jack homer, andrew jones, don seville homer consulting & sustainability institute joyce essien

The CDC’s Diabetes Systems Modeling Project: Developing a New Tool for Chronic

Disease Prevention and Control

Jack Homer, Andrew Jones, Don Seville Homer Consulting & Sustainability Institute

Joyce EssienRollins School of Public Health, Emory University

Bobby MilsteinDara Murphy

Centers for Disease Control and Prevention

International SD ConferenceOxford, U.K.July 27, 2004

Client and Issue

SAFER • HEALTHIER • PEOPLE ™

• Client: CDC’s Division of Diabetes Translation– Policy and Epidemiology Branches

• Issue: What are the pros and cons of “upstream” (prevention) and “downstream” (control) efforts?

Upstream Prevention and Protection----------------------------------Total 3%

Downstream Care and Management--------------------------------Total 97%

Public Health Efforts Today

Growth of Obesity and Diabetes in the U.S.

Fraction Population Obese and Fraction with Diabetes

0%

10%

20%

30%

40%

1960 1970 1980 1990 2000

Frac

pop

'n o

bese

0.0%

1.5%

3.0%

4.5%

6.0%

Frac

pop

'n w

ith d

iabe

tes

CDC -- NHANES; NHIS (adjusted in '97)

Obese

DiabetesDiagnosed

& with Diagnosed Diabetes

Dx

diab

etes

TIME Magazine Cover Story,

8 December 2003.

People withUndiagnosed,Uncomplicated

Diabetes

People withDiagnosed,

UncomplicatedDiabetes

People withDiagnosed,Complicated

Diabetes

DiagnosingUncomplicated

Diabetes

People withUndiagnosedPreDiabetes

People withDiagnosed

PreDiabetes

DiagnosingPreDiabetes

DevelopingComplications from

Undx diab

DevelopingDiabetes from Undx

PreD,People with

Undiagnosed,Complicated

Diabetes

DiagnosingComplicated

Diabetes

Dying from UndxComplications

People withNormal

GlycemicLevels

CaloricIntake

PhysicalActivity

ClinicalManagement of

PreDiabetes

Ability to SelfMonitor

MedicationAffordability

Clinical Managementof Diagnosed

Diabetes

Access toPreventive Health

Services

Testing forDiabetes

Testing forPreDiabetes

Obese Fraction ofthe Population

Risk forPreDiabetes

Control ofPreDiabetes

Control ofDiabetes

Detection ofComplicated

Diabetes

Detection ofUncomplicated

Diabetes

Detection ofPreDiabetes

Adoption ofHealthy Lifestyle

Model Structure

BMI/Obesity Clinical Management of Diagnosed PreD &

Diabetes

DownstreamUpstream

Base RunObesity Prevalence

0.5

0.4

0.3

0.2

0.11980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Diabetes Prevalence0.15

0.125

0.1

0.075

0.051980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Deaths per Complicated0.08

0.07

0.06

0.05

0.041980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Deaths per Population0.0035

0.003

0.0025

0.002

0.00151980 1990 2000 2010 2020 2030 2040 2050

Time (Year)


0.003

0.0025

0.002

0.00151980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Downstream-Only Intervention

Blue: Base run; Red: Clinical mgmt of diagnosed up from 66% to 90%

Base

Downstream


0.003

0.0025

0.002

0.00151980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Upstream-Only Intervention

Blue: Base run; Red: Clinical mgmt up from 66% to 90%;Green: Caloric intake down 4% (99 Kcal/day)

DownstreamUpstream

Base


0.003

0.0025

0.002

0.00151980 1990 2000 2010 2020 2030 2040 2050

Time (Year)

Mixed Intervention

Blue: Base run; Red: Clinical mgmt up from 66% to 90%;Green: Caloric intake down 4% (99 Kcal/day);Black: Clin mgmt up to 80% & Intake down 2.5% (62 Kcal/day)

Base

DownstreamUpstream

Mixed

Linking Insights to Action1. Cross-stakeholder model-based

learning laboratories2. Analyzing the effectiveness of goal-

setting

Diagnosed Prevalence Fraction Relative to 2000 Value1.5

1.25

1

0.75

0.51990 1995 2000 2005 2010

Time (Year)

