Cohort studies: a link between biomedical and care research

Transcription

1 Versorgungsforschung g g für demenziell erkrankte Menschen Health Services Research for People with Dementia Symposium Bonn Dezember 2008 (World Conference Center Bonn) Plenary Lectures: SERVICES OF CARE AND THEIR UTILIZATION Cohort studies: a link between biomedical and care research Abstract (taken from the Abstract Booklet): Health care interventions are mostly implemented at the level of organisations rather then at the level of individual patients or subjects; similarly the main forms of health care research are the systems and services for care. Yet, this line of research might miss the needs of patients. In samples of subjects selected from the population or patients from various treatment settings are needed to inform health care research. On the other hand, prospective cohort studies are considered to be ideal tools to derive markers and risk factors for early diagnosis and monitoring of the course of diseases. Yet, their potential for health service research, particularly in common neurodegenerative diseases is underappreciated. In this perspective the presentation will deal with three questions by reference to published and ongoing cohort studies in dementia (including the German AgeCoDe Study): (1) What can prospective cohort studies tell us about the patient needs? The broad interpersonal variation of modes of living with dementia, of the degree of decline and opportunities of coping, of associated disorders, impairments, disabilities and handicaps demonstrate the need for highly specialised and personalised care. Subgroups with specific vulnerabilities require particular attention.

2 (2) How can cohort studies contribute to the health care system in order to improve dementia care? Are population based cohort studies sufficient for this purpose? Tracking the course from premorbid states through early and late stages of dementia provides an ideal basis for detection of prevention strategies and comparisons between the available settings of care. This data set defines the background for measures of quality control, bench-marking and health economics as well as for the assessment of benefits emerging from innovative diagnostic, treatment and service strategies. (3) What type of cohort studies are needed to inform health service research? The scope of the aforementioned goals and targets requires long-term prospective cohort studies in various settings (i.e. parallel cohorts in the general population, primary care, specialized family care as well as institutionalized care), in different age cohorts (old, older and oldest-old) old) and in vulnerable subgroups (e.g. migrants, somatically ill and handicapped people). The observational nature of the cohort studies should not preclude international strategies in subcohorts Wolfgang Maier, Prof. Dr., Klinik für Psychiatrie und Psychotherapie, Universität Bonn, Bonn

3 Versorgungsforschung für demenziell erkrankte Menschen Health Services Research for People with Dementia Bonn, Dezember 2008 Prospective Cohort Studies: Linking Biomedical and Care Research W. Maier F. Jessen Forschergruppe FOR926

4 Research Paradigms in Public Health Randomised controlled trials Complex intervention studies Observational studies Prospective cohorts Cross-sectional samples

5 Research Paradigms in Public Health Research Complex Prospective intervention studies cohort studies Primary Care Specialised Medical Care Nursing Home Family Care Hospital Community Health

6 Cognition Model for the Relationship Between Cognitive Decline and Dementia in Subjects with Alzheimer's Disease Genetic and early environmental risk factors Late environmental risk factors Biomarkers/ Surrogat Surrogat markers markers MCI Dementia Subjective memory impairment or Cognitive decline MCI, cognitive norm deviation with/without dysfunction Dementia Age Early Detection Early Diagnosis Diagnosis Braak Stages I/II III/IV V/VI

7 Prospective Cohort Studies Impact on Health Services Subjective memory impairment/complaints: demands for public health programmes Prediction of dementia is feasible also in primary care: implications for disclosure of prognosis and diagnosis Cognitive decline prior and subsequent to diagnosis of dementia: demands for awareness and improved care in vulnerable groups

8 Dementia syndrome - Memory impairment as clinical symptom - Impairment in daily living Objective memory impairment/mci - Norm deviations in cognitive tests adjusted for age and education - No impairment in daily living Subjective memory impairment/complaints -Nocognitive impairment by tests - No impairment i in daily living i - Age-associated memory change -Nosubjective impairment/complaints -Noobjective impairment -No impairment in daily living

9 Proposal for Introducing the Health-Promoting Memory Initiative Elderly persons with memory problems Attending physician Specialized memory consultations Neuropsychological tests Diagnosis of dementia YES NO - Follow up - Multidimensional preventive interventions - Treating predisposing diseases - Organization of follow-up - Managment as part of the memory consultations If dementia is diagnosed (Gillette-Guyonnet et al., 2008; J Nutrit Health Aging 12: )

