Syndemics

Prevention Network

NIH Roadmap Methodology and Technology SummitBethesda, MD

August 21-22, 2006

Syndemic Thinking and Simulation Studies in Public Health Work

Bobby Milstein Syndemics Prevention NetworkCenters for Disease Control and

Preventionbmilstein@cdc.gov

Methodological Considerations in Interdisciplinary Health Behavior/Social Science Research

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Picture a Neighborhood Where…

• Conditions are not supportive of healthy living

• People are either afflicted by or at risk for numerous mutually reinforcing health problems

• Citizen leaders are making an effort to alleviate afflictions and improve living conditions, but their power is limited

• More could be done through local, broad-based organizing and with effective assistance from outside allies (e.g., philanthropy, government)James Nachtwey in Sachs J. How to end poverty.

Time Magazine 2005 March 14.

How does public health work typically proceed in such circumstances?

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Side Effects of Specialization

• Confusion, inefficiency, organizational disarray

• Competition for limited resources

• Attention to “local” causes, near in time and space

• Neglected feedback (+ and -)

• Confounded evaluations

• Coercive power dynamics

• Priority on a single value, implicitly or explicitly devaluing others

• Limited mandate to address context (living conditions) or infrastructure (public strength)

• Disappointing track record, especially with regard to inequalities

A

C

BD

E

A B C D EIssue Organizations

Neighborhood

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Diseases of Disarray

Hardening of the categories

Tension headache between treatment and prevention

Hypocommitment to training

Cultural incompetence

Political phobia

Input obsession

Wiesner PJ. Four disease of disarray in public health. Annals of Epidemiology. 1993;3(2):196-8.

Chambers LW. The new public health: do local public health agencies need a booster (or organizational "fix") to combat the diseases of disarray? Canadian Journal of Public Health 1992;83(5):326-8.

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A Complementary Science of Relationships

• Efforts to Reduce Population Health ProblemsProblem, problem solver, response

• Efforts to Organize a System that Assures Healthful Conditions for All Dynamic interaction among multiple problems, problem solvers, and responses

Institute of Medicine. The future of public health. Washington, DC: National Academy Press, 1988.

Institute of Medicine. The future of the public's health in the 21th century. Washington, DC: National Academy Press, 2002.

Bammer G. Integration and implementation sciences: building a new specialisation. Cambridge, MA: The Hauser Center for Nonprofit Organizations, Harvard University 2003.

True innovation occurs when things are put together for the first time that had been separate.

– Arthur Koestler

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Highlights the Dynamic and Democratic Dimensions of Public Health Work

PUBLIC HEALTH WORK

InnovativeHealth

Ventures

UNDERSTANDING CHANGESystems Science

• What causes population health problems?

• How are efforts to protect the public’s health organized?

• How and when do health systems change (or resist change)?

SETTING DIRECTIONPublic Health

What are health leaderstrying to accomplish?

GOVERNING MOVEMENTSocial Navigation

Directing Change

Charting Progress

• Who does the work?• By what means?• According to whose values?

• How are conditions changing?• In which directions?

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New Word for a Familiar Phenomenon

Singer M, Snipes C. Generations of suffering: experiences of a treatment program for substance abuse during pregnancy. Journal of Health Care for the Poor and Underserved 1992;3(1):222-34.

Singer M. 1994. AIDS and the health crisis of the US urban poor: The perspective of critical medical anthropology. Social Science and Medicine 39(7): 931-948.

Singer M. 1996. A dose of drugs, a touch of violence, a case of AIDS: Conceptualizing the SAVA syndemic. Free Inquiry in Creative Sociology 24(2): 99-110.

Singer M, Clair S. Syndemics and public health: reconceptualizing disease in bio-social context. Medical Anthropology Quarterly 2003;17(4):423-441.

“We have introduced the term ‘syndemic’ to refer to

the set of synergistic or intertwined and mutually

enhancing health and social problems facing the urban

poor.  Violence, substance abuse, and AIDS, in this

sense, are not concurrent in that they are not

completely separable phenomena.”

-- Merrill Singer

What was Singer doing?

How might this perspective transform public health science?

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Boundary Judgments(System of Reference)

Observations(Facts)

Evaluations(Values)

Ulrich W. Boundary critique. In: Daellenbach HG, Flood RL, editors. The Informed Student Guide to Management Science. London: Thomson; 2002. p. 41-42. <http://www.geocities.com/csh_home/downloads/ulrich_2002a.pdf>.

