Periodic Reporting for period 3 - HEALIN (Healthy lifespan inequality: Measurement, trends and determinants)
Reporting period: 2023-05-01 to 2024-10-31
Despite its widespread use and popularity, life expectancy (LE) has two shortcomings. First, its definition only takes into consideration mortality levels, thus ignoring the health status of those who are still alive. Second, LE is an average that does not explain how the length of life is distributed across the population. These limitations have generated two strands of research (i.e. the study of ‘health expectancies’ (HE) and ‘lifespan inequality’ (LI)) that, so far, have developed independently from each other. The overarching objective of the HEALIN project is to bring together these research avenues into a coherent whole to obtain a more comprehensive understanding of contemporary population health dynamics. To attain this goal, I propose the new concept of ‘healthy lifespan inequality’ (HLI), which is designed to investigate the extent to which healthy lifespans are unequally distributed across the population.
The HEALIN project will (1) investigate the trends and determinants of HLI, (2) assess whether the specific ages and causes that drive changes in HLI are the same ones determining the changes in LE, HE and LI indicators, and (3) investigate how these indicators behave across and within countries and socio-economic groups. In addition, the project aims to make innovative contributions to the measurement of comorbidity and to our understanding of how the latter can, in turn, influence the measurement of health expectancy and healthy lifespan inequality. To attain these objectives, the project will develop path-breaking analytical methods inspired in the models applied for the study of inequality and multidimensional poverty. In addition to traditional socio-economic and health data sources, the project will complementarily draw from the vastly underutilized health registers for the population in Catalonia (7.5 million residents). Their large size and micro-level design allow for the investigation of trends in HLI and comorbidity with unprecedented detail
The HEALIN project will (1) investigate the trends and determinants of HLI, (2) assess whether the specific ages and causes that drive changes in HLI are the same ones determining the changes in LE, HE and LI indicators, and (3) investigate how these indicators behave across and within countries and socio-economic groups. In addition, the project aims to make innovative contributions to the measurement of comorbidity and to our understanding of how the latter can, in turn, influence the measurement of health expectancy and healthy lifespan inequality. To attain these objectives, the project will develop path-breaking analytical methods inspired in the models applied for the study of inequality and multidimensional poverty. In addition to traditional socio-economic and health data sources, the project will complementarily draw from the vastly underutilized health registers for the population in Catalonia (7.5 million residents). Their large size and micro-level design allow for the investigation of trends in HLI and comorbidity with unprecedented detail
During the first 30 months, we have made considerable progress in several fronts of the project. To begin with, we have already completed and published the “foundational” or background paper lying down some of the key concepts to be analyzed during the project. They are included in the paper “On the measurement of healthy lifespan inequality”, which has been published in Population Health Metrics ( https://doi.org/10.1186/s12963-021-00279-8 ).
The project involves the exploitation of longitudinal and cross-sectional data. As regards the analysis of longitudinal data, we are currently in the middle of the process of requesting and accessing the health records for the populations of Catalonia and Denmark. Because of statistical confidentiality issues with the health registers, this is a long and complicated procedure involving many steps. Regarding the Catalan health registers we have already framed the cohorts that will be analyzed and the diseases that will be studied, and in the next couple of months we should be able to start with the first longitudinal analyses. As regards the access to the Danish health registers, we have already signed a collaboration agreement between the Center for Demographic Studies and the University of Southern Denmark (who will provide access to the registers). In the coming months, access to the Danish data will be granted as well.
An important part of the project involves the exploitation of cross-sectional data to generate our new population health indicators. In this regard, we have already completed our analyses in several studies. One of them involves the study of health inequalities in contemporary Spain across education groups and subnational regions, which has already been published in the journal Population, Space and Place. Another one studies health inequalities in thirty European countries both in 2005 and 2015, which we have recently completed and is ready to be submitted for publication. In addition, we have completed another paper estimating our new population health indicators at a global scale taking advantage of the “Global Burden of Disease (GBD)” database. With such database, we have been able to extend our estimates for more than 200 countries and territories all over the world, since 1990 to the present date, for women and men separately. The paper is currently under review in a high-impact journal.
Another strand of research we have been working on in the project is the study of cause-of-death diversity and disease heterogeneity in contemporary societies. We have already completed two papers. One of them investigates the measurement of cause-of-death diversity in those settings where individuals can die from several causes of death simultaneously. It has already been accepted in Demography, the top journal in the field. Another one takes advantage of the GBD database, and investigates the levels, trends and determinants of cause-of-death diversity from a global perspective (including 204 countries and territories from 1990 to 2019). Currently, it is being reviewed in a high-impact journal.
