International Society for Systems ScienceMadison, WI
July 14, 2008
International Society for Systems ScienceMadison, WI
July 14, 2008
Syndemics, Simulation Scenarios, and Social Change
Syndemics, Simulation Scenarios, and Social Change
Bobby Milstein Syndemics Prevention Network
Centers for Disease Control and [email protected]
http://www.cdc.gov/syndemics
Bobby Milstein Syndemics Prevention Network
Centers for Disease Control and [email protected]
http://www.cdc.gov/syndemics
Crafting a Health System that Protects Us All
Crafting a Health System that Protects Us All
Average Number of Adult Unhealthy Days per Month
4
5
6
7
1993 1995 1997 1999 2001 2003 2005
Year
Public Health Systems Science Addresses Navigational Policy Questions
Public Health Systems Science Addresses Navigational Policy Questions
17% increase
Centers for Disease Control and Prevention. Health-related quality of life: prevalence data. National Center for Chronic Disease Prevention and Health Promotion, 2007. Accessed October 23, 2007 at <http://apps.nccd.cdc.gov/HRQOL/index.asp>.
Milstein B. Hygeia's constellation: navigating health futures in a dynamic and democratic world. Atlanta, GA: Centers for Disease Control and Prevention; April 15, 2008.
How?
Why?
Where?
Who?
What?
2010 2025 2050
Americans’ Views on the Health SystemPoised for Significant Change?
Americans’ Views on the Health SystemPoised for Significant Change?
Over 75% of Americans think the current system
needs fundamental change
Over 75% of Americans think the current system
needs fundamental change
Blendon RJ, Altman DE, Deane C, Benson JM, Brodie M, Buhr T. Health care in the 2008 presidential primaries. New England Journal of Medicine 2008;358(4):414-422.
Lessons from Previous Health Reform VenturesLessons from Previous Health Reform Ventures
Heirich M. Rethinking health care: innovation and change in America. Boulder CO: Westview Press, 1999.
Kari NN, Boyte HC, Jennings B. Health as a civic question. American Civic Forum, 1994. Available at <http://www.cpn.org/topics/health/healthquestion.html>.
Meadows DH, Richardson J, Bruckmann G. Groping in the dark: the first decade of global modelling. New York, NY: Wiley, 1982.
Prior efforts were largely disappointing because of…
• Piecemeal approaches
• Complicated schemes that were opposed by special interests
• Assumption that healthcare dynamics are separate from other areas of public concern
Conventional analytic methods make it difficult to…
• Observe the health system as a large, dynamic enterprise
• Craft high-leverage strategies that can overcome policy resistance
Prior efforts were largely disappointing because of…
• Piecemeal approaches
• Complicated schemes that were opposed by special interests
• Assumption that healthcare dynamics are separate from other areas of public concern
Conventional analytic methods make it difficult to…
• Observe the health system as a large, dynamic enterprise
• Craft high-leverage strategies that can overcome policy resistance
Policy resistance is the tendency for interventions to be delayed, diluted, or defeated by the response of the system to the intervention itself.
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-- Meadows, Richardson, Bruckman
Expanding Options through Boundary Critique
Expanding Options through Boundary Critique
-- Julie GerberdingCDC Director
-- Julie GerberdingCDC Director
Rubin R. CDC campaign hopes to make USA healthier nation. USA Today 2008 July 7. <http://www.usatoday.com/news/health/2008-07-07-cdc-gerberding_N.htm>
Park A. Time 100: the people who shape our world. Time Magazine 2004 April 26.
“The debate about healthcare reform needs to be enriched by including the
concepts of health protection and health equity…and [we] have never
had a better opportunity to truly influence how we get from where we
are to wherever the new health system will be.”
“The debate about healthcare reform needs to be enriched by including the
concepts of health protection and health equity…and [we] have never
had a better opportunity to truly influence how we get from where we
are to wherever the new health system will be.”
Appreciating the Wider Scope of the “Health Challenge”Health > Healthcare
Appreciating the Wider Scope of the “Health Challenge”Health > Healthcare
The Promise of a Syndemic OrientationThe Promise of a Syndemic Orientation
A syndemic orientation clarifies the dynamic and democratic character
of public health work
Milstein B. Hygeia's constellation: navigating health futures in a dynamic and democratic world. Atlanta, GA: Syndemics Prevention Network, Centers for Disease Control and Prevention; April 15, 2008. http://www.cdc.gov/syndemics/monograph/index.htm
“You think you understand two because you understand one and one. But you must also understand ‘and’.”
