title: Inter-observer reliability of ten tests used for predicting difficult tracheal intubation.
abstract: OBJECTIVE
  To determine inter-observer reliability of ten preoperative airway assessment tests used for predicting difficult tracheal intubation.
  
  
  METHODS
  We prospectively assessed 59 patients undergoing elective surgery requiring tracheal intubation at a large metropolitan teaching hospital. Two experienced observers independently conducted the airway assessment tests on the same group of patients. Inter-observer reliability was examined using Kappa (K) and intraclass correlation coefficient (ICC).
  
  
  RESULTS
  Two tests--mouth opening (ICC = 0.93) and chin protrusion (ICC = 0.89)--had excellent inter-observer reliability. Seven tests--thyromental distance (ICC - 0.74), subluxation (K = 0.66), atlanto-occipital extension distance (ICC = 0.67) and angle (K = 0.66), profile classification (K = 0.58), ramus length (ICC = 0.53), oropharyngeal best view (K = 0.49)--were moderately reliable. One test--Mallampati technique of assessing oropharyngeal view (K = 0.31)--had poor reliability.
  
  
  CONCLUSIONS
  Many of the preoperative airway tests have only moderate inter-observer reliability. This may provide some insight into why previous research has failed to show that the tests accurately predict difficult tracheal intubation.
authors.affiliation: Department of Anaesthesia, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Karkouti
authors.forename: D K
authors.initials: DK
authors.lastname: Rose
authors.forename: L E
authors.initials: LE
authors.lastname: Ferris
authors.forename: D F
authors.initials: DF
authors.lastname: Wigglesworth
authors.forename: T
authors.initials: T
authors.lastname: Meisami-Fard
authors.forename: H
authors.initials: H
authors.lastname: Lee
mesh_terms: D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology; D015982:Bias; D002680:Chin / Q000033:anatomy & histology; D017558:Elective Surgical Procedures; D005145:Face; D005544:Forecasting; D006801:Humans; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data; D008334:Mandible / Q000033:anatomy & histology / Q000502:physiology; D009055:Mouth / Q000033:anatomy & histology; D009068:Movement; D009333:Neck / Q000033:anatomy & histology; D015588:Observer Variation; D009960:Oropharynx / Q000033:anatomy & histology; D011446:Prospective Studies; D015203:Reproducibility of Results; D013961:Thyroid Gland