Identification of eating, drinking and swallowing difficulties for people living with early-stage dementia: a systematic review

Background
The prevalence of dementia is increasing, bringing a range of challenges, such as eating, drinking and swallowing (EDS) difficulties, that are associated with aspiration, which can be fatal. Early identification of EDS difficulty in early‐stage dementia could prevent complications, but reliable indicators are needed to help develop pathways to support the diagnosis. Previous reviews of this area require updating. Aims: To identify reliable and clinically measurable indicators of EDS difficulty used in early‐stage dementia.

Methods & Procedures
A systematic search was conducted using common databases (MEDLINE, EMBASE and PsychInfo). Articles reporting indicators of EDS difficulty in early‐stage dementia or mild cognitive impairment were included. The reliability of included studies was critically appraised using the risk of bias tools. Study outcomes were narratively reviewed by considering the reliability, clinical measurability and applicability of EDS indicators to early‐stage dementia.

Outcomes & Results
Initial searches returned 2443 articles. After removing duplicates, limiting to English language and human studies, 1589 articles remained. After reviewing titles, 60 abstracts were reviewed, yielding 18 full‐text articles. A total of 12 articles were excluded that did not report at least one indicator of EDS difficulty in early‐stage dementia, or where the reported association was not strong. Six included studies that reported eight indicators of EDS difficulty in early‐stage dementia (four studies including people with Alzheimer's disease). On the balance of measurability, reliability and applicability, the most promising indicators of EDS difficulty were: delayed oral transit, rinsing ability, sarcopenia and polypharmacy. Additional, less reliable and applicable indicators included: always opened lips and non‐amnestic mild cognitive impairment, especially in men. The delayed pharyngeal response is subjectively measured when instrumental assessment is not available and the ‘candy sucking test’ cannot be recommended because there is an inherent choking risk.

Conclusions & Implications
EDS difficulty in early‐stage dementia can be highlighted by indicators that could be combined to create enhanced pathways to support the early identification of EDS difficulties for people living with early‐stage dementia with a view to preventing complications and facilitating informed discussions regarding wishes in the event of further deterioration. Exploring the experiences of people living with dementia and their families’ perspectives on potential indicators of EDS difficulty may add to the existing evidence base.

WHAT THIS PAPER ADDS
What is already known on the subject
Early identification of EDS difficulty in early‐stage dementia may prevent complications, but more reliable and clinically measurable indicators of EDS difficulty are needed to help develop pathways to support diagnosis.

What this paper adds to existing knowledge
A comprehensive range of studies related to EDS identification in early‐stage dementia have been selected and reviewed. Across six included studies, the most promising indicators of EDS difficulty in early‐stage dementia included delayed oral transit, poor rinsing ability, presence of sarcopenia and polypharmacy.

What are the potential or actual clinical implications of this work?
This study could help to develop pathways to support the early identification of EDS difficulties for people living with early-stage dementia with a view to preventing complications and facilitating informed discussions regarding wishes in the event of further deterioration.