Healthy longevity in the 21st century: Leveraging longitudinal microdata to explore macro trends in healthy life expectancy

Does increasing life expectancy mean fewer years spent in poor health? For cohorts born in the late 19th and early 20th centuries in high-income countries like the United States, later-born cohorts did appear to live longer and to live longer in better health than earlier-born cohorts. However, for cohorts born since the Second World War, the connection between longer lives and better health appears less straight-forward. In the United Kingdom, later-born post-war cohorts have a higher prevalence of poor physical and mental health at the same age compared to earlier-born cohorts. Most studies on recent trends on healthy life expectancy use pseudo-cohorts constructed from cross-sectional data. This can limit our ability to understand the mechanisms driving between-cohort differences in health expectancies since they do not reflect the lived experience of any real set of individuals. Data from longitudinal studies could help to better understand what is driving inter-generational differences in health expectancies, allowing us to observe how individuals progress through different health states throughout their lives.

The aim of this PhD is to leverage longitudinal micro-data from a series of cohort studies to improve our understanding of recent trends in healthy life expectancy in high-income countries, with a special emphasis on the United Kingdom. The project will assess how the age of onset of disease has changed across successive generations born since the Second World War, and what these changes might mean for society and population health as cohorts in early and mid-adulthood reach older ages. It will also explore the extent to which between-cohort differences in healthy life expectancy result from 'objectively' worse health, by leveraging biomarker and linked administrative data from the healthcare system, and how much might be driven by changing perceptions and expectations of what it means to be healthy in the 21st century.