title: Managed care and the diffusion of intensity-modulated radiotherapy for prostate cancer.
abstract: OBJECTIVE
  To better understand associations between managed care penetration in health care markets and the adoption of intensity-modulated radiotherapy (IMRT).
  
  
  METHODS
  We used Surveillance, Epidemiology, and End Results-Medicare data to identify men diagnosed with prostate cancer between 2001 and 2007 who were treated with radiotherapy (n = 55,162). We categorized managed care penetration in Health Service Areas (HSAs) as low (<3%), intermediate (3%-10%), and high (>10%), and assessed our main outcomes (ie, probability of IMRT adoption, which is the ability of a health care market to deliver IMRT, and IMRT utilization in HSA markets) using a Cox proportional hazards model and Poisson regression model, respectively.
  
  
  RESULTS
  Compared with markets with low managed care penetration, populations in highly penetrated HSAs were more racially diverse (25% vs 15% non-white, P <.01), densely populated (2110 vs 145 people/square mile, P <.01), and wealthier (median income, $48,500 vs $31,900, P <.01). The probability of IMRT adoption was greatest in markets with the highest managed care penetration (eg, 0.82 [high] vs 0.72 [low] in 2007, P = .05). Among adopting markets, the use of IMRT increased in all HSA categories. However, relative to markets with low managed care penetration, IMRT use was constrained in markets with the highest penetration (0.69 [high] vs 0.76 [low] in 2007, P <.01).
  
  
  CONCLUSIONS
  Markets with higher managed care penetration demonstrated a greater propensity for acquiring IMRT technology. However, after adopting IMRT, more highly penetrated markets had roughly 7% slower growth in IMRT use during the study period. These findings provide insight into the implications of delivery system reforms for cancer-related technologies.
authors.affiliation: Department of Urology, Division of Oncology, University of Michigan, Ann Arbor, Michigan 48109-2800, USA. brucejac@med.umich.edu
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Jacobs
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ted A
authors.initials: TA
authors.lastname: Skolarus
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
authors.forename: James E
authors.initials: JE
authors.lastname: Montie
authors.forename: Florian R
authors.initials: FR
authors.lastname: Schroeck
authors.forename: Brent K
authors.initials: BK
authors.lastname: Hollenbeck
mesh_terms: D000368:Aged; D004059:Diffusion of Innovation; D006801:Humans; D008297:Male; D008329:Managed Care Programs; D006278:Medicare; D016016:Proportional Hazards Models; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated; D018426:SEER Program; D014481:United States