Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Research Article Dement Geriatr Cogn Disord 2010;29:55–60 DOI: 10.1159/000265542 Factor Analysis of the Brief Agitation Rating Scale in a Large Sample of Norwegian Nursing Home Patients Oskar H. Sommer a Øyvind Kirkevold b, c Milada Cvancarova d Knut Engedal a, e a Center for Old-Age Psychiatry Research, Innlandet Hospital Trust, Ottestad, b Norwegian Center for Dementia Research, Ageing and Health, Vestfold Mental Health Care Trust, Tønsberg, c Faculty of Health and Sport, University of Agder, Kristiansand, d Norwegian Radium Hospital, University of Oslo, and e Norwegian Center for Dementia Research, Center for Ageing and Health, Department of Geriatric Medicine, Ullevål, Oslo University Hospital, Oslo, Norway whereas increased severity of dementia and better func- tioning in activities of daily living were related to physically nonaggressive behavior. In addition, verbal agitation was positively related to a higher number of drugs being taken per day. Conclusions: The factor analyses confirmed that the Norwegian version of the BARS measures the clinically rele- vant dimensions of agitation in dementia. Copyright © 2010 S. Karger AG, Basel Introduction The measurement of behavioral symptoms in elderly patients with dementia has become an important area of research. This is due to the prevalence of disruptive and agitated behavior that puts a heavy strain on caregivers and poses a diagnostic, therapeutic and economic chal- lenge [1–4]. The prevalence of aggression and agitation, probably the 2 most challenging symptoms observed in nursing home populations, exceeds 20% [5, 6]. Instru- ments that measure aggression and agitation in patients with dementia should preferably have the potential to fa- cilitate the diagnosis of the dementia, monitor its course and evaluate the outcomes of therapeutic interventions [7] . A plethora of scales to measure aggression and agita- Key Words Dementia  Agitation  Aggression  Factor analysis  Cohen-Mansfield Agitation Inventory  Brief Agitation Rating Scale Abstract Background: Agitation and aggression are prevalent in de- mentia and put heavy strains on caregivers. Validated as- sessment tools measuring these symptoms are required to evaluate patients before therapy and during the follow-up period. Given the daily routine in nursing homes, abbrevi- ated instruments are preferable. The Brief Agitation Rating Scale (BARS) is a short form of the Cohen-Mansfield Agita- tion Inventory. Our aim was to examine the Norwegian ver- sion of the BARS by performing a factor analysis. Methods: The data came from 1,870 nursing home patients. The pri- mary caregivers were interviewed by research nurses using the Clinical Dementia Rating Scale, Lawton’s Physical Self- Maintenance Scale and the BARS. Results: The exploratory factor analysis of the BARS revealed 3 dimensions: physically aggressive behavior, physically nonaggressive behavior and verbal agitation. Linear regression analysis showed that re- duced functioning in activities of daily living was associated with physically aggressive behavior and verbal agitation, Accepted: November 30, 2009 Published online: January 27, 2010 Oskar H. Sommer Department of Geriatric Psychiatry Sykehuset Innlandet HF NO–2840 Reinsvoll (Norway) Tel. +47 4561 6442, Fax +47 6114 7785, E-Mail oskarsommer @ gmail.com © 2010 S. Karger AG, Basel 1420–8008/10/0291–0055$26.00/0 Accessible online at: www.karger.com/dem