-- Sufi Saying
“You think you understand two because you understand one and one. But you must also understand ‘and’.”
-- Sufi Saying
Studying innovations in public health work where there are multiple interacting problems
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)
Studying innovations in public health work where there are multiple interacting problems
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)
Health
LivingConditions
Power toAct
“Health Policy”
“Social Policy”
“Citizen-ship”
Explicitly includes our power to respond, while understanding its changing pressures, constraints, and consequences
Explicitly includes our power to respond, while understanding its changing pressures, constraints, and consequences
Epi·demic 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
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
“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
Syn·demic 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 understanding population health as a fragile, dynamic state requiring continual effort to maintain and one that is imperiled when social and physical forces operate in harmful ways
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 understanding population health as 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
Time Series Models
Describe trends
Multivariate Statistical Models
Identify historical trend drivers and correlates
Patterns
Structure
Events
Increasing:
• Depth of causal theory
• Robustness for longer-term projection
• Value for developing policy insights
• Degrees of uncertainty
• Leverage for change
Increasing:
• Depth of causal theory
• Robustness for longer-term projection
• Value for developing policy insights
• Degrees of uncertainty
• Leverage for changeDynamic Simulation Models
Anticipate new trends, learn about policy consequences,
and set justifiable goals
Tools for Policy Planning & EvaluationTools for Policy Planning & Evaluation
CDC’s Growing Portfolio of Health System Dynamics Projects
CDC’s Growing Portfolio of Health System Dynamics Projects
Selected Health Priority Areas…DiabetesObesityInfant healthCardiovascular healthSyndemics
Overall Health Protection Enterprise…Neighborhood transformationNational health economyChronic illness dynamicsUpstream-downstream investmentsHealth protection game
Communications, Training, Funding…Publications, special issues, monographsInteractive workshops, symposiaFunding announcementsWebsite, listservProfessional network
Selected Health Priority Areas…DiabetesObesityInfant healthCardiovascular healthSyndemics
Overall Health Protection Enterprise…Neighborhood transformationNational health economyChronic illness dynamicsUpstream-downstream investmentsHealth protection game
Communications, Training, Funding…Publications, special issues, monographsInteractive workshops, symposiaFunding announcementsWebsite, listservProfessional network
Where to Begin with a Problem as Vast as Health System Change?
Learn to How Succeed in a Simpler, Simulated System
Where to Begin with a Problem as Vast as Health System Change?
Learn to How Succeed in a Simpler, Simulated System
Madon T, Hofman KJ, Kupfer L, Glass RI. Implementation science. Science 2007;318(5857):1728-1729.
Milstein B, Homer J, Hirsch G. The health protection game: prototype design, preliminary insights, and future directions. Atlanta, GA: Centers for Disease Control and Prevention; May 8, 2008.
Is it too audacious to think about representing the entire U.S. health protection enterprise?
Is it too audacious to think about representing the entire U.S. health protection enterprise?
Definitely, if we study every detail up close…Definitely, if we study every detail up close…
Not if we take a macroscopic view, from a very particular distance…
Not if we take a macroscopic view, from a very particular distance…
Trajectory of Hurricane Andrew: August 23, 24 and 25, 1992
Richardson GP. Feedback thought in social science and systems theory. Philadelphia, PA: Univ. of Pennsylvania Press, 1991.
Milstein B. Hygeia's constellation: navigating health futures in a dynamic and democratic world. Atlanta, GA: Syndemics Prevention Network, Centers for Disease Control and Prevention; April 15, 2008.
Rosnay J. The macroscope: a new world scientific system. New York, NY: Harper & Row, 1979.
White F. The overview effect: space exploration and human evolution. 2nd ed. Reston VA: American Institute of Aeronautics and Astronautics, 1998.