No progress +24%+14%

Meet onset goal(-29%)

Goals, Actual Performance, and Model Runs

2010 prevalence goal -38%

2000 prevalence goal -11%

+33%

“It felt like we flunked”

Prevalence *

Deaths

Small outflow, people can live for decades with the disease

Chronic DiseaseLevel rises until the inflow is less than the outflow

Onset *

Large inflow, double the outflow

* Diagnosed

“It is expected that if you do a good job, things ought to go

down.” – Diabetes Branch Leader

Prevalence

Acute Infectious Disease

Onset

Large inflow, but usually fast to reduce

Level falls as inflow quickly drops below outflow

Large outflow via recovery or death

Recovery Deaths

Think measles, flu or SARS

Three of the Resulting Actions

• Head of the division amended the 38% goal for prevalence to say that they are not aiming for a decline

• Clients now broadcasting an improved mental model for chronic disease

• Epidemiology and Policy leaders co-writing their first paper on using SD to improve internal consistency of goals

Bridging the SD/Audience Divide

• Sometimes a stock/flow-dominated model is what client needs

• Help client to identify and communicate the shortcomings of old mental models and benefits of the new

Supplementary Materials


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

CaloricIntake

PhysicalActivity


PreDiabetes




Diabetes


Services

Testing forDiabetes



Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes



Possible Areas for Intervention

BMI/Obesity Clinical Management of Diagnosed PreD &

Diabetes

Now CDC is Exploring More “Upstream” Interventions


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes


Deaths from complications

Diabetesonset

Complicationsonset

CaloricIntakeMean body

weight/BMI

Basal metabolic

rate

Caloricbalance Physical

Activity

ObeseFraction of Population


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes


Past Focus of Interventions into the Diabetes System Has Been “Downstream”


Diabetesonset

Complicationsonset

Bridging the Divide

1. Learn client’s analytic needs and turn-ons

2. “Go Native” in language and form

3. Help client to identify and communicate shortcomings of old mental models

Missing Goals Was Attributed as Failure

• “The current epidemiology of type 2 diabetes could be used to argue that the [National Diabetes Prevention and Control Program] has been a monumental failure… [One] hypothesis, that this is a little known government bureaucracy spending large sums of money without achieving the desired goals, cannot be refuted based on the information at hand.”

• Anonymous reviewer of paper by client

What We Did

• Used model to check realism of objectives

• We “Went Native” in language and form– Fit to their variable names– Results in table format, not graphs

We’ll Focus On the Two Stocks that, Together, are “Diagnosed Prevalence”


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes



Diabetesonset

Complicationsonset

CaloricIntakeMean body

weight/BMI

Basal metabolic

rate


Activity


The Public Health Challenge of Chronic Disease

• Leading cause of illness, disability, and death in developed countries– 70-80% of U.S. health care claims

– Over 50% of U.S. adult population have at least one chronic disease; 25% have two or more

• A systems approach is needed – Dynamic complexity: Long delays of disease progression

– Need SD for better goal-setting, priorities, coordination

– Need to understand over-time impacts of “upstream” and “downstream” interventions

Safer,HealthierPeople

VulnerablePeople

AfflictedPeople withoutComplications

AfflictedPeople with

Complications

Primaryprevention

Secondaryprevention

Tertiaryprevention

Generalprotection

Targetedprotection

Society's Health Response

Dying fromcomplications

SAFER • HEALTHIER • PEOPLE ™

Chronic Disease Interventions, and the CDC’s Stated Mission

“CDC: Enhancing Health Protection!” – Dr. Julie Gerberding, Director

“UPSTREAM” “DOWNSTREAM”

Diabetes Stocks & Flows


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes



Diabetesonset

Complicationsonset

CaloricIntake

Mean body weight/BMI

Basal metabolic rate


Activity


In 2000, They Set HP 2010 GoalsBaseline~2000

HP 2010 Target

Percent Change

Reduce Prevalence of Diagnosed Diabetes

(5-3)

40 per 1,000 25 -38%

Reduce Diabetes–related Deaths

Among Diagnosed (5-6)

8.8 per 1,000 7.8 -11%

Increase Diabetes Diagnosis (5-4) 68% 80%

+12Percentpoints

“It is expected that if you do a good job, things ought to go down.”

