Frailty is an important concept capturing age-related declines in various aspects of physical condition and mental capacity. Previous research has developed measures of frailty that ‘count’ the number of age related declines in physical and mental functioning with higher counts indicating higher levels of frailty. We know that those with higher frailty scores are more likely to die early, to be admitted to a care home or to suffer a fall. Research has also shown stark inequalities in frailty among older people. For example, in England, we observe a ten-year difference in the level of frailty such that an 85 year-old in the richest wealth fifth of the population has a similar level of frailty compared to a 75 year-old in the poorest fifth of the population. What we do not know is whether the nature of frailty is the same among these two groups. Do we see similar patterns of age-related declines in physical condition and mental capacity and wellbeing for the rich and the poor? Or do the differences in levels of frailty come with different sets of underlying conditions? It is these questions that this PhD addresses testing whether the specific underlying conditions of frailty vary according to wealth, age, gender or the country a person lives in. Understanding of the nature of frailty in later life better enables us to care for an ageing population and develop strategies to deal with the stark inequalities observed in frailty and by extension life expectancy.
The project will use the English Longitudinal Study of Ageing and its partner studies in other countries to assess whether the patterns of age-related physiological and cognitive declines used within survey measure of frailty, vary across national contexts and within England according to individual characteristics/circumstances. The studentship is part of the Advanced Quantitative Methods steer and views frailty as a latent construct which is potentially complex and multidimensional and uses Bayesian Item Response models to analyse this complex structure in different population groups and national settings.