Inter- and Intra-Rater Reliability of the Visual Vertical in Subacute Stroke

I have no clue on this, but why use this type of test to determine correlation of posture problems? Why not use something totally objective like location of the damage?
http://stroke.ahajournals.org/content/early/2015/05/28/STROKEAHA.115.009610.abstract?sid=5ac4f2f8-8678-4701-9cb0-482e6f1146cb

1. Celine Piscicelli, MS,

1. Julien Barra, PhD,

1. Patrice Davoine, MD,

1. Anne Chrispin, MD,

1. Sylvie Nadeau, PhD and

1. Dominic Pérennou, MD, PhD

+ Author Affiliations

1. 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.).

1. Correspondence to Dominic Pérennou, MD, PhD, Clinique MPR- CHU, Laboratoire de Psychologie et Neurocognition CNRS-UMR 5105, Grenoble Université, Grenoble, France. E-mail DPerennou@chu-grenoble.fr

Abstract

Background and Purpose—Visual vertical (VV) has been being increasingly used 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.