Gender inequality in healthy ageing: a study of the English older population over a decade

This thesis investigates gender inequalities in healthy ageing among the older English population, using data from the English Longitudinal Study of Ageing. The research aims were achieved by completing the following steps: (i) healthy ageing was intended as advancing to the later stages of the life course without disability; where disability was first theoretically conceptualized and then measured using severity levels that were identified empirically; (ii) gender inequalities in healthy ageing were assessed by studying whether the association between disability and mortality observed over the course of a decade differed between men and women; and (iii) disability and mortality were combined into a summary measure of population health -disability-free life expectancy- in order to estimate how expectancies of healthy life have changed over a decade across the two genders. The work is structured in four papers, denoted Research Paper I-IV. Research Paper I, a systematic literature review of studies analysing inequalities in health expectancy among the older population, inspired the direction taken by this thesis, as it identified gaps and open questions to be addressed to aid the understanding of the dynamics of healthy ageing. Research Paper II attempted to develop an approach to answer some of these questions. First, a solid and theoretically grounded definition of disability was proposed, based on the WHO's International Classification of Functioning Disability and Health (ICF), and in contrast to the data-dependent (and therefore heterogeneous) measures used in the literature. Then, using this definition, explanations of the gender paradox in health and mortality were attempted by analysing whether the association of disability with mortality differed between women and men over the period for which data were available (2002-2012). In Research Paper III the definition of disability elaborated in Research Paper II was used to foster and advance the debate on the usefulness and relevance of adopting a finer categorization of disability, and discuss why it is important to go beyond a binary classification, and to identify the appropriate number of disability levels that is most useful for research purposes. Based on these conclusions, the final aim of this thesis was accomplished in Research Paper IV, which studied the trends in disability-free life expectancy in England over the last decade, comparing the changes experienced by men and women at each severity level of disability. The collective findings of this thesis highlight the importance of defining disability in a consistent and comprehensive way as well as considering different severity levels. This work provides robust empirical evidence for theories of population health change over a decade in the English setting, with gender differences in healthy ageing, and directions of population health changes, found to vary across disability levels.