Assessment of agitation in elderly patients with dementia: correlations between informant rating and direct observation

BACKGROUND: Assessment of behavior problems in elderly persons with dementia is important for understanding and managing those behaviors. The most common method for assessing agitation is the use of informant ratings; however, these ratings may be affected by staff bias, inaccurate or insufficient memory, or stress. An alternative method is direct observation, which is more objective, but very costly and necessitates time sampling, thereby limiting the period covered by the assessment. To date, little research attention has been given to the degree to which these two methods converge. METHODS: In the present study, 175 elderly persons with dementia who manifested problem behaviors were recruited from 11 nursing home facilities in Maryland. The average age for the participants was 87 years; 78% were female. Two methods were employed for assessing agitation: the Agitated Behaviors Mapping Instrument (ABMI), which is based upon direct observations, and the Cohen-Mansfield Agitation Inventory (CMAI), which is a frequency rating scale completed by a formal caregiver. The ABMI and CMAI contain some identical items for tapping behavior problems. RESULTS: Data analysis revealed significant Pearson correlations between identical items on the two assessment instruments, as well as significant correlations of summary measures based on these different instruments, demonstrating a strong convergence between informant ratings and direct observations. CONCLUSIONS: Informant ratings can achieve moderate agreement with direct observation when valid instruments and informants are used.