Application of Actigraphy to the Measurement of Neuropsychiatric Symptoms of Agitation in Dementia

Abstract

This thesis evaluates the application of actigraphy to the measurement of neuropsychiatric symptoms (NPS) of agitation in older adults with dementia. There are increasing numbers of older adults with dementia and management of NPS is an important aspect of providing care for this population. This thesis examined the correlation between actigraphic measures and questionnaire-based measures of NPS, including the Cohen-Mansfield Agitation Inventory (CMAI) and other measures of NPS. The actigraphic characteristics of individuals with high and low levels of agitation were described along with an assessment of the feasibility of actigraphy for measuring NPS of agitation. A total of 15 individuals with dementia residing in geriatric psychiatry inpatient units in hospital and in long-term care (LTC) facilities were included in the study. Participants wore an actigraph device on their non-dominant wrist for seven consecutive days. Informant-rated NPS measures were completed through interviews with nursing staff familiar with participants. Participants were dichotomized into groups according to agitation status as measured by a cutoff score of ≥50 on the CMAI indicating high agitation. The mean actigraph wear time for the total sample was 6.2 days (SD=1.5). Significant positive correlations were found between overall motor activity as measured by actigraphy mean motor activity (MMA) counts and the CMAI total scores for 24-hour (r=0.70, P=0.004), daytime (r=0.75, P=0.001), and evening (r=0.72, P=0.003) time periods, while nighttime MMA counts were not correlated with CMAI scores (r=-0.03, P=0.917). Significant positive correlations were found between MMA counts and CMAI verbal and non-aggressive physical agitation subscores. Additionally, patients with high CMAI scores had higher levels of 24-hour activity (mean MMA = 169.6, SD=89.4) than patients with low CMAI scores (mean MMA=78.6, SD=35.4, P=0.016). In conclusion, actigraphy appears to be feasible method of measuring some NPS. Actigraphic measures are strongly correlated with questionnaire-based measures of agitation and higher levels of agitation are associated with higher daytime and evening motor activity as measured by actigraphy. Individuals with high levels of agitation can be distinguished from individuals with low agitation using actigraphy. However additional studies are required to further understand the application of actigraphy to the measurement of these important symptoms.