So this is it...we're going to die

[andrewducker]

I was reading the Hacker News discussion of yesterday's link on death and doctors' views on it, and came across this comment which highlighted how small the gains in lifespan over the last hundred years are.

Basically, if you were 65 in 1900 then on average you had 12 more years to live. In 2007 you had 19 more years to live*. If you were 85 then you've gone from 4 more years to 6 more years.

So that's an addition of 7 years and 2 years. Which doesn't seem like very much, particularly as I keep hearing about how much better modern life expectancy is.

Does anyone have any better stats than that? Or any stats for life extension gains in other countries than the US?




*That has to be an estimate, what with it not being 2026 yet.

Comments

[buddleia]

Yeah, but stats like that are complicated by the average life expectancy including infant mortality. I don't know how those ones were reached, mind you.

[redbird]

Much of the gain is in the chance of making it to 65 in the first place: the numbers you quote don't take into account infant mortality, deaths from pregnancy and childbirth, or most deaths in battle.

[cheekbones3]

The mass media have very little apparent understanding that the huge changes in life expectancy are very much due to a hell of a lot more people surviving childhood rather than some miraculous prolonging of life.

A relevant article: http://www.significancemagazine.org/details/webexclusive/1050903/Human-life-expectancy--will-the-young-survive-to-100-years.html

Although it's not the one I was looking for, which was more of a critique of the pitfalls of writing about such matters.

[ciphergoth.livejournal.com]

AFAIK very little research effort has gone into attacking ageing itself. It's fair enough to consider someone like Aubrey de Grey as fringe, but where are the non-fringe researchers? How come it's not worthy of mainstream attention?

[drdoug.livejournal.com]

The motherlode for this information for the UK is the very-excellent Office of National Statistics:
http://www.statistics.gov.uk/hub/population/deaths/life-expectancies/index.html

And the website there helpfully flags up that official figures are (almost) always period life expectancy, rather than cohort life expectancy. Basically, period life expectancy is how long you would expect someone at a particular age now to live if they experienced current mortality rates. So you take a notional person aged (say) 65 now, calculate their chances of dying aged 65 from the mortality stats for 65-year-olds, and then their chances of dying aged 66 from the mortality stats for 66-year-olds, and so on.

Cohort life expectancy is how long you actually expect a person to live. Of necessity this involves some guessing about likely future improvements - which is why period life expectancy is almost always used for comparisons, because it's robust to changes in future expectations: it's a construct based on what has happened, rather than on what we think will happen, and we have much better data about what has actually happened than on what will.

To summarise the UK stats there:
Period life expectancy 2008-2010:
Males at birth: 78.1
Females at birth: 82.1
Males at age 65: 17.8 (= die aged 82.8)
Females at age 65: 20.4 (= die aged 85.4)

Cohort life expectancy 2011:
Males at birth: 90.3
Females at birth: 93.8

The historical motherlode of info is the House of Commons Research Paper 99/111 "A Century of Change: Trends in UK statistics since 1900" http://www.parliament.uk/documents/commons/lib/research/rp99/rp99-111.pdf [PDF]
That only shows (period) life expectancy at birth (on p.8), but you can see it soar over the C20th from just under 50 in 1900 to about 80 now. You can see that most of this is driven by improvements in child mortality in the accompanying graph, which shows infant mortality plunging from about 140 per 1,000 births in 1900 to less than 6 by 1997.

We are not making similarly great strides in improving maximum lifespan. You can also see the top end of this in the stats about the oldest humans (http://en.wikipedia.org/wiki/List_of_the_verified_oldest_people) - there are only 6 living people in the top 100 (and the oldest is at number 15). That wouldn't be the case if we were making dramatic strides here.

You'd want decent odds on a bet that a newborn today won't see their 100th birthday, and staggering odds on a bet that any of us commenting here will see our 120th.

For all this looks gloomy to us who are well over 5 years old, the improvement in infant mortality is bloody brilliant and worth cheering loudly about. One thing that is particularly amazing is that it continues to fall (in the UK, at least) despite it being really pretty low already.

[drdoug.livejournal.com]

Oh, meant to mention the huge disparities and injustices these data throw up. Places like Afghanistan have infant mortalities now that are up where UK rates were in 1900. And even within the UK things vary - (period) life expectancy for a newborn boy in Glasgow City is 71.6, but for a newborn girl in Kensington & Chelsea it's 89.8.

[joexnz.livejournal.com]

Yeah all that stuff about infant mortality and social class!

[undeadbydawn.livejournal.com]

*entirely* off topic:

of all the advances that have increased life expectancy, 80% have been in civil engineering. Most particularly, sanitation and water treatment.

20% are medical.

that's an estimation by - if I remember rightly - a previous head of the Royal College of Physicians. Who was not a civil engineer.

[figures pulled from my unreliable memory]

[octopoid-horror.livejournal.com]

I thought that a more accurate way of casting the issue was to say that when you get to an age that could be considered "old", your quality of life will be better than in the past as you inch towards the inevitable. Well, if you live in a country with a fit-for-purpose healthcare system.

[steer.livejournal.com]

Hold on hold on... You're doing exactly the wrong thing with your stats here.

The life expenctancy (years left to live) at age 85 has increased 50% between 1900 and 2007. The life expectancy (years left to live) at age 65 has increased more than that. Seeing it as an absolute number is not that helpful. So yes... as an absolute number it has not gone up much... but if the absolute number had gone up a lot the effects on mean lifetime and population would be genuinely frightening.

People's expectations about this are not a good guide because in general people are not good at understanding survival functions (including myself and I've written a published paper involving them).