effect of cost-sharing on screening mammography in medicare managed care plans amal trivedi, md, mph...

Effect of Cost-Sharing on Effect of Cost-Sharing on Screening Mammography in Screening Mammography in

Medicare Managed Care Medicare Managed Care PlansPlans

Amal Trivedi, MD, MPHAmal Trivedi, MD, MPH

William Rakowski, PhDWilliam Rakowski, PhD

John Ayanian, MD, MPPJohn Ayanian, MD, MPP

2007 AcademyHealth Annual Research 2007 AcademyHealth Annual Research MeetingMeeting

BackgroundBackground

Cost-sharing affects nearly every Cost-sharing affects nearly every American with health insuranceAmerican with health insurance

Copayments reduce moral hazard to Copayments reduce moral hazard to “overconsume” health care with full “overconsume” health care with full insuranceinsurance

May also reduce use of appropriate May also reduce use of appropriate preventive carepreventive care

Several well-known studies of cost-Several well-known studies of cost-sharing have excluded the elderlysharing have excluded the elderly

ObjectivesObjectives

To determine the prevalence of To determine the prevalence of mammography cost-sharing in Medicare mammography cost-sharing in Medicare health planshealth plans

To understand the impact of cost-sharing To understand the impact of cost-sharing on the appropriate use of mammographyon the appropriate use of mammography

To assess effects of mammography cost-To assess effects of mammography cost-sharing on vulnerable population groupssharing on vulnerable population groups

Sources of DataSources of Data

2001-4 Medicare HEDIS data 2001-4 Medicare HEDIS data

2001-4 Medicare enrollment file2001-4 Medicare enrollment file

2001-4 CMS health plan benefit data2001-4 CMS health plan benefit data

2004 Interstudy Competitive Edge 2004 Interstudy Competitive Edge databasedatabase

Study PopulationStudy Population

Included women age 65-69 who had Included women age 65-69 who had been assessed for the HEDIS breast been assessed for the HEDIS breast cancer screening indicatorcancer screening indicator

Excluded women who died during Excluded women who died during the measurement yearthe measurement year

Final study population: 366,475 Final study population: 366,475 women in 174 health planswomen in 174 health plans

VariablesVariables

Independent variable: enrollment in a Independent variable: enrollment in a plan with >$10 or >10% coinsurance plan with >$10 or >10% coinsurance for screening mammographyfor screening mammography

Dependent variable: receipt of a Dependent variable: receipt of a biennial screening mammogrambiennial screening mammogram

Covariates:Covariates: Individual-level: race (black, white, Individual-level: race (black, white,

other), zip code level income and other), zip code level income and education, buy-in eligibility, yeareducation, buy-in eligibility, year

Plan-level: census region, model type, Plan-level: census region, model type, plan size, plan age, tax- status plan size, plan age, tax- status

Analyses - Main SampleAnalyses - Main Sample

Assessed characteristics of enrollees Assessed characteristics of enrollees and breast cancer screening rates in and breast cancer screening rates in cost-sharing and full-coverage planscost-sharing and full-coverage plans

Constructed multivariate regression Constructed multivariate regression models adjusting for individual and models adjusting for individual and plan covariates and clustering by planplan covariates and clustering by plan

Included interactions of cost-sharing Included interactions of cost-sharing with income, education, race and buy-with income, education, race and buy-in eligibilityin eligibility

Analyses - SubsampleAnalyses - Subsample Identified seven plans that changed from Identified seven plans that changed from

full coverage to cost-sharingfull coverage to cost-sharing

Performed a Performed a difference-in-difference difference-in-difference analysisanalysis by comparing longitudinal changes by comparing longitudinal changes in screening compared to 14 matched in screening compared to 14 matched control planscontrol plans

Plans matched based on:Plans matched based on: Census regionCensus region Profit-status Profit-status Model typeModel type

Trends in Mammography Cost-Trends in Mammography Cost-

sharingsharing

YearYear # of plans # of plans (N=174)(N=174)

% of women % of women in cost-in cost-sharing sharing plansplans

20012001 33 0.50.5

20022002 1010 4.34.3

20032003 1111 4.84.8

20042004 2121 11.411.4

Median copayment $20 (Range $13-$35)5 plans charged 20% coinsurance

Characteristics of Enrollees in Characteristics of Enrollees in Cost-Sharing and Full Coverage Cost-Sharing and Full Coverage

PlansPlans

Cost-Cost-SharingSharing

Full CoverageFull Coverage

Age (y)Age (y) 67.167.1 67.167.1

Black (%)Black (%) 2323 1010

Below Poverty (%)Below Poverty (%) 1111 99

College College Attendance (%)Attendance (%)

3232 3535

Buy-in (%)Buy-in (%) 1010 77

Breast Cancer Screening Rates in Breast Cancer Screening Rates in Cost-Sharing and Full-coverage Cost-Sharing and Full-coverage

PlansPlans

65.7 69.7 7076.7 77.5 78.2

0102030405060708090

100

2002 2003 2004

Scr

een

ing

Rat

e (%

)

Cost-sharing Full coverage

Adjusted Impact of Cost-Adjusted Impact of Cost-sharing on Screening sharing on Screening

MammographyMammographyEffect of Effect of

Cost-sharingCost-sharing 95% CI/p95% CI/p

UnadjustedUnadjusted -8.3%-8.3%Adjusted for Adjusted for SES, plan SES, plan characteristics, characteristics, and clustering and clustering by planby plan

