title: Impact of system and physician factors on the detection of obstructive coronary disease with diagnostic angiography in stable ischemic heart disease.
abstract: BACKGROUND
  Wide variation exists in the detection rate of obstructive coronary artery disease (CAD) with elective coronary angiography for suspected stable ischemic heart disease. We sought to understand the incremental impact of nonclinical factors on this variation.
  
  
  RESULTS
  We included all patients who underwent coronary angiography for possible suspected stable ischemic heart disease, from October 1, 2008, to September 30, 2011, in Ontario, Canada. Nonclinical factors of interest included physician self-referral for angiography, the physician type (invasive or interventional), and hospital type. Hospitals were categorized into diagnostic angiogram only centers, stand-alone percutaneous coronary intervention centers, or full service centers with coronary artery bypass surgery available. Multivariable hierarchical logistic models were developed to identify system and physician-level predictors of obstructive CAD, after adjustment for patient factors. Our cohort consisted of 60 986 patients, of whom 31 726 had obstructive CAD (52.0%), with significant range across hospitals from 37.3% to 69.2%. Fewer self-referral patients (49.8%) had obstructive CAD compared with nonself-referral patients (53.5%), with an odds ratio of 0.89 (95% confidence interval, 0.86-0.93; P<0.001). Angiograms performed by invasive physicians had a lower likelihood of obstructive CAD compared with those by interventional physicians (48.2% versus 56.9%; odds ratio, 0.85; 95% confidence interval, 0.81-0.90; P<0.001). Fewer angiograms at diagnostic only centers showed obstructive CAD (42.0%) compared with full service centers (55.1%; odds ratio, 0.62; 95% confidence interval, 0.39-0.98; P=0.04). Nonclinical factors accounted for 23.8% of the variation between hospitals.
  
  
  CONCLUSIONS
  Physician and system factors are important predictors of obstructive CAD with coronary angiography.
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.). harindra.wijeysundera@sunnybrook.ca.
authors.forename: Harindra C
authors.initials: HC
authors.lastname: Wijeysundera
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Maria C
authors.initials: MC
authors.lastname: Bennell
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Madhu K
authors.initials: MK
authors.lastname: Natarajan
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Cantor
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Stuart
authors.initials: S
authors.lastname: Smith
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Kori J
authors.initials: KJ
authors.lastname: Kingsbury
authors.affiliation: From the Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences Centre (H.C.W, M.C.B., D.T.K.) and Institute of Health Policy, Management, and Evaluation (H.C.W., D.T.K.), University of Toronto, Toronto, Ontario, Canada; Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (H.C.W., F.Q., D.T.K.); Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario, Canada (H.C.W.); Hamilton Health Sciences Centre, Hamilton, Ontario, Canada (M.K.N.); Southlake Regional Health Centre, Newmarket, Ontario, Canada (W.J.C.); St Mary's Hospital, Kitchener, Ontario, Canada (S.S.); and Cardiac Care Network of Ontario, North York, Ontario, Canada (K.J.K.).
authors.forename: Dennis T
authors.initials: DT
authors.lastname: Ko
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D002170:Canada; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology*; D003695:Delivery of Health Care; D018450:Disease Progression; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D062645:Percutaneous Coronary Intervention; D018584:Physician Self-Referral; D010820:Physicians / Q000706:statistics & numerical data; D011859:Radiography; D016896:Treatment Outcome
keywords: angiography; coronary disease