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.



  1. What happened with Sweden? Interesting how the global economic troubles in 2008 didn't seem to cause a blip.

    -Dave Neiman

  2. Ugo, would it be possible to remove all the little triangles and squares and circles? I find the chart to be illegible, and the all the doodads do not add any useful information to this discussion.

    1. Hmmm... yes, the figure is not so easily readable. But if you click on the link to the ArXiv paper, there are more figures and data

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  4. Here in the UK we are apparently short of Nonagenarians. That is, our Office for National Statistics predicts, each year, using the present demographic curve, what the future curves will look like. And the real future, compared with the predicted one, apparently has a big hole where the over-90s should have been. Particularly the poor over-90s.

  5. The UNDP Human Development Index : http://hdr.undp.org/en/statistics/hdi/ and Bhutan’s "Gross National Happiness" index : http://www.grossnationalhappiness.com/ which is also described here: http://en.wikipedia.org/wiki/Gross_national_happiness face similar measurement and interpretation problems with some of their own subjective (and composite) variables.

    I think this HLYE study is very interesting and also important and potentially useful - both to individuals and to policy makers. Offhand and without knowing more than what is stated in the post, I would tend to believe and concur with the idea that the changes observed may be due to measurement error or may reflect perceptions more than actual underlying “health” realities- however these might be objectively measured if they can be.

    To measure “development” the UNDP had to do quite a bit of dis-aggregation work first and then (I think) construct a composite index assigning different weights to different factors, which is itself a subjective process.

    Often when “things” (?) are getting “better” (?) people tend to be “happy” (?) and when they are getting “worse” (?) (than they were before) they tend to be “unhappy”. (?) And this regardless of how good or bad things were to start with. Not to even mention all of the question marks.

    And then there is also the fact that if one “feels” “healthy and happy”, that probably also tends to make that person more “healthy and happy” even on so called “objective” measures. Maybe chemistry and physics or archeology are easier?



Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014)