Expand insurance coverage
Improve quality of care
Change reimbursement rates
Improve operational efficiency
Simplify administration
Encourage provider training/practice
Enable healthier behaviors
Build safer environments
Create pathways to advantage
Strengthen leadership
Expand insurance coverage
Improve quality of care
Change reimbursement rates
Improve operational efficiency
Simplify administration
Encourage provider training/practice
Enable healthier behaviors
Build safer environments
Create pathways to advantage
Strengthen leadership
Ingredients for Transforming Population HealthA Short Menu of Policy Proposals
Ingredients for Transforming Population HealthA Short Menu of Policy Proposals
Rules of the Health Protection GameRules of the Health Protection GameGoal Navigate the U.S. health system toward greater health and equity
TaskPrioritize intervention options across 10 policy domains
DecisionsCraft health protection strategies over 8 rounds (from 2010-2050), using feedback available every five years
ScoringAchieve the best results across four criteria simultaneously
Save lives (i.e., reduce the mortality rate)
Improve well-being (i.e., reduce unhealthy days)
Achieve equity (i.e., reduce unhealthy days due to Disadvantage)
Lower healthcare spending (i.e., reduce expenses per capita)
Appropriate implementation expenses (i.e., subsidy, program cost)
Game SetupA population in dynamic equilibrium, with fixed rates of birth and net immigration, experiencing high starting levels of mortality, unhealthy life, social inequity, and healthcare costs
No changes due to trends originating outside the health sector (e.g., aging, migration, economic cycles, technology, climate change)
Navigating Health FuturesGetting Out of a Deadly, Unhealthy, Inequitable, and Costly Trap
Navigating Health FuturesGetting Out of a Deadly, Unhealthy, Inequitable, and Costly Trap
Four Problems in the Current System: High Morbidity, Mortality, Inequity, Cost
Death rate per thousandUnhealthy days per capita
Health inequity indexHealthcare spend per capita
10
6
0.2
6,000
0
0
0
4,000
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
How far can you move
the system?
High-Level Map of Health System DynamicsHigh-Level Map of Health System Dynamics
Health carecosts
Sufficiency ofproviders
Provider netincome
Reimbursementrates
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Operational &administrative
overhead-
Insurancecoverage
-
Healthequity
Behavioralrisks Quality
of care
--
Number ofproviders
-
Socioeconomicdisadvantage
-
- Attractiveness ofhealth careprofessions
-
Environmentalhazards
Incentives forprovider training
and practice
Most parts of the health system—so often discussed separately—are in fact connectedMost parts of the health system—so often discussed separately—are in fact connected
Adapted from: Milstein B, Homer J, Hirsch G. Leading health system change using The Health Protection Game. Syndemics Prevention Network, Centers for Disease Control and Prevention; Work in Progress, May 2008. DRAFT: May 8, 2008
Strong public leadership is needed to change the modifiable drivers
(shown in italics)
Strong public leadership is needed to change the modifiable drivers
(shown in italics)
Main Health System Dynamics Main Health System Dynamics Risk, Disease, Health Status, and CostsRisk, Disease, Health Status, and Costs
Health carecosts
Diseaseprevalence
Morbidity &mortality
Behavioralrisks
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Effective Health Care is Powerful—and ExpensiveEffective Health Care is Powerful—and Expensive
Health carecosts
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Behavioralrisks
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Insurance Coverage Enables AccessInsurance Coverage Enables Access
Health carecosts
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Insurancecoverage
-
Behavioralrisks
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Disadvantage Creates a Double Vulnerability Disadvantage Creates a Double Vulnerability
Health carecosts
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Insurancecoverage
-
Behavioralrisks
Socioeconomicdisadvantage
-
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Demand Affects the Sufficiency of ProvidersDemand Affects the Sufficiency of Providers
Health carecosts
Sufficiency ofproviders
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Insurancecoverage
-
Behavioralrisks
--
Socioeconomicdisadvantage
