Effect of CostCost-Sharing on Screening
Mammography in Medicare Managed
Care Plans
Background
„
„
Amal Trivedi, MD, MPH
William Rakowski, PhD
John Ayanian, MD, MPP
„
„
CostCost-sharing affects nearly every American with
health insurance
Copayments reduce moral hazard to “overconsume”
overconsume”
health care with full insurance
May also reduce use of appropriate preventive care
Several wellwell-known studies of costcost-sharing have
excluded the elderly
2007 AcademyHealth Annual Research Meeting
Objectives
To determine the prevalence of mammography
costcost-sharing in Medicare health plans
To understand the impact of costcost-sharing on the
appropriate use of mammography
To assess effects of mammography costcost-sharing
on vulnerable population groups
Sources of Data
„
20012001-4 Medicare HEDIS data
„
20012001-4 Medicare enrollment file
„
20012001-4 CMS health plan benefit data
„
2004 Interstudy Competitive Edge database
Study Population
„
„
„
Included women age 6565-69 who had been
assessed for the HEDIS breast cancer screening
indicator
Excluded women who died during the
measurement year
Final study population: 366,475 women in 174
health plans
Variables
„
„
„
Independent variable: enrollment in a plan with
>$10 or >10% coinsurance for screening
mammography
Dependent variable: receipt of a biennial
screening mammogram
Covariates:
IndividualIndividual-level: race (black, white, other), zip code
level income and education, buybuy-in eligibility, year
„ PlanPlan-level: census region, model type, plan size, plan
age, taxtax- status
„
1
Analyses - Main Sample
„
„
„
Analyses - Subsample
Assessed characteristics of enrollees and breast
cancer screening rates in costcost-sharing and fullfullcoverage plans
Constructed multivariate regression models
adjusting for individual and plan covariates and
clustering by plan
Included interactions of costcost-sharing with
income, education, race and buybuy-in eligibility
„
Identified seven plans that changed from full coverage
to costcost-sharing
„
Performed a differencedifference-inin-difference analysis by
comparing longitudinal changes in screening compared
to 14 matched control plans
„
Plans matched based on:
„
„
„
Trends in Mammography CostCost-sharing
Year
# of plans
(N=174)
% of women in
costcost-sharing
plans
2001
3
0.5
2002
10
4.3
2003
11
4.8
2004
21
11.4
Census region
ProfitProfit-status
Model type
Characteristics of Enrollees in CostCost-Sharing
and Full Coverage Plans
Age (y)
Black (%)
Below Poverty (%)
College Attendance (%)
BuyBuy-in (%)
CostCost-Sharing
67.1
23
11
32
10
Full Coverage
67.1
10
9
35
7
Median copayment $20 (Range $13-$35)
5 plans charged 20% coinsurance
Screening Rate (%)
Breast Cancer Screening Rates in CostCostSharing and FullFull-coverage Plans
100
90
80
70
60
50
40
30
20
10
0
76.7
65.7
2002
Effect of CostCostsharing
78.2
77.5
70
69.7
2003
Cost-sharing
Adjusted Impact of CostCost-sharing on
Screening Mammography
Full coverage
2004
Unadjusted
-8.3%
Adjusted for SES,
plan characteristics,
and clustering by
plan
-7.2%
95% CI/p
-9.7%, -4.6%
P<0.001
* Cost-sharing had the largest effect on
mammography of any of the plan covariates in
the model
2
Mammography Rates in plans that instituted costcostsharing compared to matched controls
Adjusted Effect of CostCost-sharing by Income and Education
0.0%
2002
2004
Change
∆-∆
-2.0%
Adjusted
∆-∆
-4.0%
-4.7%
-6.0%
-8.0%
-8.3%
-5.5%
Low
Medium
High
-11.8%
Education
74.8%
Maintained
full coverage
71.9%
-7.5% -7.7%
-10.0%
-12.0%
Added costcostsharing
Income
P<0.001 for trends
Mammography Rates in 7 Plans that Instituted CostCostsharing in 2003 Compared to 14 Matched Control Plans
2002
2004
Change
Added
costcostsharing
74.8%
69.3%
-5.5%
Maintained
full
coverage
71.9%
75.3%
+3.4%
Mammography Rates in 7 Plans that Instituted CostCostsharing in 2003 Compared to 14 Matched Control Plans
2002
2004
Change ∆-∆
Added
costcostsharing
74.8%
69.3%
-5.5%
Maintained
full
coverage
71.9%
75.3%
+3.4%
Mammography Rates in 7 Plans that Instituted CostCostsharing in 2003 Compared to 14 Matched Control Plans
2002
2004
Change
∆-∆
74.8%
69.3%
-5.5%
-8.9% -8.8%
Adj.
∆-∆
Maintained
full coverage
(-4.0, -13.6%)
P=0.002
71.9%
75.3%
+3.4%
-8.9%
Limitations
„
„
Added costcostsharing
Adj.
∆-∆
„
„
„
Women not randomly assigned to costcost-sharing
plans
Unable to analyze differential impacts of specific
copayment amounts
Lacked information on rescreening
ZipZip-code proxies for income and education
Limited to Medicare managed care
3
Conclusions
„
„
„
Copayments of >$10 or coinsurance of >10%
associated with lower rates of breast cancer
screening
CostCost-sharing disproportionately affects
vulnerable populations
Prevalence of costcost-sharing is dramatically
increasing in Medicare managed care
Implications
„
„
„
CostCost-sharing should be tailored to the
underlying value of the health service
Eliminating copayments may increase adherence
to appropriate preventive care
Important implications for Medicare FFS, where
enrollees without supplemental coverage face
20% coinsurance
Moral Hazard
“If your office gives you and your coco-workers all the
free Pepsi you want—
want—if your employer, in effect, offers
universal Pepsi insurance—
insurance—you’
you’ll drink more Pepsi than
you would have otherwise.”
otherwise.”
- Malcolm Gladwell
“The Myth of Moral Hazard”
Hazard”, in
The New Yorker, August 29, 2005
Study Population
Health Plan Characteristics of Enrollees in
CostCost-Sharing and Full Coverage Plans
24,468,528 observations in HEDIS data from 2001-4
Matched to Enrollment File (97% match rate)
23,656,038 observations
Excluded males, enrollees not between 65-69,
persons who died in measurement year, and
observations from 2001
2,189,983 observations from 178 plans from 2002-4
Linked to Interstudy database; excluded four
plans where Interstudy data not available
2,143,556 observations from 174 plans
CostCost-sharing
Full coverage
South
36%
16%
West
21%
41%
Staff/Group
Model
ForFor-profit
7%
18%
72%
56%
Excluded enrollees who were not assessed for
HEDIS mammography measure
550,082 observations (366,475 enrollees)
4
Adjusted Negative Effect of CostCost-sharing by Race and
Medicaid Eligibility
0.0%
-2.0%
Yes
No
White
Black
-3.7%
-4.0%
-6.0%
-6.8%
-7.8%
-8.0%
-10.0%
-12.0%
-14.0%
-13.4%
Medicaid
Race
P<0.001 for trends
5