A Demographically Motivated Index of within-Population Health Inequality

Rustam Tursun-zade , University of Basque Country
Tim Riffe, University of Basque Country
Alyson van Raalte, MPIDR

Background: Much has been done to measure within-population lifespan inequality, but less is known about within-population health inequality. Attempts to develop an incidence-based version of such an index are scarce compared to those for prevalence-based indices. Methods: Inspired by e-dagger, we propose a new incidence-based index of within-population health inequality. Our index is neatly decomposable into the contributions of different life transitions to total inequality. We calculate transition probabilities from SHARE data for Spain using the msm package and derive the fundamental matrix from which we obtain all quantities required to calculate the index. Results: We offer a demographically motivated, interpretable, and additively decomposable index of incidence-based within-population health inequality, which (i) does not assume the independence of survival and health status and (ii) distinguishes between reversible and irreversible conditions. We relate this index to classic lifespan inequality measures and entropy. As is the case for e-dagger, contributions to our index from mortality are necessarily positive. At the same time, transitions between health states can either increase or decrease inequality depending on the inequality measure. Conclusion: We consider our index demographically motivated because it can be verbalised as the expected number of years gained or lost of years lived in a state due to each transition. This is the multistate analogue of lifetable e-dagger, and we conjecture that it will also relate to a multistate notion of lifetable entropy.

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 Presented in Session P6. Health, Mortality, and Ageing 2