During these months, our results have been presented at several international conferences (like the ones organized by the “European Association for Population Studies” (EAPS), the “Population Association of America” (PAA), the “International Union for the Scientific Study of Population” (IUSSP) or the “International network on health expectancies and the disablement process” (REVES)) and workshops (e.g. the ones organized by the “EAPS Health, Morbidity and Mortality Working Group”, the “New Perspectives on Lifespan Inequality” organized by the Universities of Oxford, Southern Denmark and Tel Aviv, or the “Climbing Mortality Models” seminar organized by the Universities of Bocconi and Padova). Because of the limitations imposed by the pandemic, many of them have been in held in an online/virtual format.
The initial results of our research have been published in top journals, like the Proceedings of the National Academy of Sciences (PNAS), Population Health Metrics, the Journal of the Royal Statistical Society (Series A), or Demography. Several other papers are currently under review and/or in different stages of the publication process.
The project involves the exploitation of longitudinal and cross-sectional data. As regards the analysis of longitudinal data, we are currently in the middle of the process of requesting and accessing the health records for the populations of Catalonia and Denmark. Because of statistical confidentiality issues with the health registers, this is a long and complicated procedure involving many steps. Regarding the Catalan health registers we have already framed the cohorts that will be analyzed and the diseases that will be studied, and in the next couple of months we should be able to start with the first longitudinal analyses. As regards the access to the Danish health registers, we have already signed a collaboration agreement between the Center for Demographic Studies and the University of Southern Denmark (who will provide access to the registers). In the coming months, access to the Danish data will be granted as well.
An important part of the project involves the exploitation of cross-sectional data to generate our new population health indicators. In this regard, we have already completed our analyses in several studies. One of them involves the study of health inequalities in contemporary Spain across education groups and subnational regions, which has already been published in the journal Population, Space and Place. Another one studies health inequalities in thirty European countries both in 2005 and 2015, which we have recently completed and is ready to be submitted for publication. In addition, we have completed another paper estimating our new population health indicators at a global scale taking advantage of the “Global Burden of Disease (GBD)” database. With such database, we have been able to extend our estimates for more than 200 countries and territories all over the world, since 1990 to the present date, for women and men separately. The paper is currently under review in a high-impact journal.
Another strand of research we have been working on in the project is the study of cause-of-death diversity and disease heterogeneity in contemporary societies. We have already completed two papers. One of them investigates the measurement of cause-of-death diversity in those settings where individuals can die from several causes of death simultaneously. It has already been accepted in Demography, the top journal in the field. Another one takes advantage of the GBD database, and investigates the levels, trends and determinants of cause-of-death diversity from a global perspective (including 204 countries and territories from 1990 to 2019). Currently, it is being reviewed in a high-impact journal.
During these months, our results have been presented at several international conferences (like the ones organized by the “European Association for Population Studies” (EAPS), the “Population Association of America” (PAA), the “International Union for the Scientific Study of Population” (IUSSP) or the “International network on health expectancies and the disablement process” (REVES)) and workshops (e.g. the ones organized by the “EAPS Health, Morbidity and Mortality Working Group”, the “New Perspectives on Lifespan Inequality” organized by the Universities of Oxford, Southern Denmark and Tel Aviv, or the “Climbing Mortality Models” seminar organized by the Universities of Bocconi and Padova). Because of the limitations imposed by the pandemic, many of them have been in held in an online/virtual format.
The initial results of our research have been published in top journals, like the Proceedings of the National Academy of Sciences (PNAS), Population Health Metrics, the Journal of the Royal Statistical Society (Series A), or Demography. Several other papers are currently under review and/or in different stages of the publication process.
We have convincingly argued about the need to complement currently existing measures of population health (like life expectancy, or healthy life expectancy) with new indicators that measure the extent to which the healthy lifespans of individuals are equally or unequally distributed (the so-called “Healthy Lifespan Inequality” indicators). These indicators should greatly improve our understanding of contemporary health dynamics. Until the end of the project, we expect to (i) be able to generate estimates of these indicators across most world countries, (ii) compare their behavior vis-à-vis currently existing measures of population health, and (iii) document and understand the main forces underlying the process of change for these population health indicators.