Is carer management style associated with longitudinal functional decline in dementia?

Background: Various intrinsic (related to dementia) and extrinsic (not related to dementia) factors have been suggested to contribute separately to disability in people living with dementia (PLwD). Objective: To investigate if the combination of specific intrinsic and extrinsic factors at baseline is associated with longitudinal declines in activities of daily living (ADL) performance of PLwD at 12-month follow-up. Methods: 141 community-dwelling PLwD-carer dyads were assessed on their global cognition (ACE-III), apathy (CBI-R), carer management styles (DMSS), medical comorbidities (CCI), and ADL performance (DAD) at baseline, and for a subset of participants (n = 53), at 12-month follow-up. Multiple linear regression models were run to assess: 1) the relationships between PLwD’s DAD scores and the remaining variables at baseline and 2) whether these variables’ scores at baseline were associated with longitudinal change in the PLwD’s DAD scores. Results: At baseline, having lower ACE-III (β = 0.354, p < 0.001), higher CBI-R (β = –0.284, p < 0.001), higher DMSS criticism (β = –0.367, p = 0.013), lower DMSS encouragement (β = 0.370, p = 0.014), and higher CCI scores (β = –2.475, p = 0.023) were significantly associated with having lower DAD scores. The PLwD’s DAD scores significantly declined from baseline to follow-up (p < 0.001, d = 1.15), however this decline was not associated with the baseline scores of any of the independent variables. Instead, it was associated with declines in the PLwD’s ACE-III scores from baseline to follow-up (β = 1.021, p = 0.001). Conclusions: In our limited sample, cognitive changes seem to be the main factor underlying longitudinal decline in ADL performance for PLwD. Carer management styles appear associated with current ADL performance but not with longitudinal ADL decline.