Clearing The Fog of Geriatrics: Shifting Towards Complex System Thinking for the Health and Care of Older Adults Joshua J. Armstrong
PhD Candidate Aging, Health & Well-being PhD Program School of Public Health and Health Systems University of Waterloo
Introduction “The 80-year-old is not simply the 45-year-old, 35 years later. This truism is the essence of geriatric medicine and demands clinical approaches that are age-relevant and function oriented.” – Leslie S. Libow, MD
“There's a wonderful phrase: 'the fog of war.' What ‘the fog of war’ means is: war is so complex it's beyond the ability of the human mind to comprehend all the variables. Our judgment, our understanding, are not adequate.” – Robert S. McNamara 2
Today’s Agenda Shifting Demographics and Disease Patterns The Fog of Geriatrics Current Medical Thinking – The Biomedical Framework Shifting Medical Thinking - Complex Systems Framework in Geriatric Medicine Future Directions 3
Shifting Demographics and Disease Patterns Aging populations and the epidemiologic transition
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Shifting Demographics Canada’s age structure is shifting Increasing life expectancy Declining fertility rates
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TEN LEADING CAUSES OF DEATH in the United States - 1900 & 2004
Source: Epidemiology 4th Edition - Gordis 7
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Source: WHO Global Status Report on Noncommunicable Diseases 9
Impact on Health Care System In 2005, Statistics Canada reported that 65.4% of all deaths were caused by heart disease, cerebrovascular diseases, lower respiratory diseases, cancer and diabetes It is estimated that 76% of Canadians live with one or more chronic conditions With the aging of the Canadian population, chronic diseases will continue to be prevalent and will continue to be the leading causes of death Yet our current health care systems are not optimally designed to handle these chronic and complex issues Focus is on acute disease (and they are really good at this!) 10
Acute Disease Characteristics
Chronic Disease Characteristics
Abrupt onset Limited duration Usually a single cause Diagnosis and prognosis commonly accurate • Specific therapy available • Cure likely with return to normal health • Minimal uncertainty
• Gradual onset common • Unfolds over time • Multivariate causation, changing over time • Undulating course • Diagnosis often uncertain; Prognosis obscure • No cure; management over time necessary • Uncertainty pervasive
• • • •
Source: Halstead Holman, 2004 11
ď‚— Aging is an important marker of accumulation of risks for chronic disease. In other words, the impact of risk factors increase over the life course. ď‚— In order to compartmentalize this increased risk of multiple diseases/syndromes/symptoms with aging, the current medical system developed: GERIATRIC MEDICINE
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The Fog of Geriatrics
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Robert S. McNamara uses the term ‘fog of war’ to describe the uncertainty that is raised by the multifaceted situations that are often found in times of conflict. Similarly, geriatric medicine is packed with uncertainty, copious interacting and non-independent features, nonlinear relationships, and numerous potential outcomes (i.e., full recovery, mortality, hospitalization, institutionalization). This complexity in the health and care of older adults is what I have termed ‘the fog of geriatrics’. 14
What is geriatrics? Geriatrics is the branch of medicine that focuses on health promotion and the prevention and treatment of disease and disability in later life.
