Date of Award

Summer 8-10-2021

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Public Health

First Advisor

Dr. Richard Rothenberg

Second Advisor

Dr. Katherine Masyn

Third Advisor

Dr. Sheryl Strasser


Frailty is a common geriatric syndrome characterized by decreased adaptability to stressors and increased vulnerability to adverse health outcomes. Frailty is not simply about ageing, but is where ageing has taken its toll. The risk of becoming frail, thus, is regulated by genetic and environmental factors via epigenetic mechanisms. This makes the older population considerably heterogeneous concerning frailty. Therefore, understanding frailty profiles and frailty trajectories is helpful for tailoring ageing health policies and interventions.

The dissertation consists of two studies to present complementary perspectives of frailty trajectories in the European older population. The studies conducted secondary analyses on data extracted from the Survey of Health, Ageing, and Retirement in Europe (SHARE). The first study compared frailty trajectories of older adults across eleven European countries and found universal parabolic age trends and country-specific cohort effects. The second study took a latent-class modeling approach to model the heterogeneity of frailty in the elderly population. The study found four distinct health profiles in the study population and a predominant tendency for state stability or dying over time. Noteworthily, there was a relatively noticeable proportion of transitions to a better health state, highlighting the potential for frailty reversal. In considering the gender effect, the two studies together reflect the long-described male-female health-survival paradox.

While the first study provides the population-level perspective of frailty trends, the second one examines the individual-level progression of frailty. The former provides a big picture of frailty trends, which can help assess and plan interventions. The latter can find its application in clinical practice, ageing research as well as policy applications. Given that data were drawn from nationally representative samples, our findings are greatly generalizable.


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