Does a Patchwork Approach to Health
Insurance Expansion Exacerbate
Public Insurance Drop-Out?
Benjamin D. Sommers, Ph.D.
Harvard University
AcademyHealth Annual Meeting
June 26, 2005
Background:
Children Without Health Insurance
* 8.4 million children (11.4%) in U.S. have no
health insurance
* Over 6 million uninsured children are
eligible for Medicaid/CHIP
* 1 in 8 children “drops out” of Medicaid/CHIP
annually – becoming uninsured, despite still
being eligible
Sources: Census Bureau 2004, Selden et al. 2004,
Sommers 2005
Conceptual Framework:
Why Do Kids Disenroll?
Parents must reenroll annually to prove
eligibility. Why might they not do so?
☑ Acquiring Other Health Insurance
☑ Loss of Eligibility
☑ ‘Drop-Out’: Uninsured & Still Eligible
- Only “drop-out” is a program failure.
Motivation & Objectives
* Incrementalism is the current approach to
health insurance expansion:
Does this exacerbate the drop-out problem?
Question 1: Do separate CHIP's (vs.
combined Mcaid/CHIP programs) fare
differently in retention?
Question 2: Does covering parents improve
the retention of children?
Is This A Problem?
Mom & Dad
need not
apply...
Is this
Medicaid,
CHIP, or
both?
Data & Methods
• Child & household data from the CPS
March Supplement (2000-2004), using
two-year linked samples
• Since 2001, CPS asks about CHIP
separately from Medicaid
• State-specific eligibility rules from the
National Governors Association
• State policies for Medicaid/CHIP from
state welfare offices and previous studies
Results:
Key Descriptive Statistics
• As of 2001, 17 states + D.C. ran
combined CHIP/Medicaid programs, and
33 ran separate CHIP's.
• 23% of CHIP kids had a parent in public
insurance, vs. 61% of Medicaid kids
• Roughly 2 million children switched
back & forth between Medicaid & CHIP
each year
• Drop-Out: CHIP 15.6% , Medicaid 12.5%
Effect of Combined vs. Separate
Medicaid/CHIP Program on Drop-Out
Unadjusted
Odds Ratio
for 'Combined'
95% CI:
Adjusted for
+
Demographics* Policies**
0.69
0.68
0.64
(0.51-0.92)
(0.49-0.93)
(0.43-0.95)
N = 6526
% Reduced Risk = 31%
* Adjusted for gender, age, race, parental education, family income, parental
& sibling insurance coverage, health status, urban residence, state & year.
** Adjusted for demographics + the following Medicaid policies: frequency of
renewal, face-to-face interview at renewal, presumptive eligibility, state
renewal outreach, 12-month continuous eligibility, monthly premium,
physician reimbursement rate, physician participation rate, MCO penetration,
spending per child, charity care availability, & state political ideology.
Effect of Family Coverage in Medicaid
on Drop-Out Among Children*
Variable
Parent in
Mcaid/CHIP
% Reduced Risk
Sibling in
Mcaid/CHIP
% Reduced Risk
Logistic
Odds Ratio
0.65
2-Stage IV Logistic**
Odds Ratio
0.19
(p<.01)
(p<.01)
28%
72%
0.60
0.74
(p<.01)
(p<.10)
32%
20%
n = 9020
NOTES:
* Adjusted for gender, age, race, parental education, family income,
number of children, health status, urban residence, state & year.
** Instrumented for parental and sibling Medicaid/CHIP coverage using
parental and sibling Medicaid/CHIP eligibility.
Limitations
• Correlational only, for the combined vs.
separate programs
• 12 month snapshots don’t let us see:
– How long children stay enrolled
– If drop-outs ever return to Medicaid
• Technical issues for CPS data:
– Medicaid /CHIP Undercount
– Monthly vs. Annual Income Data
– Attrition Bias
Policy Implications
Separate programs are administratively
costly (2 million kids switching annually)
and exacerbate drop-out
→ States should consider combining
Medicaid & CHIP, or at least streamline
transitions between programs.
Covering parents and kids separately
doesn’t make sense in terms of retention
→ Cover families, not individuals.
Acknowledgments
This research was conducted with the
support of a fellowship from the
National Science Foundation.
Many thanks to Joe Newhouse, David
Cutler, Kathy Swartz, and Melissa
Wachterman for excellent advice
throughout this project.