-7.2%-7.2%-9.7%, --9.7%, -

4.6%4.6%

P<0.001P<0.001

* Cost-sharing had the largest effect on mammography of any of the plan covariates in the model

Adjusted Effect of Cost-sharing by Income Adjusted Effect of Cost-sharing by Income and Educationand Education

-11.8%

-8.3%

-4.7%

-7.5% -7.7%

-5.5%

-12.0%

-10.0%

-8.0%

-6.0%

-4.0%

-2.0%

0.0%

Education Income

LowMediumHigh

P<0.001 for trends

Mammography Rates in plans that Mammography Rates in plans that instituted cost-sharing compared to instituted cost-sharing compared to

matched controlsmatched controls

20022002 20042004 ChangChangee

∆∆-∆ -∆ AdjustAdjusted ∆-∆ ed ∆-∆

Added Added cost-cost-sharingsharing

74.8%74.8%

MaintainMaintained full ed full coveragecoverage

71.9%71.9%

Mammography Rates in 7 Plans that Mammography Rates in 7 Plans that Instituted Cost-sharing in 2003 Compared to Instituted Cost-sharing in 2003 Compared to

14 Matched Control Plans14 Matched Control Plans



74.8%74.8% 69.3%69.3% -5.5%-5.5%


71.9%71.9% 75.3%75.3% +3.4+3.4%%




∆∆-∆-∆ Adj. Adj.

∆∆-∆-∆


74.8%74.8% 69.3%69.3% -5.5%-5.5% -8.9%-8.9%


71.9%71.9% 75.3%75.3% +3.4+3.4%%




∆∆-∆-∆ Adj. Adj.

∆∆-∆-∆


74.8%74.8% 69.3%69.3% -5.5%-5.5% --8.98.9%%

-8.8%-8.8%(-4.0, -(-4.0, -13.6%)13.6%)

P=0.002P=0.002MaintainMaintained full ed full coveragecoverage

71.9%71.9% 75.3%75.3% +3.4%+3.4%

LimitationsLimitations

Women not randomly assigned to Women not randomly assigned to cost-sharing planscost-sharing plans

Unable to analyze differential impacts Unable to analyze differential impacts of specific copayment amountsof specific copayment amounts

Lacked information on rescreeningLacked information on rescreening Zip-code proxies for income and Zip-code proxies for income and

educationeducation Limited to Medicare managed careLimited to Medicare managed care

ConclusionsConclusions

Copayments of >$10 or coinsurance Copayments of >$10 or coinsurance of >10% associated with lower rates of >10% associated with lower rates of breast cancer screeningof breast cancer screening

Cost-sharing disproportionately Cost-sharing disproportionately affects vulnerable populationsaffects vulnerable populations

Prevalence of cost-sharing is Prevalence of cost-sharing is dramatically increasing in Medicare dramatically increasing in Medicare managed caremanaged care

ImplicationsImplications

Cost-sharing should be tailored to the Cost-sharing should be tailored to the underlying value of the health serviceunderlying value of the health service

Eliminating copayments may increase Eliminating copayments may increase adherence to appropriate preventive adherence to appropriate preventive care care

Important implications for Medicare Important implications for Medicare FFS, where enrollees without FFS, where enrollees without supplemental coverage face 20% supplemental coverage face 20% coinsurancecoinsurance

Moral HazardMoral Hazard

“ “If your office gives you and your co-workers If your office gives you and your co-workers all the free Pepsi you want—if your employer, all the free Pepsi you want—if your employer, in effect, offers universal Pepsi insurance—in effect, offers universal Pepsi insurance—you’ll drink more Pepsi than you would have you’ll drink more Pepsi than you would have otherwise.”otherwise.”

- Malcolm Gladwell- Malcolm Gladwell

““The Myth of Moral Hazard”, inThe Myth of Moral Hazard”, in

The New Yorker, August 29, The New Yorker, August 29, 20052005

Study PopulationStudy Population24,468,528 observations in HEDIS data from 2001-4

Matched to Enrollment File (97% match rate)

23,656,038 observations

2,189,983 observations from 178 plans from 2002-4

Excluded males, enrollees not between 65-69, persons who died in measurement year, and observations from 2001

2,143,556 observations from 174 plans

Linked to Interstudy database; excluded four plans where Interstudy data not available

550,082 observations (366,475 enrollees)

Excluded enrollees who were not assessed for HEDIS mammography measure

Health Plan Characteristics of Health Plan Characteristics of Enrollees in Cost-Sharing and Full Enrollees in Cost-Sharing and Full

Coverage PlansCoverage PlansCost-sharingCost-sharing Full coverageFull coverage

South South 36%36% 16%16%

WestWest 21%21% 41%41%

Staff/Group Staff/Group ModelModel

7%7% 18%18%

For-profitFor-profit 72%72% 56%56%

Adjusted Negative Effect of Cost-sharing by Adjusted Negative Effect of Cost-sharing by Race and Medicaid EligibilityRace and Medicaid Eligibility

-13.4%

-6.8%-7.8%

-3.7%

-14.0%

-12.0%

-10.0%

-8.0%

-6.0%

-4.0%

-2.0%

0.0%

Medicaid Race

P<0.001 for trends

Yes No White

Black

effect of cost-sharing on screening mammography in medicare managed care plans amal trivedi, md, mph...

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