title: Geographic variation in cardiovascular procedure use among Medicare fee-for-service vs Medicare Advantage beneficiaries.
abstract: OBJECTIVE
  Little is known about how different financial incentives between Medicare Advantage and Medicare fee-for-service (FFS) reimbursement structures influence use of cardiovascular procedures.
  
  
  OBJECTIVE
  To compare regional cardiovascular procedure rates between Medicare Advantage and Medicare FFS beneficiaries.
  
  
  METHODS
  Cross-sectional study of Medicare beneficiaries older than 65 years between 2003-2007 comparing rates of coronary angiography, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) surgery across 32 hospital referral regions in 12 states.
  
  
  METHODS
  Rates of coronary angiography, PCI, and CABG surgery.
  
  
  RESULTS
  We evaluated a total of 878,339 Medicare Advantage patients and 5,013,650 Medicare FFS patients. Compared with Medicare FFS patients, Medicare Advantage patients had lower age-, sex-, race-, and income-adjusted procedure rates per 1000 person-years for angiography (16.5 [95% CI, 14.8-18.2] vs 25.9 [95% CI, 24.0-27.9]; P < .001) and PCI (6.8 [95% CI, 6.0-7.6] vs 9.8 [95% CI, 9.0-10.6]; P < .001) but similar rates for CABG surgery (3.1 [95% CI, 2.8-3.5] vs 3.4 [95% CI, 3.1-3.7]; P = .33). There were no significant differences between Medicare Advantage and Medicare FFS patients in the rates per 1000 person-years of urgent angiography (3.9 [95% CI, 3.6-4.2] vs 4.3 [95% CI, 4.0-4.6]; P = .24) or PCI (2.4 [95% CI, 2.2-2.7] vs 2.7 [95% CI, 2.5-2.9]; P = .16). Procedure rates varied widely across hospital referral regions among Medicare Advantage and Medicare FFS patients. For angiography, the rates per 1000 person-years ranged from 9.8 to 40.6 for Medicare Advantage beneficiaries and from 15.7 to 44.3 for Medicare FFS beneficiaries. For PCI, the rates ranged from 3.5 to 16.8 for Medicare Advantage and from 4.7 to 16.1 for Medicare FFS. The rates for CABG surgery ranged from 1.5 to 6.1 for Medicare Advantage and from 2.5 to 6.0 for Medicare FFS. Across regions, we found no statistically significant correlation between Medicare Advantage and Medicare FFS beneficiary utilization for angiography (Spearman r = 0.19, P = .29) and modest correlations for PCI (Spearman r = 0.33, P = .06) and CABG surgery (Spearman r = 0.35, P = .05). Among Medicare Advantage beneficiaries, adjustment for additional cardiac risk factors had little influence on procedure rates.
  
  
  CONCLUSIONS
  Although Medicare beneficiaries enrolled in capitated Medicare Advantage programs had lower angiography and PCI procedure rates than those enrolled in Medicare FFS, the degree of geographic variation in procedure rates was substantial among Medicare Advantage beneficiaries and was similar in magnitude to that observed among Medicare FFS beneficiaries.
authors.affiliation: Division of General Internal Medicine, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA. daniel.matlock@ucdenver.edu
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Matlock
authors.forename: Peter W
authors.initials: PW
authors.lastname: Groeneveld
authors.forename: Steve
authors.initials: S
authors.lastname: Sidney
authors.forename: Susan
authors.initials: S
authors.lastname: Shetterly
authors.forename: Glenn
authors.initials: G
authors.lastname: Goodrich
authors.forename: Karen
authors.initials: K
authors.lastname: Glenn
authors.forename: Stan
authors.initials: S
authors.lastname: Xu
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Steven A
authors.initials: SA
authors.lastname: Farmer
authors.forename: Kristi
authors.initials: K
authors.lastname: Reynolds
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Cassidy-Bushrow
authors.forename: Tracy
authors.initials: T
authors.lastname: Lieu
authors.forename: Denise M
authors.initials: DM
authors.lastname: Boudreau
authors.forename: Robert T
authors.initials: RT
authors.lastname: Greenlee
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Tom
authors.forename: Suma
authors.initials: S
authors.lastname: Vupputuri
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Adams
authors.forename: David H
authors.initials: DH
authors.lastname: Smith
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Gunter
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
authors.forename: David J
authors.initials: DJ
authors.lastname: Magid
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002204:Capitation Fee; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D018588:Fee-for-Service Plans / Q000706:statistics & numerical data*; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D020398:Medicare Part C / Q000706:statistics & numerical data*; D062645:Percutaneous Coronary Intervention / Q000706:statistics & numerical data*; D012052:Reimbursement, Incentive; D012737:Sex Factors; D014481:United States