Relationship between measures of dementia severity and observation of daily life functioning as measured with the Assessment of Motor and Process Skills (AMPS)

Abstract

Background: Cognitive impairment is mostly regarded as the core symptom of dementia, but several other domains (such as daily functioning) are equally relevant to assess the severity of dementia. The relationship between these domains is unclear. The Assessment of Motor and Process Skills (AMPS) is a relatively unexplored instrument in people with dementia, measuring severity by direct observation.

Objective: To study the relationship between the AMPS and scores on several commonly used outcome measures for the assessment of dementia severity, and to examine the possible influence of neuropsychiatric symptoms on these relationships in patients with cognitive disorders.

Methods: Cross-sectional data of 118 patients with cognitive disorders were used; data on cognition (Mini-Mental State Examination, MMSE; CAMCOG), global severity (Global Deterioration Scale, GDS), daily life functioning (Instrumental Activities of Daily Living, IADL), and neuropsychiatric symptoms (Neuropsychiatric Inventory, NPI) were collected and analyzed using correlation and regression analyses. Different combinations of the severity measures were tested for their ability to predict the AMPS process ability scores.

Results: Scores on the MMSE, CAMCOG and GDS were moderately associated with the AMPS process ability score. These measures explained between 27 and 44% of the variance in the AMPS score. The presence of apathy influenced the association between the cognitive measures and the AMPS score.

Conclusion: Commonly used measures of dementia severity are only moderately associated with observation of performance on daily activities. This underlines the need for direct observation of daily activities in dementia patients. This relationship between several approaches of assessing dementia severity needs further study.