title: Inter- and Intra-Rater Reliability of the Visual Vertical in Subacute Stroke.
abstract: OBJECTIVE
  Visual vertical (VV) has been used increasingly as a routine clinical assessment to identify alteration of verticality perception as a possible cause of postural disorders after stroke. This study aims to determine whether the reliability of VV is sufficient to support a wide clinical use in neurorehabilitation for monitoring of patients with stroke.
  
  
  METHODS
  Twenty patients with subacute stroke in neurorehabilitation unit were tested after a first and unique hemispheric stroke. To evaluate the inter-rater reliability, VV was assessed the same day by 2 examiners whose degrees of expertise differed. The second examiner repeated the test the next day to investigate intrarater reliability. VV orientation (mean, primary criterion) and uncertainty (SD, secondary criterion) were calculated for 10 trials. Their reliability was quantified by the intraclass correlation coefficient, Bland-Altman plots, and the minimal detectable change. The concordance between 2 examiners was quantified by Cohen's κ coefficients (κ).
  
  
  RESULTS
  About VV orientation, inter- and intrarater reliability were excellent (intraclass correlation coefficient, 0.979 and 0.982). The Bland-Altman plots and the minimal detectable change revealed a difference inferior to 2° between 2 tests. The concordance between 2 assessments for the diagnosis of abnormal VV orientation was absolute for the same examiner (κ=1; P<0.05) and excellent between 2 examiners (κ=0.92; P<0.05). As for VV uncertainty the intrarater reliability was satisfactory (intraclass correlation coefficient, 0.836) but the inter-rater reliability was poor (intraclass correlation coefficient, 0.211).
  
  
  CONCLUSIONS
  The orientation of the VV is a highly reliable criterion, which may be used both in research and in routine clinical practice.
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.).
authors.forename: Celine
authors.initials: C
authors.lastname: Piscicelli
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.).
authors.forename: Julien
authors.initials: J
authors.lastname: Barra
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.).
authors.forename: Patrice
authors.initials: P
authors.lastname: Davoine
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.).
authors.forename: Anne
authors.initials: A
authors.lastname: Chrispin
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.).
authors.forename: Sylvie
authors.initials: S
authors.lastname: Nadeau
authors.affiliation: From the Clinique MPR-CHU, Grenoble, France (C.P., P.D., A.C., D.P.); Laboratoire de Psychologie et Neurocognition CNRS UMR 5105, Grenoble Université, Grenoble, France (C.P., D.P.); Laboratoire Vision, Action, Cognition, Université Paris Descartes, EA7326, Paris, France (J.B.); and École de réadaptation, Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Québec, Canada (S.N.). DPerennou@chu-grenoble.fr.
authors.forename: Dominic
authors.initials: D
authors.lastname: Pérennou
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010775:Photic Stimulation / Q000379:methods*; D015203:Reproducibility of Results; D016037:Single-Blind Method; D013028:Space Perception / Q000502:physiology; D020521:Stroke / Q000175:diagnosis* / Q000503:physiopathology
keywords: posture; rehabilitation; reliability; stroke