title: A Clinical Decision Rule to Identify Emergency Department Patients at Low Risk for Acute Coronary Syndrome Who Do Not Need Objective Coronary Artery Disease Testing: The No Objective Testing Rule.
abstract: OBJECTIVE
  We derive a clinical decision rule for ongoing investigation of patients who present to the emergency department (ED) with chest pain. The rule identifies patients who are at low risk of acute coronary syndrome and could be discharged without further cardiac testing.
  
  
  METHODS
  This was a prospective observational study of 2,396 patients who presented to 2 EDs with chest pain suggestive of acute coronary syndrome and had normal troponin and ECG results 2 hours after presentation. Research nurses collected clinical data on presentation, and the primary endpoint was diagnosis of acute coronary syndrome within 30 days of presentation to the ED. Logistic regression analyses were conducted on 50 bootstrapped samples to identify predictors of acute coronary syndrome. A rule was derived and diagnostic accuracy statistics were computed.
  
  
  RESULTS
  Acute coronary syndrome was diagnosed in 126 (5.3%) patients. Regression analyses identified the following predictors of acute coronary syndrome: cardiac risk factors, age, sex, previous myocardial infarction, or coronary artery disease and nitrate use. A rule was derived that identified 753 low-risk patients (31.4%), with sensitivity 97.6% (95% confidence interval [CI] 93.2% to 99.5%), negative predictive value 99.6% (95% CI 98.8% to 99.9%), specificity 33.0% (95% CI 31.1% to 35.0%), and positive predictive value 7.5% (95% CI 6.3% to 8.9%) for acute coronary syndrome. This was referred to as the no objective testing rule.
  
  
  CONCLUSIONS
  We have derived a clinical decision rule for chest pain patients with negative early cardiac biomarker and ECG testing results that identifies 31% at low risk and who may not require objective testing for coronary artery disease. A prospective trial is required to confirm these findings.
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; School of Medicine, The University of Queensland, Brisbane, Queensland, Australia; School of Public Health, Queensland University of Technology, Brisbane, Queensland, Australia. Electronic address: jaimi_greenslade@health.qld.gov.au.
authors.forename: Jaimi H
authors.initials: JH
authors.lastname: Greenslade
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; School of Medicine, The University of Queensland, Brisbane, Queensland, Australia; School of Public Health, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: William
authors.initials: W
authors.lastname: Parsonage
authors.affiliation: School of Medicine, University of Otago, Christchurch, New Zealand; Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; School of Public Health, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Adam
authors.initials: A
authors.lastname: Scott
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Sally
authors.initials: S
authors.lastname: Aldous
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: John W
authors.initials: JW
authors.lastname: Pickering
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hammett
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; School of Medicine, The University of Queensland, Brisbane, Queensland, Australia; School of Public Health, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Cullen
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003661:Decision Support Techniques; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D015415:Biomarkers