Ulrich W. Reflective practice in the civil society: the contribution of critically systemic thinking. Reflective Practice 2000;1(2):247-268. http://www.geocities.com/csh_home/downloads/ulrich_2000a.pdf

Midgley G. The sacred and profane in critical systems thinking. Systems Practice 1992;5:5-16.

Boundary Critique“Experts cannot justify their boundary judgments by referring to an advantage of

theoretical knowledge and expertise. When it comes to the problem of boundary judgments, experts have no natural advantage of competence over lay people.”

-- Werner Ulrich

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Epi·demic

• The term epidemic is an ancient word signifying a kind of relationship wherein something is put upon the people

• Epidemiology first appeared just over a century ago (in 1873), in the title of J.P. Parkin's book "Epidemiology, or the Remote Cause of Epidemic Diseases“

• Ever since then, the conditions that cause health problems have increasingly become matters of public concern and public work

Elliot G. Twentieth century book of the dead. New York,: C. Scribner, 1972.

Martin PM, Martin-Granel E. 2,500-year evolution of the term epidemic. Emerging Infectious Diseases 2006. Available from http://www.cdc.gov/ncidod/EID/vol12no06/05-1263.htm

National Institutes of Health. A Short History of the National Institutes of Health. Bethesda, MD: 2006. Available from http://history.nih.gov/exhibits/history/

Parkin J. Epidemiology; or the remote cause of epidemic diseases in the animal and the vegetable creation. London: J and A Churchill, 1873.

A representation of the cholera epidemic of the nineteenth century.Source: NIH

“The pioneers of public health did not change nature, or men, but adjusted the active relationship of men to certain aspects of nature so that the relationship became one of watchful and healthy respect.”

-- Gil Elliot

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Syn·demic

• The term syndemic, first used in 1992, strips away the idea that illnesses originate from extraordinary or supernatural forces and places the responsibility for affliction squarely within the public arena

• It acknowledges relationships and signals a commitment to studying population health as a a fragile, dynamic state requiring continual effort to maintain and one that is imperiled when social and physical forces operate in harmful ways

Confounding

Connecting*

Synergism

Syndemic

Events

System

Co-occurring

* Includes several forms of connection or inter-connection such as synergy, intertwining, intersecting, and overlapping

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Changing (and Accumulating) Ideas in Causal Theory

What Accounts for Poor Population Health?

• God’s will

• Humors, miasma, ether

• Poor living conditions, immorality (e.g., sanitation)

• Single disease, single cause (e.g., germ theory)

• Single disease, multiple causes (e.g., heart disease)

• Single cause, multiple diseases (e.g., tobacco)

• Multiple causes, multiple diseases (but no feedback dynamics) (e.g., multi-level modeling)

• Dynamic feedback among afflictions, living conditions, and public strength (e.g., syndemic orientation)

1880

1950

1960

1980

2000

1840

Richardson GP. Feedback thought in social science and systems theory. Philadelphia, PA: University of Pennsylvania Press, 1991.

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Seeing Syndemics

• The word syndemic signals special concern for many kinds of relationships:

– mutually reinforcing health problems

– health status and living conditions

– synergy/fragmentation in the health protection system (e.g., by issues, sectors, organizations, professionals and other citizens)

Milstein B. Spotlight on syndemics. Centers for Disease Control and Prevention, 2001. <http://www.cdc.gov/syndemics>

“You think you understand two because you understand one and one. But you must also understand ‘and’.”

-- Sufi Saying

• It is one of a few approaches that explicitly includes within it our power to respond, along with an understanding of its changing pressures, constraints, and consequences

Health

LivingConditions

PublicStrength

A syndemic orientation clarifies the dynamic and democratic character of

public health work

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What Do These Observations Have in Common?

• Road building programs increase traffic, delays, and pollution

• Low tar and nicotine cigarettes increase carcinogen intake

• Antilock brakes cause some to drive more aggressively

• Forest fire suppression leads to larger, hotter, and more dangerous fires

• Flood control efforts lead to more severe floods and excess cost

• Antibiotics stimulate the evolution of drug-resistant pathogens

• Pesticides and herbicides stimulate the evolution of resistant pests and accumulate up the food chain to poison fish, birds, and humans

• Antiretroviral treatment reduces mortality among those with HIV, but has increased risky behaviors, causing a rebound in incidence

Sterman JD. Learning from evidence in a complex world. American Journal of Public Health 2006;96(3):505-514.

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Understanding Policy Resistance

Meadows DH, Richardson J, Bruckmann G. Groping in the dark: the first decade of global modelling. New York, NY: Wiley, 1982.

