title: Risk Factors Associated with Urologic Intervention in Emergency Department Patients with Suspected Renal Colic.
abstract: BACKGROUND
  Whereas most patients with urolithiasis pass their stones spontaneously and require only symptomatic management, a minority will require urologic intervention.
  
  
  OBJECTIVE
  Our primary objective was to confirm previously reported risk factors and to identify additional predictors of urologic intervention within 90 days, for emergency department (ED) patients with suspected renal colic.
  
  
  METHODS
  We conducted a prospective cohort study of adult patients presenting to one of two tertiary care EDs with suspected renal colic over a 20-month period. Multivariate logistic regression models determined predictor variables independently associated with urologic intervention.
  
  
  RESULTS
  Of the 565 patients included in the analysis, 220 (38.9%) patients had a ureteric stone visualized on diagnostic imaging. Eighty-four patients (14.9%) had urologic intervention within 90 days of their initial ED visit. Urinary nitrites (odds ratio [OR] 4.2, 95% confidence interval [CI] 1.3-13.6), stone size ≥ 5 mm (OR 4.2, 95% CI 2.4-7.4), proximal ureteric stone (OR 3.1, 95% CI 1.5-6.4), age ≥ 50 years (OR 2.8, 95% CI 1.5-5.0), tachycardia at triage (OR 2.5, 95% CI 1.1-5.4), urinary leukocyte esterase (OR 2.3, 95% CI 1.2-4.5), abnormal serum white blood cells (OR 2.0, 95% CI 1.2-3.3), and history of renal colic (OR 1.8, 95% CI 1.1-3.1) were factors independently associated with urologic intervention within 90 days.
  
  
  CONCLUSIONS
  Our study reports eight risk factors associated with urologic intervention within 90 days in patients presenting to the ED with renal colic. These risk factors should be considered when making management, prognostic, and disposition decisions for patients with suspected urolithiasis.
authors.affiliation: Division of Emergency Medicine, Department of Medicine, The University of Western Ontario and Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Justin W
authors.initials: JW
authors.lastname: Yan
authors.affiliation: Division of Emergency Medicine, Department of Medicine, The University of Western Ontario and Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Shelley L
authors.initials: SL
authors.lastname: McLeod
authors.affiliation: Division of Emergency Medicine, Department of Medicine, The University of Western Ontario and Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Edmonds
authors.affiliation: Division of Emergency Medicine, Department of Medicine, The University of Western Ontario and Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sedran
authors.affiliation: Division of Emergency Medicine, Department of Medicine, The University of Western Ontario and Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Karl D
authors.initials: KD
authors.lastname: Theakston
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000652:urine; D003952:Diagnostic Imaging; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000473:pathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009573:Nitrites / Q000652:urine; D011446:Prospective Studies; D056844:Renal Colic / Q000209:etiology* / Q000628:therapy; D012307:Risk Factors; D013610:Tachycardia / Q000453:epidemiology; D052878:Urolithiasis / Q000175:diagnosis* / Q000628:therapy
chemical_list: D009573:Nitrites; C021443:leukocyte esterase; D002265:Carboxylic Ester Hydrolases
keywords: emergency medicine; risk factors; urolithiasis; urologic intervention