The Effects of Expanding Public Insurance to Childless Adults

Marguerite Burns, Ph.D. University of Wisconsin-Madison APPAM Fall Research Conference November 12, 2015

Acknowledgments

•  Co-authors Laura Dague, Ph.D., Texas A&M University Thomas DeLeire, Ph.D., Georgetown University Lindsey Leininger, Ph.D., Mathematica Policy Research, Inc. Gaston Palmucci, Ph.D., Fiscalia Nacional Economica Donna Friedsam, MPH, University of Wisconsin-Madison Kristen Voskuil, MA, University of Wisconsin-Madison John Schmelzer, Ph.D., Marshfield Clinic Mary Dorsch, RN, Marshfield Clinic

•  Funding

NIH NCATS Grant UL1TR000427 to the UW ICTR NIMH K01 092338 Robert Wood Johnson Foundation SHARE program WI Department of Health Services

What Do We Know About the Effects on Use of Care of Expanding Medicaid to Childless

Adult Populations?

Recent Studies

Massachusetts [Long and Dahlen, 2014] •  Increased likelihood of usual source of care

Oregon [Finkelstein et al.,2012; Baicker et al.,2013; Taubman et al., 2014]

•  Increased outpatient visits •  Mixed effects on ED use •  Initial increase in inpatient use that did not persist

Background: Prior to ACA Wisconsin sought to insure 98% of citizens

•  In 2008, program simplification and coverage

expansion to all children and low-income caretaker adults – BadgerCare Plus

•  In 2009 a coverage expansion to low-income childless adults – BC+ Core Plan •  Medicaid-like plan for uninsured adults w/out

dependent children with incomes < 200%FPL

6

How did the Core Plan for childless adults affect the use of health care?

Marshfield

Milwaukee County

Poor individuals in Milwaukee County • 9,619 prior users of the county safety net system who

were automatically enrolled on 1/1/09 Low-income individuals in Marshfield Clinic’s 28-county service area in central & northern WI

• Prior users of Marshfield Clinic safety net system

Two Populations

The Challenge in Studying the Effect of Health Insurance on Utilization

Participation or enrollment is a choice

vs. Attempt to find quasi-random changes in enrollment into public insurance

BC+ Core Plan Auto-Enrollment

GAMP BC+ Core Plan

January 1, 2009

Indigent care program for poor uninsured adults in Milwaukee County

12,941 individuals were auto-enrolled into BC+ Core Plan

BC+ Core Plan Enrollment Freeze

BC+ Core Waitlist

October 9, 2009

Statewide open enrollment begins for childless adults with incomes below 200% FPL.

Enrollment suddenly closed. Subsequent eligible applicants placed on a waitlist.

July 1, 2009

Our approach: Quasi-experimental design

Examine two populations 1.  Poor individuals who were automatically

enrolled into BC Core on January 1, 2009 (GAMP population, Milwaukee County)

2.  Low-income individuals who applied around

the time the enrollment cap was imposed (Marshfield Clinic)

Method 1: Pre-Post Comparison

12-months of pre-enrollment utilization

12-months of post-enrollment utilization

Auto-enrollment into BC+ Core

Method 2: Regression Discontinuity

October 9, 2009

Last Individuals enrolled

First individuals placed on the waitlist

Data: Wisconsin Medicaid

Data: Marshfield Clinic

Outcomes

Outpatient Visits

Emergency Department Visits

Hospitalizations

Results from Milwaukee County

40% Increase No Change 140% Increase

Results from Marshfield Area

Summary of Main Results

AnyOutpa*ent Preven*ve

MentalHealthorSubstanceAbuse Emergency Inpa*ent

Baseline 2.783 0.275 0.297 0.056 0.034

Coef 1.076 0.256 -0.064 0.060 0.042

P-Value 0.026 0.000 0.655 0.086 0.081Notes:Allresultses,matedatabandwidthof14daysexcludingoneweekpriortoandfollowingtheclosingdate.

Outpatient Visits 0

24

6

Avg.

Num

ber o

f Out

patie

nt V

isits

-20 -10 0 10 20Days from Oct 5th (left) or Oct 14th (right)

Panel A. Outpatient

Preventive Care Visits 0

.2.4

.6.8

Avg.

Num

ber o

f Pre

vent

ive C

are

Visit

s

-20 -10 0 10 20Days from Oct 5th (left) or Oct 14th (right)

Panel B. Preventive Care

Mental Health or Substance Use 0

.51

1.5

2

Avg.

Num

ber o

f MHS

UD V

isits

-20 -10 0 10 20Days from Oct 5th (left) or Oct 14th (right)

Panel C. Mental Health or Substance Abuse

ED Visits 0

.1.2

.3.4

Avg.

Num

ber o

f Em

erge

ncy V

isits

-20 -10 0 10 20Days from Oct 5th (left) or Oct 14th (right)

Panel D. Emergency

Inpatient Visits 0

.05

.1.1

5

Avg.

Num

ber o

f Inp

atien

t Visi

ts

-20 -10 0 10 20Days from Oct 5th (left) or Oct 14th (right)

Panel E. Inpatient

Outpatient visits •  Increase in Milwaukee sample •  Increase in Marshfield sample

ED visits

•  Increase in Milwaukee sample •  No change in Marshfield sample

Hospitalizations •  Decrease in Milwaukee •  Increase in Marshfield sample

Differences don’t seem to be due to differences in enrollee case mix

Heterogeneous Impacts

The impacts likely depend on the characteristics of the area health system Growing numbers of studies with credible designs; need to begin to focus on representativeness, and be attentive to variable effects across & within states.

Conclusions

Extra Slides

Local Linear Regression For outcome Yi, date Xi cutoff date x0, threshold indicator Wi

where the weights are given by h is the bandwidth in days, and τ is the treatment effect of interest.

Sharp Regression Discontinuity

( ) ( ) iiiiii WxXWxXY εγτβα +−++−+= 00

0xXh i −−

Demographic Characteristics

Core Enrollees

(All)

Core Enrollees (Within 30

Days)

Waitlisted Applicants

(All)

Waitlisted Applicants (Within 30

Days)

Number of enrollees 4,280 658 3,262 351

Male 41% 44% 48% 45%

Age, years 43.78 41.00 39.91 39.84

Age<35 30% 39% 45% 44%

Age 35-54 43% 39% 37% 40%

Age 55 + 26% 22% 18% 16%

Inpatient Visits

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Coe

ffici

ent a

nd 9

5% C

I

Bandwidth in Days

Panel E. Inpatient

ED Visits

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Coe

ffici

ent a

nd 9

5% C

I

Bandwidth in Days

Panel D. Emergency