-
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Cutting Reimbursements May Control CostCutting Reimbursements May Control Cost
Health carecosts
Sufficiency ofproviders
Reimbursementrates
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Insurancecoverage
-
Behavioralrisks
--
Socioeconomicdisadvantage
-
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Reimbursement Also Affects Quality Reimbursement Also Affects Quality
Health carecosts
Sufficiency ofproviders
Reimbursementrates
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Insurancecoverage
-
Behavioralrisks Quality
of care
---
Socioeconomicdisadvantage
-
Environmentalhazards
Main Health System Dynamics Main Health System Dynamics Reimbursement Further Affects Profit and AttractivenessReimbursement Further Affects Profit and Attractiveness
Health carecosts
Sufficiency ofproviders
Provider netincome
Reimbursementrates
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Operational &administrative
overhead-
Insurancecoverage
-
Behavioralrisks Quality
of care
--
Number ofproviders
-
Socioeconomicdisadvantage
- Attractiveness ofhealth careprofessions
Environmentalhazards
Incentives forprovider training
and practice
Main Health System Dynamics Main Health System Dynamics Health Equity Captures the Consequences of Differences in
Vulnerability, Health Status, and Access to Care Health Equity Captures the Consequences of Differences in
Vulnerability, Health Status, and Access to Care
Health carecosts
Sufficiency ofproviders
Provider netincome
Reimbursementrates
Diseaseprevalence
Morbidity &mortality
Effective healthcare provision
--
Health careaccess
Operational &administrative
overhead-
Insurancecoverage
-
Healthequity
Behavioralrisks Quality
of care
--
Number ofproviders
-
Socioeconomicdisadvantage
-
- Attractiveness ofhealth careprofessions
-
Environmentalhazards
Incentives forprovider training
and practice
Strong public leadership is needed to change the modifiable drivers
(shown in italics)
Strong public leadership is needed to change the modifiable drivers
(shown in italics)
Parameter Proxy Initial Values (~2000) Sources
Advantaged & Disadvantaged
Prevalence
Household Income (< or ≥ $25,000)
Advantaged = 79% Disadvantaged = 21%
Census
Selected Estimates for Model CalibrationSelected Estimates for Model Calibration
Parameter Proxy Initial Values (~2000) Sources
Advantaged & Disadvantaged
Prevalence
Household Income (< or ≥ $25,000)
Advantaged = 79% Disadvantaged = 21%
Census
Symptomatic Disease/Injury
Prevalence
Self-rated health is good, fair, or poor
Overall = 27% D/A Ratio = 1.60 (= 38.5%/24%)
BRFSS JAMA
Asymptomatic Chronic Disease Prevalence
High blood pressure (HBP) High cholesterol (HC) Asymp = Tot Chron – Symp
Overall = 40% (54.5% tot chron - 14.5% Symp)
D/A Ratio (tot chronic) = 1.15 (= 61%/53%)
NHANES JAMA
Mortality Deaths per 1,000 Overall = 8.4 D/A Ratio = 1.80
Vital Statistics AJPH
Morbidity Unhealthy days
per month per capita Overall = 5.25 D/A Ratio = 1.78
BRFSS
Health Equity Unhealthy days (or deaths)
attributable to disadvantage Attrib. fraction (unhealthy days) = 14.1% Attrib. fraction (deaths) = 14.4%
Census BRFSS
Health Insurance Lack of insurance coverage Overall = 15.6% D/A Ratio = 1.82
Census
Sufficiency of Primary Care Providers
Number of PCPs per 10,000 Overall = 8.5 per 10,000 D/A Ratio = 0.71
AMA Austin Study
Emergency Care for Nonurgent Problems
Acute non-urgent visits in ER or outpatient department
Overall = 19% D/A Ratio = 5.5
NAMCS
Unhealthy Behavior Prevalence
Smoking Physical inactivity
Overall = 34% D/A Ratio = 1.67
BRFSS JAMA Austin Study
Unsafe Environment Prevalence
“Neighborhood not safe” Overall = 26% D/A Ratio = 2.5
BRFSS JAMA Austin Study
Selected Estimates for Model CalibrationSelected Estimates for Model Calibration
Intervention Options & Scoring Criteria Intervention Options & Scoring Criteria
Illustrative Intervention Scenarios Illustrative Intervention Scenarios
Scenario Name
Policy Options
Insurance Coverage
QualityCare
Reimb.Rates
EfficiencySimpler Admin
ProviderIncentives
Healthier Behavior
Safer Environ
AdvantageStronger
Leadership
Cut Reimbursement*
Universal Coverage
Higher Quality
Upstream Protection
Others/Combos…
* The reimbursement cut is relative to health care input factor costs (labor, services, overhead). In model, this is done as an absolute cut. In real life, it could represent a freeze in reimbursements relative to ongoing inflation in factor costs.