Merton RK. The unanticipated consequences of purposive social action. American Sociological Review 1936;1936:894-904.

Forrester JW. Counterintuitive behavior of social systems. Technology Review 1971;73(3):53-68.

Policy resistance is the tendency for interventions to be delayed, diluted, or defeated by the response of the system to the intervention itself.

-- Meadows, Richardson, Bruckman

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Misleading Framing Assumptions

• Focus on the events

• Everything that happens must have a cause

• That cause must be close in time and space– Instantaneous impacts

– Causality runs one-way

– Independence

– Impacts are linear and constant

• Stepwise progress will lead to system wide improvement

Richmond B, Peterson S, High Performance Systems Inc. An introduction to systems thinking. Hanover NH: High Performance Systems, 1997.

These assumptions overlook non-local forces of change, such as feedback, accumulation, delay, and non-linear response

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Matching Appropriate Concepts and Methods

System Dynamics*

SocialNavigation*

POLICYDEVELOPMENT

ASSESSMENT

ASSURANCE

NetworkAnalysis*

CategoricalOrientationSyndemic

Orientation

X Y

What causes what? (feedback data)

What links to what? (proximity data)

Where are we?Where are we going?

(directional data)

* Examples selected from a larger class of system-oriented techniques

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System Dynamics Was Designed to Address Problems Marked By Dynamic Complexity

Good at Capturing

• Differences between short- and long-term consequences of an action

• Time delays (e.g., transitions, detection, response)

• Accumulations (e.g., prevalence, capacity)

• Behavioral feedback (e.g., actions trigger reactions)

• Nonlinear causal relationships (e.g., effect of X on Y is not constant)

• Differences or inconsistencies in goals/values among stakeholders

Forrester JW. Industrial dynamics. Cambridge, MA: MIT Press, 1961.

Sterman JD. Business dynamics: systems thinking and modeling for a complex world. Boston, MA: Irwin McGraw-Hill, 2000.

Homer JB, Hirsch GB. System dynamics modeling for public health: background and opportunities. American Journal of Public Health 2006;96(3):452-458.

Origins

• Jay Forrester, MIT (from late 1950s)

• Public policy applications starting late 1960s

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Time Series Models

Describe trends

Multivariate Stat Models

Identify historical trend drivers and correlates

Patterns

Structure

Events

Increasing:

• Depth of causal theory

• Degrees of uncertainty

• Robustness for longer-term projection

• Value for developing policy insights

Increasing:

• Depth of causal theory

• Degrees of uncertainty

• Robustness for longer-term projection

• Value for developing policy insights

Dynamic Simulation Models

Anticipate new trends, learn about policy consequences,

and set justifiable goals

Tools for Policy Analysis

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Sterman J. Business dynamics: systems thinking and modeling for a complex world. Boston, MA: Irwin McGraw-Hill, 2000.

Barriers to Learning in Dynamic Systems

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But We Can Create Virtual Worlds for Learning

Sterman J. Business dynamics: systems thinking and modeling for a complex world. Boston, MA: Irwin McGraw-Hill, 2000.

“In [dynamically complex] circumstances simulation becomes the only reliable way to test a hypothesis and evaluate the likely effects of policies."

-- John Sterman

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Selected CDC Projects Featuring System Dynamics Modeling, 2001-2006

• Syndemics Mutually reinforcing afflictions

• Diabetes In an era of rising obesity

• ObesityLifecourse consequences of changes in caloric balance

• Infant HealthFetal and infant morbidity/mortality

• PolioReintroductions after eradication

• HypertensionImproving detection and control

Milstein B, Homer J. Background on system dynamics simulation modeling, with a summary of major public health studies. Atlanta, GA: Syndemics Prevention Network, Centers for Disease Control and Prevention; February 1, 2005. <http://www2.cdc.gov/syndemics/pdfs/SD_for_PH.pdf>.

• Grantmaking ScenariosTiming and sequence of neighborhood health investments

• Upstream-Downstream EffortBalancing disease treatment with prevention and protection

• Healthcare ReformRelationships among cost, quality, equity, and health status

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System Modeling SupportsNavigational Policy Dialogues

Prevalence of Diagnosed Diabetes, US

0

10

20

30

40

1980 1990 2000 2010 2020 2030 2040 2050

Mill

ion

pe

op

le

HistoricalData

Markov Model Constants• Incidence rates (%/yr)• Death rates (%/yr)• Diagnosed fractions(Based on year 2000 data, per demographic segment)

Honeycutt A, Boyle J, Broglio K, Thompson T, Hoerger T, Geiss L, Narayan K. A dynamic markov model for forecasting diabetes prevalence in the United States through 2050. Health Care Management Science 2003;6:155-164.