Multiple challenges when caring for older adults:
Aging as a risk factor for many chronic diseases Multimorbidity (>1 health issue simultaneously) Geriatric Syndromes Cognitive and functional decline Atypical presentation of acute illness Non-specific symptoms Expected physiological changes of aging Heterogeneity 15
Aging is a contributing risk factor for many chronic diseases and disorders • Alzheimer’s Disease • Frailty • Falls • Delirium • Osteoporosis • Depression
• Syncope • Myocardial infarction • Parkinson’s • Diabetes • Pressure Ulcers
• Pulmonary embolism • Lung Cancer • Heart failure • Hypertension • Arthritis • Malnutrition
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Breast Cancer Pneumonia COPD Heart Disease Stroke Adverse Drug Reactions
Aging is never necessary or sufficient as a determinant of disease due to the dense web of causal factors responsible for chronic diseases 16
Multimorbidity Geriatricians and the health care system increasingly are working with individuals with multiple coexisting diseases This is now the norm, it is no longer the exception. Of Canadian seniors (over the age of 65), 74% have one or more chronic disease
CIHI, 2011: http://secure.cihi.ca/cihiweb/products/airchronic_disease_aib_en.pdf
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CIHI, 2011: http://secure.cihi.ca/cihiweb/products/airchronic_disease_aib_en.pdf
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CIHI, 2011: http://secure.cihi.ca/cihiweb/products/airchronic_disease_aib_en.pdf
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Multimorbidity impacts: Individual well-being and disability status Health Care Usage: 24% of seniors (those with 3 or more chronic diseases) use 40% of the services (CIHI, 2011) Medication use: Polypharmacy Care management level: increases difficulty Care is often provided by multiple specialists (single disease focus) Limited evidence base for interventions
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Geriatric Syndromes Geriatric syndromes refers to clinical conditions in older persons that do not fit into discrete disease categories:
Frailty, falls, delirium, urinary incontinence, chronic pain
Heterogeneous
Typically involve multiple causal factors and multiple organ systems Potential for shared risk factors Common in older adults and have substantial implications for functioning and quality of life Little progress has been made in developing understanding of etiology or progression of these syndromes 21
Source: Geriatric Syndromes: Clinical, Research, and Policy Implications of a Core Geriatric22Concept - Inouye et al., 2007
ď‚— Despite the long-recognized challenges surrounding the health and care of older individuals, medical research has typically applied a reductionist approach when attempting to understand chronic disease etiology and care management (i.e., factor X leads to outcome Y). ď‚— Due to the complexities in geriatric medicine, reductionist approaches have fallen short in defining and understanding the many unexplained and prevalent medical issues faced by older adults. 23
Biomedical Framework Current Thinking
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Biomedical Model Currently, the science of medicine is dominated by a reductionist approach: Single factor/disease focus “one risk factor to one disease” approach in medical epidemiology
Biological focus (ignores psychological, social determinants) Linear thinking Additive treatments Polypharmacy 25
Modern medicine tends to view individuals as if they were a collections of subsets of physiologies that can be addressed and treated independently
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Acute Disease Characteristics Abrupt onset Limited duration Usually a single cause Diagnosis and prognosis commonly accurate • Specific therapy available • Cure likely with return to normal health • Minimal uncertainty • • • •
Chronic Disease Characteristics • Gradual onset common • Unfolds over time • Multivariate causation, changing over time • Undulating course • Diagnosis often uncertain; Prognosis obscure • No cure; management over time necessary • Uncertainty pervasive
Source: Halstead Holman, 2004: Patient Self-Management: A Key to Effectiveness and Efficiency 27 in Care of Chronic Disease
Source: The Limits of Reductionism in Medicine: Could Systems Biology Offer an Alternative? – Ahn et al., 2006 28
Shifting Thinking Applying Complex System Theory to Geriatrics
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Patients are considered by many as complex systems and health literature has shown a recent increase in papers related to complex systems. However, for geriatric patients, complex systems theory may help even more: Treatment for individuals with multimorbidity Currently unknown etiologies and pathologies: Alzheimer’s disease, frailty, Parkinson’s Improve clinicians ability to make care decisions in complex patients 30
Complex Systems Common features of complex systems 1. 2. 3. 4. 5. 6.
