title: Preoperative testing before low-risk surgical procedures.
abstract: BACKGROUND
  There is concern about increasing utilization of low-value health care services, including preoperative testing for low-risk surgical procedures. We investigated temporal trends, explanatory factors, and institutional and regional variation in the utilization of testing before low-risk procedures.
  
  
  METHODS
  For this retrospective cohort study, we accessed linked population-based administrative databases from Ontario, Canada. A cohort of 1 546 223 patients 18 years or older underwent a total of 2 224 070 low-risk procedures, including endoscopy and ophthalmologic surgery, from Apr. 1, 2008, to Mar. 31, 2013, at 137 institutions in 14 health regions. We used hierarchical logistic regression models to assess patient- and institution-level factors associated with electrocardiography (ECG), transthoracic echocardiography, cardiac stress test or chest radiography within 60 days before the procedure.
  
  
  RESULTS
  Endoscopy, ophthalmologic surgery and other low-risk procedures accounted for 40.1%, 34.2% and 25.7% of procedures, respectively. ECG and chest radiography were conducted before 31.0% (95% confidence interval [CI] 30.9%-31.1%) and 10.8% (95% CI 10.8%-10.8%) of procedures, respectively, whereas the rates of preoperative echocardiography and stress testing were 2.9% (95% CI 2.9%-2.9%) and 2.1% (95% CI 2.1%-2.1%), respectively. Significant variation was present across institutions, with the frequency of preoperative ECG ranging from 3.4% to 88.8%. Receipt of preoperative ECG and radiography were associated with older age (among patients 66-75 years of age, for ECG, adjusted odds ratio [OR] 18.3, 95% CI 17.6-19.0; for radiography, adjusted OR 2.9, 95% CI 2.8-3.0), preoperative anesthesia consultation (for ECG, adjusted OR 8.7, 95% CI 8.5-8.8; for radiography, adjusted OR 2.2, 95% CI 2.1-2.2) and preoperative medical consultation (for ECG, adjusted OR 6.8, 95% CI 6.7-6.9; for radiography, adjusted OR 3.6, 95% CI 3.5-3.6). The median ORs for receipt of preoperative ECG and radiography were 2.3 and 1.6, respectively.
  
  
  CONCLUSIONS
  Despite guideline recommendations to limit testing before low-risk surgical procedures, preoperative ECG and chest radiography were performed frequently. Significant variation across institutions remained after adjustment for patient- and institution-level factors.
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Kirkham
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Duminda N
authors.initials: DN
authors.lastname: Wijeysundera
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Ciara
authors.initials: C
authors.lastname: Pendrith
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Ryan
authors.initials: R
authors.lastname: Ng
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Jack V
authors.initials: JV
authors.lastname: Tu
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Andreas
authors.initials: A
authors.lastname: Laupacis
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schull
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont.
authors.forename: Wendy
authors.initials: W
authors.lastname: Levinson
authors.affiliation: Department of Anesthesia and Pain Management (Kirkham), Toronto Western Hospital, University of Toronto, Toronto, Ont.; Department of Anesthesia (Kirkham) and Institute for Health System Solutions and Virtual Care (Pendrith, Bhatia), Women's College Hospital, Toronto, Ont.; Li Ka Shing Knowledge Institute (Wijeysundera, Laupacis), St. Michael's Hospital, Toronto, Ont.; Department of Anesthesia and Pain Management (Wijeysundera), Toronto General Hospital, University of Toronto, Toronto, Ont.; Department of Medicine (Wijeysundera, Tu, Laupacis, Schull, Levinson), University of Toronto, Toronto, Ont.; Institute for Clinical Evaluative Sciences (Ng, Tu, Laupacis, Schull, Bhatia), Toronto, Ont.; Division of Cardiology (Tu), Sunnybrook Schulich Heart Centre, Toronto, Ont.; Sunnybrook Research Institute (Schull), Toronto, Ont.; Division of Cardiology (Bhatia), University Health Network, Toronto, Ont. sacha.bhatia@wchospital.ca.
authors.forename: R Sacha
authors.initials: RS
authors.lastname: Bhatia
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016208:Databases, Factual; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D004724:Endoscopy / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods / Q000706:statistics & numerical data; D009864:Ontario; D013508:Ophthalmologic Surgical Procedures / Q000379:methods / Q000706:statistics & numerical data*; D017063:Outcome Assessment, Health Care; D011300:Preoperative Care / Q000379:methods* / Q000706:statistics & numerical data; D011786:Quality Control; D013902:Radiography, Thoracic / Q000379:methods / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D018570:Risk Assessment; D017751:Safety Management