We Looked at the Stock/Flow Internal Consistency of the Objectives

It is physically impossible for the diagnosed

prevalence to fall at all, much less 38%

If the diagnosis flow rises

sufficient to boost the fraction

diagnosed by 12 points

And if the deaths flow drops 11%

People withNormal

GlycemicLevels

People withUndiagnosed

DiabetesDiabetesonset

People withDiagnosedDiabetes

Diagnosisrate

Deaths fromcomplications

We Looked at the Stock/Flow Internal Consistency of the Objectives

People withNormal

GlycemicLevels


Diabetes


Diabetesonset

Diagnosisrate


It is physically impossible for the diagnosed

prevalence to fall at all, much less 38%

If the diagnosis flow rises

sufficient to boost the fraction

diagnosed by 12 points

And if the deaths flow drops 11%

Unexpected Behavior from the ModelDiagnosed Prevalence Fraction Relative to 2000 Value

1.5

1.25

1

0.75

0.51990 1995 2000 2005 2010

Time (Year)

No continued progress

Meet prevalence goal -38%

+24%+13%

Meet onset goal


– Diabetes Branch Leader

Exploring the Existing Mental Model: Infectious Disease

“Even here in chronic disease, we are still living

with the model that you find the patients, you give them a shot, and they recover.”

People withNormal Health


Infectious Disease


Infectious Disease

Onset

Diagnosis rate


Interventions in infectious diseases boost an important

outflow: recovery

Recovery

Diagnosed Prevalence Fraction Relative to 2000 Value1.5

1.25

1

0.75

0.51990 1995 2000 2005 2010

Time (Year)

No progress +24%Meet detection goal +42%

+13%Meet onset goal

(-29%)

Unexpected Behavior from the Model

Meet prevalence goal -38%



Then 2000, they set goals for 2010, including Diagnosed Prevalence

People withNormal

GlycemicLevels


Diabetes


Diabetesonset

Diagnosisrate


Yet another aimed for the deaths flow to drop 11%

Another aimed for a 29%

reduction in the onset rate

One goal aimed to boost the

fraction diagnosed by 12

points

Can they meet the goal of a 38% drop in diagnosed

prevalence?

Exploring the Existing Mental Model: Acute Infectious Disease

People withNormal Health


Infectious Disease


Infectious Disease

Onset

Diagnosis rate


2. Those who don’t die, recover naturally and

quickly

Recovery

Think measles, flu or SARS

1. People who die, die

soon

3. Quarantines and vaccinations can cut onset

significantly

When you cut the inflow to a bathtub with two big

drains, the water level falls quickly

In 2000, They Set HP 2010 Goals

• In 2000, they set a goal of 38% reduction in diagnosed prevalence by 2010

• At same time, other goals for diagnosis and care– Fraction diagnosed up 12 percentage points– Reduce diabetes–related deaths among diagnosed by

11%



History of Healthy People 2000• In 1990, stakeholders set “Healthy People 2000”

objectives

• Goal for diagnosed prevalence was an 11% reduction between 1990 and 2000

• During 90s, significant advances

• Combined effect by 2000 was 33% increase in diagnosed prevalence fraction

• “It felt like we flunked” – Program person

-11%

+33%


Diabetes




Diabetes


Diabetes



PreDiabetes



Undx diab


PreD,People with


Diabetes


Diabetes


People withNormal

GlycemicLevels

CaloricIntake

PhysicalActivity


PreDiabetes




Diabetes


Services

Testing forDiabetes



Risk forPreDiabetes


Control ofDiabetes


Diabetes


Diabetes



Drivers Calibrated Using National Survey Data

BMI/Obesity

20%

81%

85%

84%86%60%

480 Kcal/day

2,465 Kcal/day

66%

(Values shown are estimates for 2004.)

66%

Clinical Management of Diagnosed PreD &

Diabetes

jack homer, andrew jones, don seville homer consulting & sustainability institute joyce essien

Documents

clinical mgmt

base run red

chronic disease prevention

improved mental model

disease control

clin mgmt

caloric intake

stockflowdominated model