Composed of a multiplicity of things Dense web of causal connections Interdependence of their components Openness to outside systems Synergy Non-linear behaviour
The following slides will highlight these 6 features in relation to the health and care of older adults. 31
Older Adults as Complex Systems 1. Composed of a multiplicity of things Older adults are: Composed of multiple organ systems, tissues, and cells Often have multiple chronic diseases involving multiple organ systems Often take multiple medications to deal with multiple medical issues (polypharmacy) Care typically involves multiple providers Family doctor + specialists + informal care provider +… 32
Older Adults as Complex Systems 2. Dense web of causal connections
Dense connectivity within the human body Organ systems are interdependent
Multifactorial diseases For the complex diseases of aging, a single factor is rarely implicated as the sole determinant More likely that complex diseases are brought on by interactions and dynamics of multiple co-factors
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Older Adults as Complex Systems 3. Interdependence of their components Cells, tissues and organs work together to respond to environment to maintain health and life
Resilience in the human body Compensation (i.e., cognitive reserve’s role in Alzheimer’s disease)
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Older Adults as Complex Systems 4. Openess to outside systems Biopsychosocial determinants of health Nutrition greatly impacts health and chronic diseases
Environmental factors impact health and chronic diseases 5. Synergy or Emergence Diseases and syndromes can be considered as emergent properties of the human body Synergistic effect from causative factors 35
Older Adults as Complex Systems 6. Non-linearity Human beings are not machines but complex systems. Complex systems do not react in linear ways. Disease and syndrome etiology and progression should be modeled with non-linear conceptual schematics and non-linear analytic models Minor medical issues can cause death 36
Source: The Limits of Reductionism in Medicine: Could Systems Biology Offer an Alternative? – Ahn et al., 2006 37
Implications Clinical & Research
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Clinical Implications Treatment should be patient-centric and not diseasecentric Individualized treatments “It is much more important to known what sort of patient has a disease than to know what kind of disease a patient has”. –Sir William Osler
New evidence-based criteria and guidelines need to be developed for geriatric issues and syndromes Multidimensional and careful use of medication Emphasizes a holistic approach and the needs of the patient 39
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Research Implications The impact of broad interventions should be investigated in heterogeneous populations of older adults (exercise, nutrition, hormones) Geriatric medical research from a systems perspective will require input from a range of disciplines Methodological shift: Epidemiological models and quantitative methods for health data need to be developed and applied to geriatric data Complex models of pathophysiology need to be explored and tested Need to account for multiple pathways and potential synergism between pathways 41
New Etiological Models for Geriatric Syndromes
Source: Geriatric Syndromes: Clinical, Research, and Policy Implications of a Core Geriatric Concept - Inouye et al., 2007 42
New Etiological Models for Alzheimer’s Disease
Source: The etiology of age-related dementia is more 43 complicated than we think – McDonald et al., 2010
Source: Rising Tide Report http://www.alzheimer.ca/en/Get -involved/Raise-yourvoice/Rising-Tide
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Future Directions
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Machine Learning in Electronic Health Data ď‚— Traditional statistics methods are inadequate to handle both the complexity and the growing size of electronic health databases ď‚— Novel computer-based analytical techniques from disciplines such as data mining, machine learning, and mathematics have potential for enhancing understanding of geriatric health issues by examining non-linear phenomenon and discovering unknown patterns ď‚— Theory from complex systems can be used in combination with these tools for knowledge discovery 46
Critical Transitions Marten Scheffer delivered a WICI talk last year titled “Early Warning Signs for Critical Transitions” He has applied his knowledge on ecosystems of lakes to better understand the dynamics of complex systems This work using bifurcation analysis and catastrophe modeling has the potential to be applied to geriatric issues Frailty Alzheimer’s Disease 47
The End of the Disease Era Tinetti and Fried (2004): “The changed spectrum of health conditions, the complex interplay of biological and non-biological factors, the aging population, and the intraindividual variability in health priorities render medical care that is centered primarily on the diagnosis and treatment of individual diseases at best out of data and at worst harmful.” A shift towards a more integrated model based on the health care needs of patients in the 21st century is needed Complexity system framework has the potential to assist in the redesign of the health system 48
A few more directions… Applying discoveries from systems biology in medical research and clinical applications Epigenetics is a new field of research that would greatly benefit from a complex system thinking approach and modeling The obesity epidemic and its impact on healthy aging, population health, and our health care systems
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Conclusion There is a need for a shift to complex systems thinking in all of health and health care Especially important in geriatrics
Only a shift is needed…the biomedical approach has had many successes and will continue to improve and save lives Complex systems thinking has the potential: Uncover currently unknown disease aetiologies and pathologies in geriatrics Improve clinical decision making and clinical quality in older adults Elucidate patterns of chronic disease in our aging populations 50
Thank you for listening. Questions? Contact Josh ďƒ joshua.j.armstrong@gmail.com