Determinants of Longevity and Ageing in Good Health (DELAG)

Website of Dr. Marc Luy and his Research Team

Research Profile

The main objective of our research is to disentangle the complex causation of healthy ageing. We want to better understand the factors and causal mechanisms that enable some (groups of) people to live longer and healthier than others. Existing knowledge about the central drivers of healthy ageing is still incomplete. This partial knowledge is like a huge jigsaw puzzle of which many—albeit not all—pieces are at hand, but without knowing for most of them the right position in the big overall picture. Our research is organized toward the aim to add key pieces to this puzzle, which will contribute to a better understanding of the determinants of healthy ageing. Four specific characteristics distinguish our studies inside the community of health and mortality researchers:

  1. Concentration on differentials in health and longevity with a particular focus on quasi-experimental settings,
  2. Introduction of new hypotheses to explain extent and trends of differentials in health and longevity,
  3. Estimation of levels and differentials in health and longevity in terms of life years,
  4. Application-oriented development of innovative methods to estimate life expectancy (LE) and health expectancy (HE) for specific subpopulations.

We focus our research on differentials in health and longevity because we believe that when we understand why a specific subpopulation lives longer and healthier than another, we learn a lot about the general mechanisms which drive healthy ageing. In our studies of these differentials it is always important for us to extend the state-of-the-art and to think in a new direction. This is why our research is also characterized by the introduction of new hypotheses to explain the mechanisms behind health and mortality differentials. Most of our studies use life years (overall and separated into specific health states) as main outcome measure. The reason for our concentration on this indicator is that for many questions and most users of studies on health and mortality—such as public health policy officials—differences in life years are more important and informative than differences in standardized death rates or relative risks which are usually used in this context. The estimation of LE and HE for specific subpopulations often requires analytical innovations because the existing methods do not permit the derivation of such estimates with the available data. More information about these works can be found in our research highlights.

The long-term vision that drives our research is to develop a general causation model of differentials in health and longevity. From the results of our previous studies we expect that all kinds of differentials are strongly linked, with gender and socioeconomic status (SES)—including human capital, occupation, wealth, prestige, power and social connections—being the central layers which bind the single causation elements together and drive the overall mechanisms. The model is supposed to (i) identify the main micro-level risk factors of health and mortality, (ii) explain how these produce differentials between specific subpopulations on the meso-level (and how they interact with them), and (iii) unveil the mechanisms through which these subgroups determine the level and trend of health and mortality of the total population (macro-level). The model will be an important key toward a comprehensive understanding of the main determinants of "successful aging", i.e. the factors building the grounds for a long life with a shortest possible period spent with limiting and disabling health impairments.

Our research is based on external as well as self-collected data. The former include macro level data like the Human Mortality Database and the WHO Mortality Database as well as micro-level survey data, e.g. SHARE, EU-SILC (Survey of Income and Living Conditions), SOEP (German Socio-Economic Panel), DEAS (German Ageing Survey), and GEDA (German Health Interview Survey). Our own data collection is conducted in the context of the German-Austrian Cloister Study. This project and the data collection can be divided into three closely related sub-projects. The first is the "Catholic Order Members Mortality Study" (COMMS) which is based on the life dates of around 18,000 individuals collected directly in the cloister archives. This project has been extended by the "Ageing Study of Catholic Order Members" (ASCOM) to investigate the health of this specific subpopulation by a multi-wave survey with a sample of around 1,200 nuns and monks. Finally, we study the individual and societal consequences of "Ageing in an Aged Society" (AGAS) which the religious communities experienced already to an extent the general societies will never do. There are only two comparable projects which are both located in the United States: the Nun Study at the University of Minnesota in Minneapolis and the Religious Order Study at the Rush University Medical Center in Chicago. Both are focusing on the study of Alzheimer’s disease, what makes our Cloister Study with its broader social-scientific approaches to study the individual- and context-level drivers of health and longevity worldwide unique.
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