Knowing how long we can expect to live is a difficult enough issue (and yet we are expected to have a go at this in order to secure a suitable pension pot for our old age), but the way news about our life expectancy is interpreted and conveyed can add to these difficulties.
Let me give you an example.
Under the headline Alarm over sudden drop in female life expectancy, in April 2015, it was reported on the Daily Telegraph website that life expectancy for women had declined on a scale not seen for decades. This was based on a Public Health England report entitled “Recent trends in life expectancy at older ages”. Already here, we have an unintended but all the same somewhat misleading statement. The headline could be interpreted as meaning life expectancy at birth, but the cited report talks of life expectancy at older ages (65 years and over). However, put that aside for a moment. More importantly, single year data such as these can indicate – as is the case here – a decline in life expectancies. The data from the report indicated that the average woman aged 75 years could in 2012 expect to live 13.1 years; five weeks less than in 2011, and for a woman aged 85 years, average life expectancy in 2012 was 6.8 years, two and a half months less than in 2011. The data were accompanied by quotes about the canary in the coal mine linking these declines to the rapid decline of state-funded social care. Health officials themselves were more measured, calling for more data from subsequent years to determine whether or not life expectancy was entering a worrying decline.
So let’s fast forward less than 12 months to February 2016. On February 12th, the BBC News website proclaimed that the over 65s in England were living longer than ever before. Confused? Perhaps. Indeed, this is yet another report from Public Health England, which this time states that life expectancy among older age groups in England rose to its highest level in 2014.
Some of any experienced confusion is of course driven by the contradictory headlines we are confronted with – life expectancy going up, coming down, no going up again…
As is often the case, however, the devil is in the detail. As I mentioned above, single year data can indicate a decline, which in fact is no more than a hiccup amid a long-term trend of increase. Because of the way in which life expectancies are calculated by demographers, unusual conditions can lead to an unusual number of deaths, which is then reflected in the life expectancy calculated on the basis of deaths in that unusual year. We need only to think of the slaughter of young men in World War I or the Spanish flu epidemic of 1918-1920 both of which caused massive hiccups in a longer term trend of increasing male expectancies. Thus, demographers are wary of such single year episodes and prefer (as did the health officials in 2015) more data to smooth out these episodes from the trend.
This does not remove an interest in the cause of the episode, however.
Why the sudden drop in 2012? Was it the unhealthy lifestyle of the baby boomers coming home to roost? Well, one would perhaps then expect a decline to last longer than a single year or two. Was cut backs in social care? Again, would we not expect a longer decline?
Whatever it was, people were dying earlier than they should have done, even though the hiccup soon passed.
We have been impressively successful in pushing death to later and later ages while increasing our life expectancies significantly throughout the 20th century and continuing into the 21st century (Leeson 2014 a &b). But we can still experience these unfortunate hiccups, and they should concern policy makers and practitioners, not because they necessarily herald an end to increasing life expectancies but because they are caused by something, and it should perhaps not be happening.
So let’s move just another 2 months to April 2016 to get a sense of what such an episode could be.
Again on the Daily Telegraph website, this time April 7th 2016, we could read that a flu jab blunder had contributed to the largest spike in deaths in a generation according to new data from the Office for National Statistics. The previous winter, there had been more than 16,000 excess deaths and a flu jab blunder had likely made a major contribution to this excess. Public Health England had warned that the main strain of influenza in circulation had mutated unexpectedly, but by that time it had been too late to change the vaccine formula, meaning the jab was largely ineffective.
The large number of unexpected (early) deaths had lowered life expectancy (albeit measured for a single year again) by 2 months for girls and 3 months for boys born that year.
So yes, confusing perhaps, but it makes sense after all.
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Leeson G.W. (2014a) Increasing Longevity and the New Demography of Death, International Journal of Population Research, vol. 2014, Article ID 521523, 7 pages, doi:10.1155/2014/521523.
Leeson G.W. (2014b) Future prospects for longevity, Post Reproductive Health, Vol. 20 (1), pp. 17-21.
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About the Author
Dr. George W. Leeson is Co-Director of the Oxford Institute of Population Ageing, University of Oxford.
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Comments Welcome: We welcome your comments on this or any of the Institute's blog posts. Please feel free to email comments to be posted on your behalf to administrator@ageing.ox.ac.uk or use the Disqus facility linked below.
