Measurement of aggressive behaviors in dementia: comparison of the physical aggression subscales of the Cohen-Mansfield Agitation Inventory and the Ryden Aggression Scale.

One of the central issues in the development of research-based interventions for aggressive behavior (AB) in late-stage dementia is the provision of precise measurement of the major dependent variable, in this case, AB levels. To advance the nursing goal of evidence-based practice, this article presents the characteristics of two research instruments: the Cohen-Mansfield Agitation Inventory (CMAI) aggressive behavior subscale (CMAI-ABS) and the Ryden Aggression Scale (RAS) physically aggressive behavior subscale (RAS-PABS). A total of 282 shower bath events (which are most associated with AB) were observed for 107 nursing home residents with dementia in nine randomly selected nursing homes. Then, we compared the psychometric properties of the CMAI-ABS and the RAS-PABS. Moderate to substantial agreements between the two instruments were identified using Cohen's Kappa. A similar percentage of AB was found on both subscales. Similar items on both subscales, such as hitting and pushing, were moderately correlated. Overall, the study results support that the CMAI-ABS and RAS-PABS measure a single but multifaceted construct-physically aggressive behavior in dementia.