title: Intra- and inter-observer agreement on diagnosis of Dupuytren disease, measurements of severity of contracture, and disease extent.
abstract: BACKGROUND
  Dupuytren disease (DD) is a fibrosing disease affecting the palmar aponeurosis, and is mostly treated by surgery based on measurement of severity of flexion contracture of the fingers. Literature concerning the measurement reliability is scarce. This study aimed to determine the intra- and inter-observer agreement of four variables for diagnosing DD, determining severity of contracture, and disease extent. One of them is a new measurement on the area of nodules and cords for measuring the disease extent in early disease stages.
  
  
  METHODS
  An agreement study (n = 54) was performed by two trained investigators. Agreement was calculated per finger, based on an intraclass correlation coefficient (ICC) using a latent variable model on subjects for diagnosis and Tubiana stage. For total passive extension deficit (TPED) and the area of nodules and cords, agreement was calculated with an ICC using a one-way random effects model with subject as random effect.
  
  
  RESULTS
  Inter-observer agreement was very good for diagnosing DD (ICC: 95.5%-99.9%) and good to very good for classifying Tubiana stage (ICC: 73.5%-94.9%). Agreements for area and TPED were moderate (middle finger) to very good (ICC: 48.4%-98.6% and 45.0%-99.5%, respectively). Intra-observer agreement was slightly higher on average than inter-observer agreement.
  
  
  CONCLUSIONS
  Overall, the intra- and inter-observer agreement in diagnosing DD, and determining the severity of flexion contracture is high. Also, the newly introduced variable area of nodules and cords has high intra- and inter-observer agreement, indicating that it is suitable to measure disease extent.
authors: University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, HPC BB81, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. Electronic address: d.c.broekstra@umcg.nl.
authors: Dieuwke C
authors: DC
authors: Broekstra
authors: University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, HPC BB81, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. Electronic address: r.lanting@umcg.nl.
authors: Rosanne
authors: R
authors: Lanting
authors: University of Groningen, University Medical Center Groningen, Department of Plastic Surgery, HPC BB81, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. Electronic address: p.m.n.werker@umcg.nl.
authors: Paul M N
authors: PM
authors: Werker
authors: University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, The Netherlands. Electronic address: e.r.v.d.heuvel@tue.nl.
authors: Edwin R
authors: ER
authors: van den Heuvel
mesh_terms: D053587:Arthrometry, Articular / Q000379:methods*; D004387:Dupuytren Contracture / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index
keywords: Articular; Dupuytren contracture; Observer variation; Range of motion; Reproducibility of results