using microsimulation to inform targeted cardiovascular disease prevention policy dehmer

USING

MICROSIMULATION TO

INFORM TARGETED

CARDIOVASCULAR

DISEASE PREVENTION

POLICY

STEVEN DEHMER, PHD

RESEARCH FELLOW, HEALTHPARTNERS RESEARCH

FOUNDATION

HMORN 2012 Conference, Seattle WAMonday, April 30th

Presentation Outline

1) Brief Project Background

2) Description of the CVD Prevention Policy Model

3) Brief Description of Results

Project Background

Context:

Need to identify priority areas for prevention (NCPP)

1) Evidence driven

2) Consistent and comparable

3) Account for disparities and population-specific effects

Purpose:

a) Assess USPSTF recommended cardiovascular clinical services

b) Assess cardiovascular impacts of other clinical and community services

Project Background

Cardiovascular Clinical Preventive Services (USPSTF):

1) Screening for lipid disorders in adults Men (35+ or 20-35 at ↑ risk); Women (20+ at ↑ risk)

2) Hypertension screening for adults (18 and older)

3) Aspirin counseling for primary prevention of CVD Men ages 45-79 with increased risk from myocardial infarction

Women ages 55-79 with increased risk from stroke

Balance potential CVD benefits with gastrointestinal bleeding risks

CVD Prevention Policy Model

Design Overview:

“Microsimulation” model: start with an individual and predict lifetime progression of health status and outcomes

Simulations of many individuals can be aggregated to estimate population-wide impacts

Interventions or counterfactuals tested as if in a randomized controlled trial (here: same people and all else held equal)

Key benefit of complex design: sub-population effects for informing targeted policy


Design Overview:

Demographic characteristics: Age 20 to 100

Sex: Male, Female

Race/ethnicity: Non-Hispanic white

Non-Hispanic black/African American

Hispanic/Mexican American

“Other”

Health characteristics (change as an individual ages): Body mass index (BMI)

Cholesterol: LDL, HDL

Systolic blood pressure (SBP)

Smoking status

Disease status


Design Overview:

Cardiovascular disease events: Myocardial infarction (MI)

Ischemic stroke (IS)

Hemorrhagic stroke (HS)

Congestive heart failure (CHF)

Angina pectoris (AP)

Intermittent claudication (IC)

Related disease: Diabetes

Mortality: CVD related death

Non-CVD death


Model Initialization:

NHANES (1999-2008)

• Sex

• Race/ethnicity

• HDL, LDL

• SBP

BRFSS (2009)

• BMI


Eligibility for Prevention:

USPSTF Recommendations:

1) Lipid screening

2) BP screening

3) Aspirin counseling

Delivery of untestedrecommendations set at contemporary rates (NHANES, 1999-2008)


Eligibility for Treatment:

Based on NationalClinical Guidelines:

• ATP III for lipids

• JNC-7 for hypertension

• USPSTF for aspirin


Treatment Effects:

Meta-analyses and literature reviews (evidence from major clinical trials)

• Lipid treatment with statinslowers LDL, raises HDL

• Hypertension treatment lowers SBP

• Aspirin treatment lowers MI risk in men, ischemic stroke risk in men; raises HS and GI bleeding risk in all


CVD Event Risk:

Customized 1yr risk equations estimated using Framingham Heart Study Data

• Includes original and offspring cohorts

• About 10,000 people

• Longitudinal design from 1950-2003

• Mostly white


Risk of Death:

CVD-death risk estimated using Framingham HeartStudy data

Death from other causes estimated using life tables (net of CVD mortality)


Progression of Risk Factors:

Estimated using a two-step process:

1) Determine if there is a change

2) Determine size of change

Cholesterol and BP changes from Framingham Heart Study data

Changes in BMI from BRFSS (2009)


Costs:

1) Costs of disease First-year and ongoing costs estimated from MEPS

(1999-2008)

2) Costs of screening/monitoring Clinic/lab fees from National Fee Analyzer (2005)

3) Costs of treatment Statin and antihypertensive treatment costs from

Express Scripts Drug Trend Report (2010)

Simulation Results

Evaluation of USPSTF Recommendations :

Preliminary estimates (2012):

1) Screening for lipid disorders in adults C/E: $50,000 per QALY CPB: 650,000 QALYs

2) Hypertension screening for adults C/E: $65,000 per QALY CPB: 500,000 QALYs

3) Aspirin counseling for primary prevention of CVD C/E: $100 saved per person CPB: 150,000 QALYs

Simulation Results:

Disparities

Total Men Women White Black Hispanic Other

Myocardial Infarction

29,301 38,200 20,091 28,234 33,931 29,864 27,745

Ischemic Stroke 18,247 17,292 19,235 17,838 20,388 18,370 17,188

Angina Pectoris 21,355 25,080 17,499 20,948 22,656 21,722 21,256

Congestive Heart Failure

29,381 29,404 29,357 27,684 35,004 30,892 28,656

Intermittent Claudication

10,498 12,204 8,732 10,232 12,200 10,200 10,182

CVD-related Death

38,055 42,758 33,187 37,293 41,653 38,167 37,133

Life Expectancy 78.96 76.02 82.01 79.06 78.58 78.96 78.93

Hypertension Reference Case, No Screening, Rates per 100k

Conclusion

Questions/Comments?

using microsimulation to inform targeted cardiovascular disease prevention policy dehmer

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