title: Poor sensitivity of a modified Alvarado score in adults with suspected appendicitis.
abstract: OBJECTIVE
  A clinical decision rule that identifies patients at low risk for appendicitis may reduce the reliance on computed tomography (CT) for diagnosis. We seek to prospectively evaluate the accuracy of a low modified Alvarado score in emergency department (ED) patients with suspected appendicitis and compare the score to clinical judgment. We hypothesize that a low modified Alvarado score will have a sufficiently high sensitivity to rule out acute appendicitis.
  
  
  METHODS
  We performed a prospective observational study of adult patients with suspected appendicitis at 2 academic urban EDs. A low modified Alvarado score was defined as less than 4. The sensitivity and specificity were calculated with 95% confidence interval (CI) for a low modified Alvarado score, and a final diagnosis of appendicitis was confirmed by CT, laparotomy, or 7-day follow-up.
  
  
  RESULTS
  Two hundred sixty-one patients were included for analysis (mean age 35 years [range 18 to 89 years], 68% female patients, 52% white). Fifty-three patients (20%) had acute appendicitis. The modified Alvarado score test characteristics demonstrated a sensitivity and specificity of 72% (95% CI 58% to 84%) and 54% (95% CI 47% to 61%), respectively. Unstructured clinical judgment that appendicitis was either the most likely or second most likely diagnosis demonstrated a sensitivity and specificity of 93% (95% CI 82% to 98%) and 33% (95% CI 27% to 40%), respectively.
  
  
  CONCLUSIONS
  With a sensitivity of 72%, a low modified Alvarado score is less sensitive than clinical judgment in excluding acute appendicitis.
authors.affiliation: Department of Emergency Medicine, George Washington University, Washington, DC, USA. ameltzer@mfa.gwu.edu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Meltzer
authors.forename: Brigitte M
authors.initials: BM
authors.lastname: Baumann
authors.forename: Esther H
authors.initials: EH
authors.lastname: Chen
authors.forename: Frances S
authors.initials: FS
authors.lastname: Shofer
authors.forename: Angela M
authors.initials: AM
authors.lastname: Mills
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000175:diagnosis*; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult