Implications of the Affordable Care Act for Use of VA 

Primary Care: Lessons from the Massachusetts Health 

Reform

Edwin S. Wong, PhD

VA Puget Sound HSR&D 

HERC Cyberseminar

June 18, 2014
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Acknowledgements 

• Sources of funding

– VA Career Development Award (Wong, CDA 13-024)

• Collaborators

– Matthew Maciejewski, PhD (VA Durham)

– Paul Hebert, PhD (VA Puget Sound)

– Adam Batten (VA Puget Sound)

– Chuan-Fen Liu, PhD (VA Puget Sound)

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Poll 

• Are you affiliated with VA?

– Yes

– No

3 
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Poll 

• What is your primary professional role?

– Researcher

– Clinician

– Operations 

– Hospital administration

– Student/Fellow

– Other

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Massachusetts Health Care Reform

• April 2006 law enacting major health reform

• Key components:

– Individual mandate – Requirement that everyone in Massachusetts 

have health insurance coverage

– Expansion of health insurance market

• Establishment of Commonwealth Health Insurance Connector

• Subsidies to low income households

– Medicaid expansion

• Increased enrollment caps

• Higher provider payment rates

• VA not directly affected by health reform law

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1Holahan and Blumberg (2006). Health Affairs 25(6). 
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• Lower rate of uninsurance1 

– 6.6% point decrease among non-elderly adults

• Greater private insurance enrollment1 

– 3.1% point increase in employer-sponsored coverage

• Greater Medicaid enrollment2 

– 19.4% point increase among low-income parents 

Health Care Reform Associated with:

2Sonier J, et al. (2013). Health Affairs 32(7). 

1Long SK, et al. (2009). American Economic Review 99(2). 
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• Greater use of primary care3 

– 3% point increase in probability of having a primary care visit

• Greater use of preventative care4 

– 5.5% increase in colonoscopy rates

• Longer average wait times for appointment with an internist5

– 33 days in 2006 to 50 days in 2009

• Limited data examining potential impact on Veterans and VA

Health Care Reform Associated with:

5Ku L, et al. (2009). Kaiser Family Foundation. 

4Van Der Wees, et al. (2013). Milbank Quarterly 91(4). 

3Miller (2012). Inquiry 49(4). 
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• Largest integrated health care system in the U.S. 

• Safety net provider for many Veterans

• Eligibility Criteria:

– Service-connected disabilities

– Low income

– Special circumstances (i.e. Purple Heart Awardee) 

Veterans Affairs Health Care System (VA)
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• Outpatient copayments:

– Primary care ($15) 

– Specialty care ($50)

• Exempt from copayments if:

– ≥ 50% service connected disability

– Income below national thresholds

VA Health Care System
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Veterans Have Many Health Options
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Veterans Have Many Health Options
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Dual VA and Non-VA Use is Common
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Conceptual Model: Stock and Flow

• Example: Household wealth

– Stock of wealth at a given point in time

– Inflows: Increase wealth stock

– Outflows: Decrease wealth stock

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Wealth Stock
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Wealth Stock

Job Income Dividend Income Interest Payments

Inflows
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Wealth Stock

Job Income Dividend Income Interest Payments

Rent Food and Dining Health Care Costs

Inflows

Outflows
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Applying Stock and Flow Model to VA Use

• Stock: Population of VA users

• Inflows: New VA users

• Outflows: 

– Veterans no longer using VA

– Veterans who die

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VA Users

New Enrollees Old Enrollees Recently Using VA

Veterans no longer using VA Deceased Veterans

Inflows

Outflows
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• Changes in VA primary care use due to enrollment changes

• Three major components of health reform:

1. Individual Mandate (inflow)

2. Expansion of health insurance market (outflow) 

3. Medicaid Expansion (outflow) 

How Health Care Reform Affects Veterans
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Composition of VA Population May Change

• VA primary care utilization may change even if health reform 

does not change net VA enrollment

• Characteristics of VA user “stock” following health reform may 

change 

– Changes in health need among remaining VA users

– Changes in market for non-VA care

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Changes in Veterans’ Health Need

