Effect of Cost-Sharing on Screening Mammography in Medicare Managed Care Plans Amal Trivedi, MD, MPH William Rakowski, PhD John Ayanian, MD, MPP 2007 AcademyHealth Annual Research Meeting

Background Cost-sharing affects nearly every American with health insurance Cost-sharing affects nearly every American with health insurance Copayments reduce moral hazard to “overconsume” health care with full insurance Copayments reduce moral hazard to “overconsume” health care with full insurance May also reduce use of appropriate preventive care May also reduce use of appropriate preventive care Several well-known studies of cost-sharing have excluded the elderly Several well-known studies of cost-sharing have excluded the elderly

Objectives To determine the prevalence of mammography cost-sharing in Medicare health plans To understand the impact of cost-sharing on the appropriate use of mammography To assess effects of mammography cost-sharing on vulnerable population groups

Sources of Data Medicare HEDIS data Medicare HEDIS data Medicare enrollment file Medicare enrollment file CMS health plan benefit data CMS health plan benefit data 2004 Interstudy Competitive Edge database 2004 Interstudy Competitive Edge database

Study Population Included women age who had been assessed for the HEDIS breast cancer screening indicator Included women age who had been assessed for the HEDIS breast cancer screening indicator Excluded women who died during the measurement year Excluded women who died during the measurement year Final study population: 366,475 women in 174 health plans 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 Independent variable: enrollment in a plan with >$10 or >10% coinsurance for screening mammography Dependent variable: receipt of a biennial screening mammogram Dependent variable: receipt of a biennial screening mammogram Covariates: Covariates: Individual-level: race (black, white, other), zip code level income and education, buy-in eligibility, year Individual-level: race (black, white, other), zip code level income and education, buy-in eligibility, year Plan-level: census region, model type, plan size, plan age, tax- status Plan-level: census region, model type, plan size, plan age, tax- status

Analyses - Main Sample Assessed characteristics of enrollees and breast cancer screening rates in cost-sharing and full- coverage plans Assessed characteristics of enrollees and breast cancer screening rates in cost-sharing and full- coverage plans Constructed multivariate regression models adjusting for individual and plan covariates and clustering by plan Constructed multivariate regression models adjusting for individual and plan covariates and clustering by plan Included interactions of cost-sharing with income, education, race and buy-in eligibility Included interactions of cost-sharing with income, education, race and buy-in eligibility

Analyses - Subsample Identified seven plans that changed from full coverage to cost-sharing Identified seven plans that changed from full coverage to cost-sharing Performed a difference-in-difference analysis by comparing longitudinal changes in screening compared to 14 matched control plans Performed a difference-in-difference analysis by comparing longitudinal changes in screening compared to 14 matched control plans Plans matched based on: Plans matched based on: Census region Census region Profit-status Profit-status Model type Model type

Trends in Mammography Cost-sharing Year # of plans (N=174) % of women in cost-sharing plans Median copayment $20 (Range $13-$35) 5 plans charged 20% coinsurance

Characteristics of Enrollees in Cost-Sharing and Full Coverage Plans Cost-Sharing Full Coverage Age (y) Black (%) 2310 Below Poverty (%) 119 College Attendance (%) 3235 Buy-in (%) 107

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

Adjusted Impact of Cost-sharing on Screening Mammography Effect of Cost- sharing 95% CI/p Unadjusted-8.3% Adjusted for SES, plan characteristics, and clustering by plan -7.2% -9.7%, -4.6% P<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 and Education P<0.001 for trends

Mammography Rates in plans that instituted cost- sharing compared to matched controls Change∆-∆ Adjusted ∆-∆ Added cost- sharing 74.8% Maintained full coverage 71.9%

Mammography Rates in 7 Plans that Instituted Cost- sharing in 2003 Compared to 14 Matched Control Plans Change Added cost- sharing 74.8%69.3%-5.5% Maintained full coverage 71.9%75.3%+3.4%

Mammography Rates in 7 Plans that Instituted Cost- sharing in 2003 Compared to 14 Matched Control Plans Change∆-∆Adj.∆-∆ Added cost- sharing 74.8%69.3%-5.5%-8.9% Maintained full coverage 71.9%75.3%+3.4%

Mammography Rates in 7 Plans that Instituted Cost- sharing in 2003 Compared to 14 Matched Control Plans Change∆-∆Adj.∆-∆ Added cost- sharing 74.8%69.3%-5.5%-8.9%-8.8% (-4.0, -13.6%) P=0.002 Maintained full coverage 71.9%75.3%+3.4%

Limitations Women not randomly assigned to cost-sharing plans Women not randomly assigned to cost-sharing plans Unable to analyze differential impacts of specific copayment amounts Unable to analyze differential impacts of specific copayment amounts Lacked information on rescreening Lacked information on rescreening Zip-code proxies for income and education Zip-code proxies for income and education Limited to Medicare managed care Limited to Medicare managed care

Conclusions Copayments of >$10 or coinsurance of >10% associated with lower rates of breast cancer screening Copayments of >$10 or coinsurance of >10% associated with lower rates of breast cancer screening Cost-sharing disproportionately affects vulnerable populations Cost-sharing disproportionately affects vulnerable populations Prevalence of cost-sharing is dramatically increasing in Medicare managed care Prevalence of cost-sharing is dramatically increasing in Medicare managed care

Implications Cost-sharing should be tailored to the underlying value of the health service Cost-sharing should be tailored to the underlying value of the health service Eliminating copayments may increase adherence to appropriate preventive care Eliminating copayments may increase adherence to appropriate preventive care Important implications for Medicare FFS, where enrollees without supplemental coverage face 20% coinsurance Important implications for Medicare FFS, where enrollees without supplemental coverage face 20% coinsurance

Moral Hazard “If your office gives you and your co-workers all the free Pepsi you want—if your employer, in effect, offers universal Pepsi insurance—you’ll drink more Pepsi than you would have otherwise.” “If your office gives you and your co-workers all the free Pepsi you want—if your employer, in effect, offers universal Pepsi insurance—you’ll drink more Pepsi than you would have otherwise.” - Malcolm Gladwell “The Myth of Moral Hazard”, in The New Yorker, August 29, 2005

Study Population 24,468,528 observations in HEDIS data from Matched to Enrollment File (97% match rate) 23,656,038 observations 2,189,983 observations from 178 plans from Excluded males, enrollees not between 65-69, persons who died in measurement year, and observations from ,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 Enrollees in Cost-Sharing and Full Coverage Plans Cost-sharing Full coverage South36%16% West21%41% Staff/Group Model 7%18% For-profit72%56%

Adjusted Negative Effect of Cost-sharing by Race and Medicaid Eligibility P<0.001 for trends YesNoWhiteBlack