Jones AP, Homer JB, Murphy DL, Essien JDK, Milstein B, Seville DA. Understanding diabetes population dynamics through simulation modeling and experimentation. American Journal of Public Health 2006;96(3):488-494.

Markov Forecasting Model

Simulation Experiments

in Action Labs

Trend is not destiny!

How?

Why?

Where?

Who?

What?

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Simulations for Learning in Dynamic Systems

Morecroft JDW, Sterman J. Modeling for learning organizations. Portland, OR: Productivity Press, 2000.

Sterman JD. Business dynamics: systems thinking and modeling for a complex world. Boston, MA: Irwin McGraw-Hill, 2000.

Sterman JD. Learning from evidence in a complex world. American Journal of Public Health 2006;96(3):505-514.

Sterman JD. All models are wrong: reflections on becoming a systems scientist. System Dynamics Review 2002;18(4):501-531.

Multi-stakeholder Dialogue

Dynamic Hypothesis (Causal Structure)

“The future is not to be predicted, but created.”

-- Arthur C. Clarke

Plausible Futures (Policy Experiments)

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“Simulation is a third way of doing science.

Like deduction, it starts with a set of explicit

assumptions. But unlike deduction, it does not

prove theorems. Instead, a simulation generates

data that can be analyzed inductively. Unlike

typical induction, however, the simulated data

comes from a rigorously specified set of rules

rather than direct measurement of the real world.

While induction can be used to find patterns in

data, and deduction can be used to find

consequences of assumptions, simulation

modeling can be used as an aid to intuition.”

-- Robert Axelrod

Axelrod R. Advancing the art of simulation in the social sciences. In: Conte R, Hegselmann R, Terna P, editors. Simulating Social Phenomena. New York, NY: Springer; 1997. p. 21-40. <http://www.pscs.umich.edu/pub/papers/AdvancingArtofSim.pdf>.

Sterman JD. Business Dynamics: Systems Thinking and Modeling for a Complex World. Boston, MA: Irwin McGraw-Hill, 2000.

Simulation ExperimentsOpen a Third Branch of Science

“The complexity of our mental models vastly exceeds our ability to understand their implications without simulation."

-- John Sterman

How?

Where?

0

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20

30

40

50

1960-62 1971-74 1976-80 1988-94 1999-2002

Prevalence of Obese Adults, United States

Why?

Data Source: NHANES 20202010

Who?

What?

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An Alternative Philosophical Tradition

Shook J. The pragmatism cybrary. 2006. Available at <http://www.pragmatism.org/>.

Addams J. Democracy and social ethics. Urbana, IL: University of Illinois Press, 2002.

West C. The American evasion of philosophy: a genealogy of pragmatism. Madison, WI: University of Wisconsin Press, 1989.

"Grant an idea or belief to be true…what concrete difference will its being true make in anyone's actual life?

-- William James

Pragmatism• Begins with a response to a perplexity or injustice

in the world• Learning through action and reflection• Asks, “How does this work make a difference?”

Positivism • Begins with a theory about the world• Learning through observation and falsification• Asks, “Is this theory true?”

We are not talking about theories to explain, but conceptual, methodological, and moral orientations: the frames of reference

that shape how we think, how we act, how we learn, and what we value

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• All models, including simulations, are wrong: incomplete and imprecise

• But some are better than others and capture more important aspects of the real world’s dynamic complexity

• A valuable model is one that can help us understand and anticipate better than we do with the unaided mind

How Should We Value Simulation Studies?

Artist: Rene Magritte

Sterman JD. All models are wrong: reflections on becoming a systems scientist. System Dynamics Review 2002;18(4):501-531.

Meadows DH, Richardson J, Bruckmann G. Groping in the dark: the first decade of global modelling. New York, NY: Wiley, 1982.

Forrester JW. Counterintuitive behavior of social systems. Technology Review 1971;73(3):53-68.

“All models are wrong, some are useful.”

-- George Box

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Syndemic Orientation

Expanding Public Health Science“Public health imagination involves using science to expand the

boundaries of what is possible.”

-- Michael Resnick

EpidemicOrientation

People inPlaces

EcologicalThinking

Governing Dynamics

Ca

us

al

Ma

pp

ing

Plausible Futures

DynamicModeling

Navigational Freedoms

De

mo

cra

tic

Pu

bli

c W

ork

Syndemics

Prevention Network

For Additional Informationhttp://www.cdc.gov/syndemics