title: A comparison of evidence-based estimates and empirical benchmarks of the appropriate rate of use of radiation therapy in ontario.
abstract: OBJECTIVE
  Estimates of the appropriate rate of use of radiation therapy (RT) are required for planning and monitoring access to RT. Our objective was to compare estimates of the appropriate rate of use of RT derived from mathematical models, with the rate observed in a population of patients with optimal access to RT.
  
  
  METHODS
  The rate of use of RT within 1 year of diagnosis (RT1Y) was measured in the 134,541 cases diagnosed in Ontario between November 2009 and October 2011. The lifetime rate of use of RT (RTLIFETIME) was estimated by the multicohort utilization table method. Poisson regression was used to evaluate potential barriers to access to RT and to identify a benchmark subpopulation with unimpeded access to RT. Rates of use of RT were measured in the benchmark subpopulation and compared with published evidence-based estimates of the appropriate rates.
  
  
  RESULTS
  The benchmark rate for RT1Y, observed under conditions of optimal access, was 33.6% (95% confidence interval [CI], 33.0%-34.1%), and the benchmark for RTLIFETIME was 41.5% (95% CI, 41.2%-42.0%). Benchmarks for RTLIFETIME for 4 of 5 selected sites and for all cancers combined were significantly lower than the corresponding evidence-based estimates. Australian and Canadian evidence-based estimates of RTLIFETIME for 5 selected sites differed widely. RTLIFETIME in the overall population of Ontario was just 7.9% short of the benchmark but 20.9% short of the Australian evidence-based estimate of the appropriate rate.
  
  
  CONCLUSIONS
  Evidence-based estimates of the appropriate lifetime rate of use of RT may overestimate the need for RT in Ontario.
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada. Electronic address: william.mackillop@krcc.on.ca.
authors.forename: William J
authors.initials: WJ
authors.lastname: Mackillop
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada.
authors.forename: Weidong
authors.initials: W
authors.lastname: Kong
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Brundage
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Hanna
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada.
authors.forename: Jina
authors.initials: J
authors.lastname: Zhang-Salomons
authors.affiliation: Division of Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: McLaughlin
authors.affiliation: Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Tyldesley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019985:Benchmarking; D055317:Evidence-Based Practice / Q000706:statistics & numerical data*; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D008297:Male; D008875:Middle Aged; D020380:Needs Assessment / Q000706:statistics & numerical data*; D009369:Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009864:Ontario; D011878:Radiotherapy / Q000706:statistics & numerical data; D055815:Young Adult