10 Physical Activity Improves Cognitive Functions in Subjects with Memory Compaints/ Subjective Memory Impairments ADAS-Cog (Change to baseline) 1.0 Experimental (n=69) 0.8 Controls (n=69) Worsening Mo 12 Mo 18 Mo 6 Mo 12 Mo 18 Mo Improvement (Lautenschlager et al. 2008; JAMA 300: )

11 Training Effects on Everyday Function (ACTIVE-Study): Self-Reported Instrumental Activities of Daily Living (IADL) Difficulty Scores Memory Reasoning Speed Control Baseline Year 1 Year 2 Year 3 Year 4 Year 5 (n=2802) (n=2325) (n=2234) (n=2101) (n=1877) Training Time (Willis et al., 2006; JAMA 296: )

12 Animal Models: Exercise Induces Growth Factor Cascades Inflammation Age-related cognitive decline Neurodegeneration (AD, PD) Neurotrophin resistance Exercise Metabolic syndrome Hypertension Insulin resistance Growth factor induction and signaling cascades BDNF, IGF1, VEGF Brain health Cognition Plasticity Neurogenesis Vascular function (Cotman et al., 2007; Trends Neurosci 30:

13 Prospective Prevalence of Alzheimer's Dementia in Germany Mio (n= ) Year (Based on Brookmeyer et al. 1998; Am J Publ Health 88: )

14 The Impact of Effective Prevention on the Prospective Prevalence of Alzheimer's Dementia in Germany Mio Year ½ Year 1Y Year 2 Years 5 Years 1.0 (n= ) Year (Based on Brookmeyer et al. 1998; Am J Publ Health 88: )

15 Prospective Cohort Studies Impact on Health Services Subjective memory impairment/complaints: demands for public health programmes Prediction of dementia is feasible also in primary care: implications for disclosure of prognosis and diagnosis Cognitive decline prior and subsequent to diagnosis i of dementia: demands for awareness and improved care in vulnerable groups

16 Biomarker-Supported Predictive Diagnosis of Alzheimer's Disease (AD) Derived from Prospective Cohort Studies in Memory Clinics Memory Impairment/MCI Predictive diagnosis of Alzheimer's disease/dementia Structural MRT Glucose PET Biomarker CSF Aβ Tau/pTau

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18 Early Alzheimer's Disease Diagnostics: Wait! Wait! Don't tell me! A dilemma: How do we respond? Early diagnostics for AD is the dark mirror of our own private future that the majority of us are not prepared to face. Those of us who have watched the indignity and painful distortions as a loved one s mind unravels are changed forever. None of us expects to know our futures with certainty, but each of us has a responsibility to be as well-informed as possible when it comes to planning that future, for ourselves and our families. To show the world a collective resistance to testing is a mixed message about how seriously we take the threat of this disease on the next generation and our own. I can only suggest from personal experience that endurance of unspeakable sadness and pain is not usually a politically active state. Endurance is private; the other creates noise. We are left too exhausted to protest; those who know their predisposition are empowered to demand a response on the public stage. (M. Comer 2008; Alzheimers Dement 4: )

19 Empirical Model to Explain Diversity of Attitudes to Early Screening for Dementia Knowledge consequences Perceived benefits Preventive behaviours Self-efficacy Intention to Screen Perceived susceptibility (Galvin et al., 2008; Alzheimers Dement 4: )

20 Prospective Cohort Studies Impact on Health Services Subjective memory impairment/complaints: demands for public health programmes Prediction of dementia is feasible also in primary care: implications for disclosure of prognosis and diagnosis Cognitive decline prior and subsequent to diagnosis i of dementia: demands for awareness and improved care in vulnerable groups

21 Model for the Relationship Between Cognitive Decline and Dementia in Subjects with Alzheimer's Disease Cognition age-associated memory changes SMI MCI Dementia Age

22 Cognitive Decline in Older Men by Living Situation: FINE Study (Gelder et al., 2006; J Gerontol B Psychol Sci Soc Sci 61: P213-P219)