• Self-selection among Veterans who remain in VA

– Copayment-exempt status

– High reliance on VA care

• Veterans who leave VA

– Less reliant on VA care

• Removing less reliant Veterans increases average VA use

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Changes in Veterans’ Health Need

• Younger previously uninsured Veterans

• Veterans enrolling in non-VA programs who would enroll in VA 

in the absence of health care reform

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Changes in Market for Non-VA Care

• Health reform externalities for dual users of VA and non-VA

care

– Increasing non-Veterans’ access to community providers may result in 

difficulty obtaining appointments for Veterans

– Supply constraints in short run

– Continued users of VA may shift primary care to VA

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Goal of this research

• To examine whether health care reform in 

Massachusetts was associated with changes in VA 

primary care use.

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• VA Administrative Databases

– Corporate Data Warehouse

– Outpatient Care Files

• Fee-for-Service Medicare Data

– Carrier File

– Outpatient File

• Area Health Resource File

• RUCA ZIP Code files

Data
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• Natural experiment

– Massachusetts Veterans subject to health reform starting in June 2006

– Exogenous change in health policy

Study Design
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• Treatment and control group determined by exposure to 

health reform

Study Design

Group State of Residence

Treatment Group Veterans residing in Massachusetts

Control Group Veterans residing in all other New 

England States

(Connecticut, Maine, New 

Hampshire, Rhode Island, Vermont)
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Study Timeline

Oct 2004

Massachusetts Veterans 

Subject to Reform

Jun 2006

Not Subject to Reform

Other New England Veterans 

Not Subject to Reform

Sep 2008
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• 262,335 unique Veterans present in the Primary Care 

Management Module (PCMM) and residing in New England

– Reflects nearly all active VA primary care users

– Present in PCMM if any VA use within 24 months

• Exclusions: 

– Veterans who lived in both Massachusetts and other New England 

states (N=3,870)

– Veterans missing covariate data (N=2,070)

• Final Study Sample: 256,395 VA users present in PCMM 

during period FY2005-Q1 to FY2008-Q4

Study Sample
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Study Sample

• Unit of analysis: Repeated Veteran-quarter observations

• Analyses stratified by age group (under 65 and 65+) to 

account for Medicare eligibility.

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• Count of quarterly primary care visits in:

– VA – defined by stop codes

– Fee-for-service Medicare – calculated using algorithm based on CPT 

and provider specialty codes1 

Outcomes

1Burgess JF, et al. (2011). Health Econ 20(2). 
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• Difference-in-difference (DID) approach

– Account for common trends among all Veterans

– Calculate pre-post change in primary care use for: 

• Massachusetts Veterans 

• Other New England Veterans

– Subtract pre-post changes 

Statistical Analysis
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• Fixed effects negative binomial regression 

– Mundlak correction 

– Account for time-invariant unobserved patient variables affecting 

primary care use

• Control Variables:

– Individual demographics

– Health status and comorbidity

– Prior VA use

– Economic conditions

– Seasonality 

– County-level characteristics

Statistical Analysis
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Descriptive Statistics – Under 65 

Massachusetts VA Users

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Variable Baseline 

 (FY2005-Q1)

Study End

(FY2008-Q4)

Age (mean/SD) 53.2 (9.3) 52.2 (11.3)

Male 93.3% 92.5% 

Exempt from Copayments 79.9% 85.2% 

Race - White 66.8% 66.9% 

Race - Black 6.1% 6.1% 

Elixhauser Score (mean/SD) 1.7 (1.5) 1.6 (1.6)

Miles to Nearest VA (mean/SD) 6.2 (5.1) 6.5 (5.2)

Local Unemployment Rate (mean/SD) 5.5 (0.9) 6.0 (0.9)

# VA Users 19,093 23,148 
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Descriptive Statistics – Under 65 Other New 

England VA Users

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Variable Baseline 

 (FY2005-Q1)

Study End

(FY2008-Q4)

Age (mean/SD) 53.6 (9.1) 53.1 (10.8)

Male 92.8% 92.3% 

Exempt from Copayments 74.8% 81.3% 

Race - White 72.6% 73.3% 

Race - Black 5.0% 5.9% 

Elixhauser Score (mean/SD) 1.7 (1.6) 1.6 (1.6)

