Frailty in older adults in Northern Ireland

: prevalence, characteristics and mortality risk

Abstract

Background:
Populations around the world are rapidly ageing, increasing researchers and policy-makers interest in healthy ageing. Of the conditions which affect older adults, the frailty syndrome has been highlighted as a key concern, as it is characterised by an increased likelihood of negative outcomes. Despite preliminary evidence of a high prevalence of frailty in Northern Ireland, there is a lack of research focusing on this population.

Aim:
To provide an in-depth answer to the question ‘’How does frailty affect the 50 years and older population of Northern Ireland?’’ Focusing in particular on the prevalence, associated characteristics, and mortality risk of frail older adults as well as conducting a parallel exploration into frailty measurement.

Methods:
This thesis centered on secondary analysis of Wave 1 of the Northern Ireland Cohort for the Longitudinal Study of Ageing (or NICOLA study), which provides a sample of 8,500 individuals who are representative of the Northern Ireland population aged over 50. An accumulation deficits frailty index containing 30 items was used, alongside two objective indicators (grip strength and timed up and go) to assess the differences between objective and subjective frailty measures. In Chapter 4, the NICOLA sample was linked with mortality data to allow for longitudinal analysis of the relationship between frailty status and mortality risk. Wave 1 of the Irish Longitudinal Study on Ageing (TILDA), was also used in Chapter 5 to provide context and comparisons for the NICOLA findings and a combined all-Ireland perspective on frailty.

Results:
Older adults in Northern Ireland were found to have a high prevalence of frailty, with 29.0% identified as frail using the 30-item frailty index. This prevalence of frailty was higher both than previous pooled estimates within the literature and comparative counterparts in the Republic of Ireland (16.0%). However, the proportion of older adults identified as frail differed significantly depending on the measure used, with low overlap and agreement found between the 30-item frailty index, grip strength, and timed up and go. The likelihood of frailty was consistently increased with certain characteristics including older age, sex, and socio-economic status. All measures significantly increased the risk of mortality and contributed even after adjustment for each other leading to the conclusion that these measures are capturing different aspects of the frailty syndrome. Other key findings include a high prevalence in middle age (one-fifth of 50-59-year-olds) and a lack of natural frailty cut points in mortality risk.

Conclusion:
This study provides the most in-depth exploration of frailty in the older population of Northern Ireland to date and offers evidence that frailty is a particularly important public health concern, given its high prevalence rates and association with increased mortality risk. It is hoped that these findings have the potential to impact policy and not only improve the lives of those living with frailty today, but better plan and prepare for the older population of the future.

Thesis is embargoed until 31 July 2024.

Date of Award	Jul 2023
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Northern Ireland Department for the Economy
Supervisor	Dermot O'Reilly (Supervisor) & Sharon Cruise (Supervisor)