EARLY DETECTION OF COGNITIVE IMPAIRMENT IN OLDER ADULTS: TECHNOLOGY USE IN FUNCTIONAL ASSESSMENT

Abstract

Introduction: Effective assessment of functional capacity, such as the ability to use technology, is vital to recognising the earliest signs of cognitive decline in neurodegenerative disorders. Yet, commonly used assessments of functional capacity lack cultural and technological relevance, are not sensitive to early change, and are measured sporadically. In this PhD, I aimed to improve methods of measuring and detecting functional impairment in people with early cognitive decline by i) providing a culturally adapted measure of instrumental activities of daily living (IADL) for use in the UK, and ii) exploring the potential of computer-use behaviours as an objective digital biomarker of functional and cognitive decline. Methods: Four studies are presented. In study A, the Amsterdam IADL Questionnaire (A-IADL-Q) was culturally adapted for use in the UK in three iterative steps involving 190 stakeholders. Study B was a pilot study to assess the feasibility and acceptability of monitoring computer-use behaviours. In study C, semi-directed computer tasks and cognitive and functional assessments were completed by older adults with cognitive impairment (n = 20) and cognitively healthy controls (n = 24). In study D, people with subjective cognitive decline (SCD) or mild cognitive impairment (MCI) (n = 32) took part in a longitudinal study that used bespoke software to monitor in-home computer-use behaviours lasting approximately nine months. Results: In study A, iterative modifications to the A-IADL-Q resulted in a 55-item adapted version appropriate for UK use (A-IADL-Q-UK). New and revised items performed well; all activities were perceived as more difficult by at least one participant per item and four new items correlated with the total score. An exploratory analysis of convergent validity found correlations with cognitive and functional abilities. Study B showed that monitoring computer-use was feasible and acceptable. In study C, cognitively impaired participants displayed more frequent pauses, slower typing, and a higher proportion of mouse clicks compared to cognitively healthy controls. These behaviours were significantly associated with performance on selected memory and functional assessments. In study D, no change in computer-use behaviour was detected over the study period. Computer use behaviours were associated with recall, recognition, task switching, task inhibition and visual attention. People with MCI had slower keystroke speed and used the computer less than people with SCD. Conclusion: This PhD has made an important contribution to the literature by taking a step forward in the way technology is incorporated into functional measurement. Firstly, the A-IADL-Q-UK informant report version and new self-report version, incorporates a range of culturally relevant activities including technology use. Secondly, the measurement of computer use behaviours shows promise as a potential novel digital biomarker to measure cognitive and functional ability. Future work will be to expand the cultural relevance of the A-IADL-Q-UK for multicultural groups in the UK and beyond and to further investigate the relationship between computer use and functional ability in a larger and more diverse sample, with the ultimate aim of finding a pragmatic, unobtrusive and continuous digital biomarker for the earliest detection of functional and cognitive change.

Date of Award	1 Aug 2021
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Daniela Montaldi (Supervisor) & Laura Brown (Supervisor)