Exploring Intervention ScenariosCut Reimbursements to Office-Based Physicians by 20%
Exploring Intervention ScenariosCut Reimbursements to Office-Based Physicians by 20%
Scoring Criteria: Deaths, Unhealthy Days, Inequity, Spending
Death rate per 1,000
Unhealthy days Health inequity index Healthcare spending per capita
>>>> These results are from a prototype model.<<<< Please do not cite or quote without permission.c
>>>> These results are from a prototype model.<<<< Please do not cite or quote without permission.c
10 6
0.2 6,000
7.5 4.5
0.15 5,500
5 3
0.1 5,000
2.5 1.5
0.05 4,500
0 0
0 4,000
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Prototype Model Output
Exploring Intervention ScenariosCut Reimbursements to Office-Based Physicians by 20%
Exploring Intervention ScenariosCut Reimbursements to Office-Based Physicians by 20%
Quality of disease & injury care Quality of DI care for the managed
Sufficiency of primary care providers
Advantaged
Disadvantaged
Prototype Model Output
Prototype Model Output
Prototype Model Output
1
0.9
0.8
0.7
0.62000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
1
0.75
0.5
0.25
02000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Advantaged
Disadvantaged
1
0.875
0.75
0.625
0.5
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Acute nonurgent event visits to ER or OPD70 M
55 M
40 M
25 M
10 M
2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
Advantaged
Disadvantaged
Prototype Model Output
Additional Preliminary FindingsAdditional Preliminary FindingsUniversal Coverage (with Leadership)
Lowers morbidity and mortality quickly
Increases cost significantly (greater volume of mediocre services, which do little to prevent disease)
Worsens inequity (greater demand exacerbates pre-existing provider shortage for disadvantaged)
Quality of Care (with Leadership)
Lowers morbidity and mortality quickly, more so than “Universal Coverage” (more people benefit)
Costs rise initially, then fall (the benefits of disease prevention accrue gradually)
Worsens inequity (better quality exacerbates pre-existing provider shortage for disadvantaged)
Upstream Health Protection (with Leadership)
Consistent pattern of strong, sustained improvements in morbidity, mortality, cost, and equity
Takes time to generate significant effects (~10 years)
Works in three ways, all favoring the disadvantaged: (1) fewer upstream risks lower disease prevalence, which in turn (2) eases demand on scarce provider resources; and (3) reduces costs and improves health care access
Average unhealthy days per capita Health care spending per capita Health inequity index (morbidity)6
5.5
5
4.5
42000 2010 2020 2050
Protection
Coverage
Quality
2030 2040
Prototype Model Output
6,000
5,500
5,000
4,500
4,0002000 2050
Protection
Coverage
Quality
Prototype Model Output
2010 2020 2030 2040
0.2
0.15
0.1
0.05
02000 2050
Protection
Coverage
Quality
Prototype Model Output
2010 2020 2030 2040
Game-based “Wayfinding” Dialogues Combine Science and Social ChangeGame-based “Wayfinding” Dialogues Combine Science and Social Change
Potential champions need more than visionary direction. They want plausible pathways and visceral preparation.Potential champions need more than visionary direction. They want plausible pathways and visceral preparation.
Transforming All Dimensionsof the Health System
Transforming All Dimensionsof the Health System
Health
LivingConditions
Power toAct
Efforts to Fight Afflictions
Efforts to Fight Afflictions
Efforts to Improve Adverse Living Conditions
Efforts to Improve Adverse Living Conditions
Efforts to Build PowerEfforts to
Build Power
Equality of Agency
Equality ofOutcomes
Equality of Opportunities
Syndemic Orientation
Expanding Public Health ScienceExpanding Public Health Science“Public health imagination involves using science to expand the
boundaries of what is possible.”
-- Michael Resnick
“Public health imagination involves using science to expand the boundaries of what is possible.”
-- Michael Resnick
EpidemicOrientation
Problems Among
People inPlaces
Over Time
BoundaryCritique
Governing Dynamics
Ca
us
al
Ma
pp
ing
Plausible Futures
DynamicModeling
Navigational Freedoms
De
mo
cra
tic
Pu
bli
c W
ork
Milstein B. Hygeia's constellation: navigating health futures in a dynamic and democratic world. Atlanta, GA: Syndemics Prevention Network, Centers for Disease Control and Prevention; April 15, 2008.
For Further Informationhttp://www.cdc.gov/syndemics
For Further Informationhttp://www.cdc.gov/syndemics