title: Rapid expansion of intravitreal drug injection procedures, 2000 to 2008: a population-based analysis.
abstract: OBJECTIVE
  To evaluate patterns of care for age-related macular degeneration following the introduction of vascular endothelial growth factor inhibitors.
  
  
  METHODS
  Using a population-based retrospective design, we studied monthly fee claims for intravitreal injections submitted to the Ontario Health Insurance Plan between January 1, 2000, and March 30, 2008, and linked procedures to the physicians who performed them. This database records physician services provided as part of universal health care insurance coverage in Ontario, Canada. This program covers all residents of Ontario, which had an average population of 12.1 million during the study period.
  
  
  RESULTS
  Following regulatory approval of bevacizumab for colorectal cancer in 2005, off-label use of this drug for the treatment of retinal disease, particularly age-related macular degeneration, became increasingly common. The rate of intravitreal injections in Ontario rapidly grew 8-fold, and this growth preceded the availability of ranibizumab by more than a year. Moreover, in 2007, more than 50% of intravitreal injections in Ontario were performed by 3% of ophthalmologists.
  
  
  CONCLUSIONS
  The development of vascular endothelial growth factor inhibitors has revolutionized the treatment of age-related macular degeneration. To our knowledge, this study is the first to quantify the dramatic uptake of these treatments at a population level. Our findings also suggest that off-label injection of bevacizumab was highly prevalent in Ontario. Serial intravitreal injections requiring direct physician administration and the concentration of injection procedures in the hands of a small number of ophthalmologists have the potential to affect services for other vision-threatening conditions.
authors.affiliation: Department of Ophthalmology, Queen's University and Hotel Dieu Hospital, 166 Brock St, Kingston, ON K7L 5G2, Canada. rob.campbell@queensu.ca
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Campbell
authors.forename: Susan E
authors.initials: SE
authors.lastname: Bronskill
authors.forename: Chaim M
authors.initials: CM
authors.lastname: Bell
authors.forename: J Michael
authors.initials: JM
authors.lastname: Paterson
authors.forename: Marlo
authors.initials: M
authors.lastname: Whitehead
authors.forename: Sudeep S
authors.initials: SS
authors.lastname: Gill
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage* / Q000191:economics; D016503:Drug Delivery Systems / Q000639:trends*; D006302:Health Services Research; D006801:Humans; D007267:Injections; D007345:Insurance Claim Review / Q000191:economics; D008268:Macular Degeneration / Q000188:drug therapy*; D009864:Ontario; D009885:Ophthalmology / Q000191:economics / Q000639:trends*; D010818:Practice Patterns, Physicians' / Q000191:economics / Q000639:trends*; D012189:Retrospective Studies; D019472:Universal Health Insurance / Q000191:economics; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*; D014822:Vitreous Body
chemical_list: D020533:Angiogenesis Inhibitors; D042461:Vascular Endothelial Growth Factor A