title: Evidence of bias affecting the interpretation of the results of local anaesthetic nerve blocks when assessing lameness in horses.
abstract: Eighteen observers were influenced to different extents in the grades of lameness they allocated to eight horses by whether they knew that a nerve block had been administered; on a scale from 0 to 10 the mean difference in grade allocated once the observer knew a horse had been nerve-blocked was increased by 0.4. The consistency of the assessments made by the individual observers was good, with a an average of 0.6 of a grade difference when grading the same horse on two occasions. The agreement between the assessments of four orthopaedic experts was reasonable (+/-1 grade), but significantly poorer for four non-experts and 10 final year veterinary students.
authors.affiliation: Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield.
authors.forename: M
authors.initials: M
authors.lastname: Arkell
authors.forename: R M
authors.initials: RM
authors.lastname: Archer
authors.forename: F J
authors.initials: FJ
authors.lastname: Guitian
authors.forename: S A
authors.initials: SA
authors.lastname: May
mesh_terms: D000818:Animals; D006734:Horse Diseases / Q000175:diagnosis* / Q000473:pathology; D006736:Horses; D007794:Lameness, Animal / Q000175:diagnosis* / Q000473:pathology; D009407:Nerve Block / Q000379:methods / Q000662:veterinary*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013334:Students; D014743:Videotape Recording