title: Influence of experience on intra- and inter-observer reproducibility of the Crowe, Hartofilakidis and modified Cochin classifications.
abstract: BACKGROUND
  A previous study demonstrated that the reproducibility of the Crowe (Cr), the Hartofilakidis (Ha) and the modified Cochin (Co) classifications were comparable. However, there were differences with a trend that suggested the influence of experience. Therefore, we performed a prospective study to investigate whether experience influenced the reproducibility of the commonly used developmental dysplasia of the hip (DDH) classifications.
  
  
  OBJECTIVE
  The hypothesis was that the intra- and inter-observer reproducibility scores would be higher in the senior group than the junior group, and particularly for the modified Co classification.
  
  
  METHODS
  Four seniors and four residents classified 104 A/P pelvic radiographs (200 hips) two times using the Cr, Ha and Co classification systems.
  
  
  RESULTS
  For intra-observer reproducibility, the average weighted concordance coefficients [95% confidence intervals] were for the senior and the junior groups: 92.2 [88.6-95.7] and 92.6 [87.9-97.2] for Cr, 92.1 [88.7-94.6] and 92.0 [87.7-96.3] for Ha, 94.2 [91.8-96.6] and 94.1 [91.5-96.6] for Co. The average weighted Kappa (95% confidence intervals) were 0.8 [0.71-0.88] and 0.79 [0.68-0.89] for Cr, 0.77 [0.74-0.81] and 0.75 [0.62-0.88] for Ha, 0.82 [0.76-0.89] and 0.80 [0.74-0.87] for Co. The junior inter-observer reproducibility multi-rater Kappa (list A:list B) were 0.57:0.50 (Cr), 0.47:0.53 (Ha), 0.42:0.42 (Co). Senior multi-rater Kappa were 0.53:0.49 (Cr), 0.40:0.34 (Ha), 0.40:0.43 (Co).
  
  
  CONCLUSIONS
  Contrary to our hypothesis, the experience of the observer did not affect the intra- and inter-observer reproducibility of the three classification systems.
authors.affiliation: Université de Bretagne Occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; Service de chirurgie orthopédique et traumatologique de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France; LaTIM, Inserm UMR 1101, 2, avenue Foch, 29609 Brest cedex, France. Electronic address: arnaud.clave@orange.fr.
authors.forename: A
authors.initials: A
authors.lastname: Clavé
authors.affiliation: Université de Bretagne Occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; Service de chirurgie orthopédique et traumatologique de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Tristan
authors.affiliation: Université de Bretagne Occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; Service de chirurgie orthopédique et traumatologique de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Desseaux
authors.affiliation: Centre hospitalier de Cornouaille, 14, avenue Thépot, BP 1757, 29107 Quimper cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Gaucher
authors.affiliation: Université de Bretagne Occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; Service de chirurgie orthopédique et traumatologique de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France; LaTIM, Inserm UMR 1101, 2, avenue Foch, 29609 Brest cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Lefèvre
authors.affiliation: Université de Bretagne Occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; Service de chirurgie orthopédique et traumatologique de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France; LaTIM, Inserm UMR 1101, 2, avenue Foch, 29609 Brest cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Stindel
mesh_terms: D000328:Adult; D002983:Clinical Competence; D005260:Female; D006618:Hip Dislocation, Congenital / Q000145:classification* / Q000000981:diagnostic imaging*; D006801:Humans; D007396:Internship and Residency; D008297:Male; D015588:Observer Variation; D010820:Physicians; D011446:Prospective Studies; D015203:Reproducibility of Results
keywords: Classification; Congenital hip disease; Developmental dysplasia hip; Dysplasia; Hip