore need not depend on generic assessment of quality of life.