23 Model for the Relationship Between Cognitive Decline and Dementia in Subjects with Alzheimer's Disease (Clinical Cohort Studies) Cognition low cognitive reserve high cognitive reserve SMI MCI Dementia need to be dressed nursing home placement Age

24 Model for the Relationship Between Cognitive Decline and Dementia in Subjects with Alzheimer's Disease (Clinical Cohort Studies) Cognition low cognitive reserve high cognitive reserve SMI MCI Dementia SCD SCD need to be dressed RCD RCD nursing home placement Age RCD: rapid cognitive decline, SCD: slow cognitive decline

25 Predictors and Correlates for Low Cognitive Reserve and Rapid Cognitive Decline (Emerging from Population-Based Cohort Studies): Educational level low Low socioeconomic status Previous: low work complexity Low level of social participation Cognitive and physical activity Loneliness Malnutrition C bidit l d Comorbidity load (particularly vascular disease, diabetes, frailty)

26 Relationship Between Cognitive Decline and Dementia in Subjects with Alzheimer's Disease Cognition low cognitive reserve high cognitive reserve SMI MCI Dementia SCD SCD RCD RCD REAL-FR-Study (2008) RCD: rapid cognitive decline (more then 5 MMSE decline per year): 11% SCD: slow cognitive decline (less then 3 MMSE decline): 23%

27 Rapid Cognitive Decline (RCD) Evidence from Observational Cohort Studies*: Initial RCD predicts future RCD (worse clinical course) Risk for malnutrition and weight loss Elevated mortality risk Attenuation through acetylcholine li esterase inhibitors * (Soto et al., 2008; J Nutr Health Aging 12: )

28 Consensus Statement on Dementia of Alzheimer Type in the Severe Stage B. Vellas,S. Gauthier, H. Allain, S. Andrieu, J.P. Aquino, G. Berrut, M. Berthel; F. Blanchard, V. Camus, J.F. Dartigues, B. Dubois, F. Forette, A. Franco, R. Gonthier, A. Grand, M.P. Hervy, C. Jeandel, M.E. Joel, P. Jouanny, F. Lebert, P. Michot, J.L. Montastruc, F. Nourhashemi, P.J. Ousset, J. Pariente, A.S. Rigaud, P. Robert, G. Ruault, D. Strubel, J. Touchon, M. Verny, J. M. Vetel Rapid Cognitive Decline in Alzheimer's Disease. Consensus Paper M.E. Soto, S. Andrieu, C. Arbus, M. Ceccaldi, P. Couratier, T. Dantoine, J.-F. Dartigues, S. Gillette-Guyonette, F. Nourhashemi, P.-J. Ousset, M. Poncet, F. Portet, J. Touchon, B. Vellas The Journal of Nutrition, Health & Aging, 2005, 9: ; 2008, 12:

29 Observational Prospective Cohort Studies Improve the Delivery of Health Care Prediction of dementia is feasible also in primary care Rapid cognitive decline requires special medical and care attendance and interventions Vulnerable populations are at elevated risk for dementia and rapid decline and are in need of awareness and specialized health care services

30 Subjects with Dementia and their Carers in a Longitudinal Community Study Question: Is "wellbeing" despite of adversity/dementia ti feasible? Answer: Yes, "wellbeing" persists unchanged despite of cognitive decline! Predisposing are preserved - mental health + - social relationships Laser-AD study, structural equation model: Livingston et al. 2008; J Neurol Neurosurg Psychiatry 79:

31 Which Kind of Prospective Cohort Studies are Needed to Improve Dementia Care? General elderly population (representative) Primary health care (representative, unselected for diagnoses) Diagnosis-specific specific clinical cohorts (case-control) - Community dwelling (representative) - Patients in specific settings of treatment/care?

32 Which Kind of Prospective Cohort Studies are Needed to Improve Dementia Care? General elderly population (representative) - increase sample size for complex interactions - develop biomarkers for early diagnosis i - explore long-term effects of interventions, extend to oldest old Primary health care (representative, unselected for diagnoses) - explore effects of early diagnosis on patients, families and care - investigate collaborative care effects Diagnosis-specific clinical cohorts (case-control) - Community dwelling (represenative) - Patients in specific settings of treatment/care? - explore determinants of speed of decline explore determinants of speed of decline - explore treatment effect - study late stages