title: The Impact of Hospital Size on CMS Hospital Profiling.
abstract: BACKGROUND
  The Centers for Medicare & Medicaid Services (CMS) profile hospitals using a set of 30-day risk-standardized mortality and readmission rates as a basis for public reporting. These measures are affected by hospital patient volume, raising concerns about uniformity of standards applied to providers with different volumes.
  
  
  OBJECTIVE
  To quantitatively determine whether CMS uniformly profile hospitals that have equal performance levels but different volumes.
  
  
  METHODS
  Retrospective analysis of patient-level and hospital-level data using hierarchical logistic regression models with hospital random effects. Simulation of samples including a subset of hospitals with different volumes but equal poor performance (hospital effects=+3 SD in random-effect logistic model).
  
  
  METHODS
  A total of 1,085,568 Medicare fee-for-service patients undergoing 1,494,993 heart failure admissions in 4930 hospitals between July 1, 2005 and June 30, 2008.
  
  
  METHODS
  CMS methodology was used to determine the rank and proportion (by volume) of hospitals reported to perform "Worse than US National Rate."
  
  
  RESULTS
  Percent of hospitals performing "Worse than US National Rate" was ∼40 times higher in the largest (fifth quintile by volume) compared with the smallest hospitals (first quintile). A similar gradient was seen in a cohort of 100 hospitals with simulated equal poor performance (0%, 0%, 5%, 20%, and 85% in quintiles 1 to 5) effectively leaving 78% of poor performers undetected.
  
  
  CONCLUSIONS
  Our results illustrate the disparity of impact that the current CMS method of hospital profiling has on hospitals with higher volumes, translating into lower thresholds for detection and reporting of poor performance.
authors.affiliation: *Mount Sinai Medical Center †Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Sosunov
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Egorova
authors.forename: Hung-Mo
authors.initials: HM
authors.lastname: Lin
authors.forename: Ken
authors.initials: K
authors.lastname: McCardle
authors.forename: Vansh
authors.initials: V
authors.lastname: Sharma
authors.forename: Annetine C
authors.initials: AC
authors.lastname: Gelijns
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Moskowitz
mesh_terms: D014487:Centers for Medicare and Medicaid Services, U.S. / Q000592:standards*; D018588:Fee-for-Service Plans / Q000706:statistics & numerical data; D006276:Health Facility Size / Q000706:statistics & numerical data*; D006333:Heart Failure; D017052:Hospital Mortality; D006761:Hospitals / Q000145:classification / Q000592:standards*; D006801:Humans; D016015:Logistic Models; D010359:Patient Readmission / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care / Q000592:standards*; D012189:Retrospective Studies; D020379:Risk Adjustment / Q000592:standards*; D014481:United States