Miles to Nearest VA (mean/SD) 12.4 (10.2) 12.0 (9.8)

Local Unemployment Rate (mean/SD) 5.5 (1.3) 6.5 (1.5)

# VA Users 26,434 32,392 
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Descriptive Statistics – Age 65+ 

Massachusetts VA Users

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Variable Baseline 

 (FY2005-Q1)

Study End

(FY2008-Q4)

Age (mean/SD) 76.9 (6.4) 77.9 (6.9)

Male 97.5% 97.5% 

Exempt from Copayments 64.9% 68.3% 

Race - White 95.5% 95.6% 

Race - Black 2.8% 2.6% 

Elixhauser Score (mean/SD) 1.8 (1.6) 1.6 (1.6)

Miles to Nearest VA (mean/SD) 6.6 (4.9) 6.8 (5.0)

Local Unemployment Rate (mean/SD) 5.4 (1.0) 6.0 (0.9)

# VA Users 37,257 37,175 
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Descriptive Statistics – Age 65+ Other New 

England VA Users

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Variable Baseline 

 (FY2005-Q1)

Study End

(FY2008-Q4)

Age (mean/SD) 76.5 (6.3) 77.2 (6.9)

Male 97.9% 97.9% 

Exempt from Copayments 53.8% 56.9% 

Race - White 96.8% 96.4% 

Race - Black 2.0% 2.3% 

Elixhauser Score (mean/SD) 1.8 (1.5) 1.6 (1.6)

Miles to Nearest VA (mean/SD) 11.1 (9.1) 11.1 (8.7)

Local Unemployment Rate (mean/SD) 5.4 (1.1) 6.4 (1.5)

# VA Users 45,769 47,452 
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# Active VA Users by Group

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Difference in Enrollment Rate Decreasing

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User Rate = # of VA users / # of all Veterans in group
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Total Primary Use Increasing for Under 65 

VA Users

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Total Primary Use for Age 65+ VA Users

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Rate of Primary Care Use for Under 65 VA 

Users

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Visit Rate = # of VA Primary Care Visits / # VA Users
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Increasing Differences in Visit Rates

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Visit Rate = # of VA Primary Care Visits / # VA Users
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Rate of Primary Care Use for Age 65+ VA 

Users

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Visit Rate = # of VA Primary Care Visits / # VA Users
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Increasing Differences in Visit Rates

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Visit Rate = # of VA Primary Care Visits / # VA Users
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Health Reform Associations – Under 65 VA 

Users

Net Effect P-Value

All Under 65 VA Users

0.022 visits < 0.001 

Continuous Enrollees

0.036 visits < 0.001 

* Difference-in-difference estimates after adjusting 

for Veteran covariates and fixed effects

** Net effects reflect change in quarterly PC 

visits attributable to health reform
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Health Reform Associations – Age 65+ VA 

Users

Net Effect P-Value

All Age 65+ VA Users

0.022 visits < 0.001 

Continuous Enrollees

0.021 visits < 0.001 

FFS Medicare Visits

-0.031 visits < 0.001

*Difference-in-difference estimates after adjusting 

for Veteran covariates and fixed effects

** Net effects reflect change in quarterly PC 

visits attributable to health reform 
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Extrapolating DID Estimates

• Health care reform associated with a 0.022 increase in perquarter VA visits

– ~ 1 additional visit per 45 VA users

– 89,089 VA users residing in Massachusetts in FY2008-Q4

– 1,980 additional primary care visits attributable to health reform

– ~ 160 additional visits per week

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Limitations

• Veterans living in Massachusetts may be legal residents of 

another state

• Only VA and fee-for-service Medicare primary care use 

measured

• Generalization of results should consider unique 

characteristics of New England Veterans

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Policy Implications

• Key ACA components also in Massachusetts Health Care 

Reform

• Results may inform changes in VA use in the post-ACA era

– Health reform may slow the growth in VA enrollment by providing 

other health care options

– Greater use of primary care among Veterans who remain in VA

– VA an important source of care for age 65+ Veterans likely due to 

higher overall demand among non-VA providers

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Thank You!