title: Geographic Variation of Endoscopic Sinus Surgery in Canada: An Alberta-Based Small Area Variation Analysis.
abstract: OBJECTIVE
  With an estimated 10,000 to 15,000 endoscopic sinus surgery (ESS) cases performed in Canada each year, identifying potential unwarranted practice patterns is important. The objective of this study is to examine the rates and geographic variation of ESS in the province of Alberta, Canada.
  
  
  METHODS
  Small area variation analysis.
  
  
  METHODS
  Province of Alberta, Canada.
  
  
  METHODS
  The National Ambulatory Care Reporting System database was searched to identify all patients who received ESS between April 1, 2010, and March 31, 2013, in Alberta, Canada. The annual adjusted rates of ESS per 1000 people were calculated for each Alberta health zone and health status area. Geographic variations were evaluated with the extremal quotient, weighted coefficient of variation, and systematic component of variance. Chi-squared-test was used to quantify the significance of variation of the adjusted ESS rates across regions.
  
  
  RESULTS
  The annual adjusted rate of ESS was 0.33 per 1000 people in Alberta, Canada. The mean extremal quotient for health status areas was 6.9, indicating a 7-fold difference between the highest and lowest regions. The mean coefficient of variation was 41.0, and the mean systematic component of variance was 10.5, which demonstrates "very high" variation.
  
  
  CONCLUSIONS
  This study observed very high geographic variation in the rates of ESS across the province of Alberta. Given the negative impact of unwarranted surgical variation on quality of care, outcomes from this study indicate a need to further evaluate the delivery of care for ESS in Canada to improve overall health system performance.
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Calgary, Calgary, Alberta, Canada Lukerudmik@gmail.com.
authors.forename: Luke
authors.initials: L
authors.lastname: Rudmik
authors.affiliation: Data Integration, Measurement and Reporting, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Ceris
authors.initials: C
authors.lastname: Bird
authors.affiliation: Data Integration, Measurement and Reporting, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Stafford
authors.initials: S
authors.lastname: Dean
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Dort
authors.affiliation: Data Integration, Measurement and Reporting, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Schorn
authors.affiliation: Data Integration, Measurement and Reporting, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Edward
authors.initials: E
authors.lastname: Kukec
mesh_terms: D000416:Alberta / Q000453:epidemiology; D002908:Chronic Disease; D004724:Endoscopy / Q000706:statistics & numerical data*; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D015994:Incidence; D010256:Paranasal Sinuses / Q000601:surgery*; D011788:Quality of Life; D012189:Retrospective Studies; D012220:Rhinitis / Q000453:epidemiology / Q000601:surgery*; D012852:Sinusitis / Q000453:epidemiology / Q000601:surgery*; D017062:Small-Area Analysis
keywords: Canada; appropriateness; chronic rhinosinusitis; endoscopic sinus surgery; quality of care; sinusitis; variation