title: What is gross hematuria? Correlation of subjective and objective assessment.
abstract: BACKGROUND
  Gross hematuria is a screening test used to help determine the need for radiographic evaluation in patients with blunt trauma. This subjective assessment has not been compared with objective measures, nor has interrater reliability been described.
  
  
  METHODS
  We performed a prospective, randomized, controlled study to determine the ability of clinicians to assess gross hematuria. Clinicians were asked to assess samples containing various concentrations of blood diluted in urine for the presence of gross hematuria.
  
  
  RESULTS
  Gross hematuria was recognized by more than 95% of clinicians only when samples contained more than 3,500 red blood cells per high-power field. Clinicians' interpretations were independent of profession, specialty, and level of training (p > 0.08).
  
  
  CONCLUSIONS
  Clinicians demonstrate poor sensitivity and interrater reliability identifying gross hematuria by inspection. Clinical studies correlating degrees of hematuria to the need for genitourinary diagnostic evaluation should report both subjective and objective measures to identify a threshold value predictive of renal injury.
authors: Albert Einstein Medical Center, Brooklyn, New York, USA. peacock@nyc.rr.com
authors: P R
authors: PR
authors: Peacock
authors: H L
authors: HL
authors: Souto
authors: G E
authors: GE
authors: Penner
authors: W C
authors: WC
authors: Dalsey
authors: J W
authors: JW
authors: Becher
authors: J L
authors: JL
authors: Kaplan
mesh_terms: D002983:Clinical Competence; D016001:Confidence Intervals; D006417:Hematuria / Q000175:diagnosis*; D006801:Humans; D015588:Observer Variation; D011446:Prospective Studies; D012680:Sensitivity and Specificity