A randomised controlled trial of hearing and vision support in dementia: Protocol for a process evaluation in the SENSE-Cog Trial

Abstract

Background: Optimising hearing and vision function may be important in improving a range of outcomes for people living with dementia (PwD) and their companions. The SENSE-Cog cross-national randomised controlled trial (RCT) is evaluating the effectiveness of a sensory intervention (SI) to improve quality of life for PwD with concurrent hearing and/or vision impairment, in five European countries. To ascertain how or why the intervention will, or will not, achieve its outcomes, we have designed a process evaluation to explore potential discrepancies between expected and observed outcomes. This will also help us to understand how context may influence the outcomes. Here we describe the protocol for this process evaluation, which is embedded within the RCT. Methods and analysis: We will use a mixed method approach with a theoretical framework derived from the UK Medical Research Council's' guidance on process evaluations. It will include the following: (1) evaluating how key aspects of the intervention will be delivered, which will be important to scale the intervention in real world populations; (2) characterising the contextual issues, which may shape the delivery and the impact of the intervention in different countries; and (3) investigating possible causal mechanisms through analyses of potential moderators and mediators. To avoid bias, we will analyse the process data before the analysis of the main effectiveness outcomes. Discussion: This evaluation will provide insight into how the complex SENSE-Cog SI will be tailored, enacted and received, across the different European contexts, all of which have unique health and social care economies. The findings will provide insight into the causal mechanisms effecting change, and will determine whether we should implement the intervention, if effective, on a wider scale for PwD and concurrent sensory impairment. Trial registration number: ISRCTN17056211. Registered on 19 February 2018.

The impact of hearing impairment and hearing aid use on progression to mild cognitive impairment in cognitively healthy adults: An observational cohort study

“…exploring the relationship between auditory impairment and cognition are ongoing. [25][26][27] Although there have been many studies that included cognitively normal adults as part of the study sample, when investigating the association between hearing loss and cognitive decline or dementia as an outcome, few studies have examined the impact of hearing impairment and hearing aid use on incident MCI. 28,29 MCI is important to consider as an earlier outcome on the trajectory of cognitive decline that could further improve our ability to identify which early detection measures, or combination of measures, obtained among individuals increase or decrease the likelihood of progression from normal cognition to the onset of clinical symptoms associated with cognitive impairment.…”

“… 24 Few RCTs further exploring the relationship between auditory impairment and cognition are ongoing. 25 , 26 , 27…”

“…So far, the preliminary results from the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study demonstrated a significant effect of hearing aid use on composite memory scores after 6 months of follow‐up; however, improvement in other cognitive outcomes (language, executive function, global function) was not observed 24 . Few RCTs further exploring the relationship between auditory impairment and cognition are ongoing 25–27 …”