title: Risk factors for serious underlying pathology in adult emergency department nontraumatic low back pain patients.
abstract: BACKGROUND
  Nontraumatic low back pain (LBP) is a common emergency department (ED) complaint and can be caused by serious pathologies that require immediate intervention or that lead to death.
  
  
  OBJECTIVE
  The primary goal of this study is to identify risk factors associated with serious pathology in adult nontraumatic ED LBP patients.
  
  
  METHODS
  We conducted a health records review and included patients aged ≥ 16 years with nontraumatic LBP presenting to an academic ED from November 2009 to January 2010. We excluded those with previously confirmed nephrolithiasis and typical renal colic presentation. We collected 56 predictor variables and outcomes within 30 days. Outcomes were determined by tracking computerized patient records and performance of univariate analysis and recursive partitioning.
  
  
  RESULTS
  There were 329 patients included, with a mean age of 49.3 years; 50.8% were women. A total of 22 (6.7%) patients suffered outcomes, including one death, five compression fractures, four malignancies, four disc prolapses requiring surgery, two retroperitoneal bleeds, two osteomyelitis, and one each of epidural abscess, cauda equina, and leaking abdominal aortic aneurysm graft. Risk factors identified for outcomes were: anticoagulant use (odds ratio [OR] 15.6; 95% confidence interval [CI] 4.2-58.5), decreased sensation on physical examination (OR 6.9; CI 2.2-21.2), pain that is worse at night (OR 4.3; CI 0.9-20.1), and pain that persists despite appropriate treatment (OR 2.2; CI 0.8-5.6). These four predictors identified serious pathology with 91% sensitivity (95% CI 70-98%) and 55% specificity (95% CI 54-56%).
  
  
  CONCLUSIONS
  We successfully identified risk factors associated with serious pathology among ED LBP patients. Future prospective studies are required to derive a robust clinical decision rule.
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Thiruganasambandamoorthy
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Turko
authors.affiliation: Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Ansell
authors.affiliation: Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Aparna
authors.initials: A
authors.lastname: Vaidyanathan
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: George A
authors.initials: GA
authors.lastname: Wells
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Stiell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057868:Anastomotic Leak / Q000175:diagnosis; D000925:Anticoagulants / Q000009:adverse effects*; D001014:Aortic Aneurysm / Q000601:surgery; D004636:Emergency Service, Hospital; D005260:Female; D050815:Fractures, Compression / Q000150:complications / Q000175:diagnosis; D006470:Hemorrhage / Q000139:chemically induced* / Q000150:complications / Q000175:diagnosis; D006801:Humans; D006987:Hypesthesia / Q000209:etiology*; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000175:diagnosis; D017116:Low Back Pain / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000175:diagnosis; D010019:Osteomyelitis / Q000150:complications / Q000175:diagnosis; D010148:Intractable Pain / Q000209:etiology*; D011128:Polyradiculopathy / Q000150:complications / Q000175:diagnosis; D012187:Retroperitoneal Space; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000150:complications / Q000175:diagnosis; D058017:Vascular Grafting / Q000009:adverse effects; D055815:Young Adult
chemical_list: D000925:Anticoagulants
keywords: emergency department; low back pain; nontraumatic; outcomes; risk stratification