Presentation by Marguerite Burns at the 2015 APPAM Fall Research Conference on November 12, 2015, in Miami, FL.

1. The Effects of Expanding Public
Insurance to Childless Adults
Marguerite Burns, Ph.D.
University of Wisconsin-Madison
APPAM Fall Research Conference
November 12, 2015

2. 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

3. What Do We Know About the Effects on Use
of Care of Expanding Medicaid to Childless
Adult Populations?

4. 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

5. 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. 6

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

9. Marshfield
Milwaukee County

10. 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

11. 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

12. 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

13. 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

14. 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)

15. Method 1: Pre-Post Comparison
12-months of
pre-enrollment
utilization
12-months of
post-enrollment
utilization
Auto-enrollment into BC+ Core

16. Method 2: Regression Discontinuity
October 9, 2009
Last Individuals
enrolled
First individuals
placed on the
waitlist

17. Data: Wisconsin Medicaid

18. Data: Marshfield Clinic

19. Outcomes
Outpatient Visits
Emergency
Department Visits
Hospitalizations

20. Results from Milwaukee County

22. 40% Increase No Change 140% Increase

23. Results from Marshfield Area

24. Summary of Main Results
Any
Outpa*ent Preven*ve
Mental
Health or
Substance
Abuse 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 0.081
Notes: All results es,mated at a bandwidth of 14 days excluding one week prior to and following
the closing date.

25. Outpatient Visits
0246
Avg.NumberofOutpatientVisits
-20 -10 0 10 20
Days from Oct 5th (left) or Oct 14th (right)
Panel A. Outpatient

26. Preventive Care Visits
0.2.4.6.8
Avg.NumberofPreventiveCareVisits
-20 -10 0 10 20
Days from Oct 5th (left) or Oct 14th (right)
Panel B. Preventive Care

27. Mental Health or Substance Use
0.511.52
Avg.NumberofMHSUDVisits
-20 -10 0 10 20
Days from Oct 5th (left) or Oct 14th (right)
Panel C. Mental Health or Substance Abuse

28. ED Visits
0.1.2.3.4
Avg.NumberofEmergencyVisits
-20 -10 0 10 20
Days from Oct 5th (left) or Oct 14th (right)
Panel D. Emergency

29. Inpatient Visits
0.05.1.15
Avg.NumberofInpatientVisits
-20 -10 0 10 20
Days from Oct 5th (left) or Oct 14th (right)
Panel E. Inpatient

30. 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

31. 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

32. Extra Slides

33. 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 −−

34. 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%

35. 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 1011121314151617181920212223242526272829
Coefficientand95%CI
Bandwidth in Days
Panel E. Inpatient

36. 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 1011121314151617181920212223242526272829
Coefficientand95%CI
Bandwidth in Days
Panel D. Emergency