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Behavioural Neurology
Volume 2016, Article ID 3123402, 7 pages
Research Article

Orofacial Pain during Mastication in People with Dementia: Reliability Testing of the Orofacial Pain Scale for Non-Verbal Individuals

1Department of Oral Health Sciences, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, Netherlands
2Department of Clinical Neuropsychology, VU University Amsterdam, Van der Boechorstraat 1, 1081 BT Amsterdam, Netherlands
3Department of General Practice & Elderly Care Medicine, VU University Medical Center (VUmc), Van der Boechorststraat 7, 1081 BT Amsterdam, Netherlands
4Department of Public Health and Primary Care (PHEG), Leiden University Medical Center (LUMC), Hippocratespad 21, 2300 RC Leiden, Netherlands

Received 24 November 2015; Revised 17 January 2016; Accepted 18 January 2016

Academic Editor: Marina De Tommaso

Copyright © 2016 Merlijn W. de Vries et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objectives. The aim of this study was to establish the reliability of the “chewing” subscale of the OPS-NVI, a novel tool designed to estimate presence and severity of orofacial pain in nonverbal patients. Methods. The OPS-NVI consists of 16 items for observed behavior, classified into four categories and a subjective estimate of pain. Two observers used the OPS-NVI for 237 video clips of people with dementia in Dutch nursing homes during their meal to observe their behavior and to estimate the intensity of orofacial pain. Six weeks later, the same observers rated the video clips a second time. Results. Bottom and ceiling effects for some items were found. This resulted in exclusion of these items from the statistical analyses. The categories which included the remaining items () showed reliability varying between fair-to-good and excellent (interobserver reliability, ICC: 0.40–0.47; intraobserver reliability, ICC: 0.40–0.92). Conclusions. The “chewing” subscale of the OPS-NVI showed a fair-to-good to excellent interobserver and intraobserver reliability in this dementia population. This study contributes to the validation process of the OPS-NVI as a whole and stresses the need for further assessment of the reliability of the OPS-NVI with subjects that might already show signs of orofacial pain.