title: Medicare modernization and diffusion of endoscopy in FFS medicare.
abstract: OBJECTIVE
  To examine how FFS Medicare utilization of endoscopy procedures for colorectal cancer (CRC) screening changed after implementation of the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) in 2006, which provided subsidized drug coverage and expanded the geographic availability of Medicare managed care plans across the US.
  
  
  METHODS
  Using secondary data from 100% FFS Medicare enrollees, we analyzed endoscopy utilization during two intervals, 2001-2005 and 2006-2009.
  
  
  METHODS
  We examined change in predictors of county-level endoscopy utilization rates based on a conceptual model of market supply and demand with spillovers from managed care practices. The equations for each period were estimated jointly in a spatial lag regression model that properly accounts for both place and time effects, allowing robust assessment of changes over time.
  
  
  METHODS
  All Medicare FFS enrollees with both Parts A and B coverage who were age 65+, remained alive and living in the same state over the interval were included in the analyses. The later interval used a new cohort defined the same as the earlier interval. 100% Medicare denominator files were also used, providing county of address to use for county-level aggregation. The outcome variable was defined as county-level proportion of enrollees who ever used endoscopy over the interval.
  
  
  RESULTS
  Endoscopy utilization by FFS Medicare increased, and became more accessible across the US. Medicare managed care plan spillovers onto FFS Medicare endoscopy utilization changed over time from a significant negative (restraining) effect in the early period to no significant effect by the later period.
  
  
  CONCLUSIONS
  The MMA eased budget constraints for seniors, making endoscopic CRC screening more affordable. The MMA policies also strengthened managed care business prospects, and enrollments in Medicare managed care escalated. The change in managed care spillover effects reflects the gradual acceptance of endoscopic CRC screening procedures, as they emerged as the gold standard during the period.
authors.affiliation: Georgia State University, 1 Park Place, Suite 700, Atlanta, GA, 30304, USA. lmobley@gsu.edu.
authors.forename: Lee R
authors.initials: LR
authors.lastname: Mobley
authors.affiliation: Cedeplar - Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Amaral
authors.affiliation: University of North Carolina, Chapel Hill, USA.
authors.forename: Tzy-Mey
authors.initials: TM
authors.lastname: Kuo
authors.affiliation: Georgia State University, 1 Park Place, Suite 700, Atlanta, GA, 30304, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Georgia State University, 1 Park Place, Suite 700, Atlanta, GA, 30304, USA.
authors.forename: Srimoyee
authors.initials: S
authors.lastname: Bose