Tuesday, December 3, 2013

Peak Health?

Eurostat data for healthy life years expectancy (HLYE) in some European countries, as reported in a paper uploaded on arXiv in 2013 by Ugo Bardi and Virginia Pierini. Measuring "health" carries large uncertainties, but these data hardly conform to the common perception of an increasingly better health condition in Europe.

We all know that we are living longer lives, at least in rich countries. But are we also living healthier lives? This is not so evident. On the contrary, sometimes, it seems that the elderly are paying dearly for their extra years of life in terms of all sorts of chronic illnesses and handicaps.

However, this is just a qualitative perception that should be supported by data if we have to consider it as worth of attention. Unfortunately, the concept of "health" is rather difficult to define and measure; nevertheless there exist data reporting a parameter called "Healthy Life Expectancy" or "Healthy Life Years Expectancy" (HLYE) that measure the expected number of "disability free" years of one's life.

The analysis of these data is the subject of a paper that myself and my coworker Virginia Pierini recently uploaded on ArXiv. We found that according to the EUROSTAT data, several European countries (and Italy in particular) experienced a decline in the healthy life expectancy starting with 2003.

About these results, a disclaimer is in order. The only way to determine HLYE is to ask people how do they feel about their health. Their answer depends on their perception and also on the way the question is posed. So, what these data are measuring might be a decline in the way people perceive their health, rather than their actual health. And there is the further complication that in 2004 some elements changed in the way the measurement was performed. Indeed,  in a comment to an earlier paper by Gennaro et al, Piergentili suggests that the observed change in HLYE is an artifact of the measurement. But we can't rule out that some actual external change had modified people's health, or the perception of their own health. In the paper, we tentatively explored the possibility that this change could be related to the heat wave that hit Europe in 2003 - a phenomenon that, indeed, had a detectable effect on the data on standard life expectancy.

We are the first to say that the data we report are affected by a high uncertainty. But we also thought that these data were worth reporting, if nothing else as a question mark directed at the scientific community for comments. We are facing here a fundamental point: "health" is often considered as equivalent to life expectancy but it should be seen more correctly in terms of healthy life expectancy; also in relation to the changes that we are causing to our environment. Hopefully, this modest effort of ours could be a stimulus to study more this subject.



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)