Google Answers Logo
View Question
 
Q: historic age adjusted life expectancy ( No Answer,   5 Comments )
Question  
Subject: historic age adjusted life expectancy
Category: Miscellaneous
Asked by: peachfish-ga
List Price: $5.00
Posted: 31 Jan 2006 07:27 PST
Expires: 02 Mar 2006 07:27 PST
Question ID: 439616
I'm in the midst of a debate with a friend. He argues that modern
science has not increased life expectancy more than 1-2 years as
historical life expectancy data is artificially low because it
includes infant mortality. I argue that the increase is more than 1-2
years even when you exclude infant mortality. I am having a hard time
finding stats that leave out infant mortality though. Essentially I
need to know the historic life expectancy of individuals who survived
childhood.

Request for Question Clarification by siliconsamurai-ga on 31 Jan 2006 09:34 PST
I am posting this as a clarification instead of an answer because I?m
not certain the answer will be of much help. I suspect the information
you need is to be found someplace in the links below.

The nature of the clarification I seek is whether you feel this is an
acceptable answer?

Let me know, otherwise just say no and another researcher will
probably take a stab at this complex question.

You are right that the data is very difficult to find, I checked lots
of sources and, like you, feel that life expectancy has increased by a
significant amount ? I was always taught that the major cause of
improvement was learning not to put the outhouse close to the well.

Part of the trouble with the statistics is that there simply isn?t
good data for anything prior to about 1920. Average mortality is easy
to find, but the detailed information needed to calculate accurate
life expectancy starting at various ages.

Basically what you want to know is the life expectancy for a given age
? this is usually given for a newborn and this can badly skew charts.
What you need is age-adjusted life expectancy.

For example, before about 1750 infant mortality rates were high in all countries.

In England and France infant mortality dropped to about 20 percent and
remained the same through that century so any increase in life
expectancy for that century would be ?real?.

http://www.fte.org/capitalism/introduction/02.php

There are some interesting numbers at
http://www.napoleon-series.org/research/abstract/population/vital/c_heights1.html

which refers to life expectancy of adult men as being about 45 years
for the U.S. between 1800 and 1820. At the same time it was 38.6 in
the UK, and 36 in France. Although this seems to indicate the numbers
are for adults, I suspect they are based on infant mortality rates and
only the height numbers are for adults.

You can find Human Development Index age for various countries at
http://hdr.undp.org/statistics/

sample
http://hdr.undp.org/statistics/data/indic/indic_1_1_1.html


You can find a report on death rates for various ages in the U.S. at
http://www.cdc.gov/nchs/data/nvsr/nvsr53/nvsr53_05acc.pdf

There are CDC reports on this
http://www.cdc.gov/od/oc/media/pressrel/fs050228.htm

Find life expectancy profiles at
http://www.bbc.co.uk/dna/h2g2/A3784854

Google Search String
Age adjusted life expectancy


Good luck, I predict that your debate could go on for years.

Clarification of Question by peachfish-ga on 31 Jan 2006 10:06 PST
Thanks, I think I did find part of the answer in the last link: "Life
expectancy of both males and females has improved markedly in the past
century. In the 1920s for example, the life expectancy of males and
females was in the late fifties in many developing countries. This
increase is due primarily to a huge reduction in infant mortality
rates in the intervening period. The life expectancy of seniors has
not changed very significantly in that time. A sixty-year-old now can
expect to live into his or her early eighties (an increase from 1920
of just three or four years) and many more people are reaching the age
of sixty than were doing so in 1920."

What this doesn't tell me is how much this changed from, say, 1820. I
think by 1920 there had already been some signifigant medical
advances. I do think a change of 3-4 years from 1920 isn't too bad.

I'm actually really surprised that so many stats include infant
mortality in this measure, it seems like a really easy statistical
mistake. When my friend said that life expectancy stats included
infant mortality I thought he was nuts.

Your answer certainly helped, but I wouldn't mind leaving this open to
anyone else who wants to take a stab at it. It seems like a pretty
basic question and I'm surprised how little information is available.
Answer  
There is no answer at this time.

Comments  
Subject: Re: historic age adjusted life expectancy
From: mikewa-ga on 31 Jan 2006 10:37 PST
 
I don't know if this will help. First: you need to agree on what
constitutes infant mortality: death before age xxx. If you can then
find records for age of death for a substantial population (maybe City
of London records) and compare the distribution above age xxx in 1800
and 2000
Subject: Re: historic age adjusted life expectancy
From: siliconsamurai-ga on 31 Jan 2006 13:28 PST
 
Off hand I get the feeling that this would make a good doctoral thesis.
Subject: Re: historic age adjusted life expectancy
From: peachfish-ga on 31 Jan 2006 14:26 PST
 
It probably would, but I'm not about to head back to school for my
PhD, I just want to win the debate :)
Subject: Re: historic age adjusted life expectancy
From: murunbuchstansinger-ga on 01 Feb 2006 08:13 PST
 
You are most definitely correct.

There you are - tell him you read it on the internet!
Subject: Re: historic age adjusted life expectancy
From: hardtofindbooks-ga on 01 Feb 2006 22:54 PST
 
Hi

here's some figures for you. I have extracted these from several
sources at the US National Center for Health Statistics.

Infant mortality is usually defined as death before the first year of
life is completed. For the examples I have used only the figures for
white males to avoid having to calculate overall averages for the
earlier figures and because it seems to me these figures are likely to
be the least affected by social factors (see discussion below).


Infant mortality is usually defined as death during the first year of life.
So to exclude the effect of infant mortality you need to know the
change in life expectancy in individuals who have reached age 1. I
have also included the life expectancies from age 20 as an arbitary
exclusion of childhood diseases and at age 40 for those entering
mid-life crisis.

Average Remaining Lifetime In Years At Specified Ages, US White Males

Age             1900-02             1949-51              2002

0                 48.23               66.31              75.1

1                 54.61               67.41              74.6

20                42.19               49.52              56.1

40                27.74               31.17              37.4

So, as you can see you are correct when simply excluding infant
mortality and even for greater ages.
However as to causation the relationships may be even more subtle than
you might have thought.
It is going to depend a lot on what you consider 'modern science' and
'medical science'. Much of the improvement in life expectancy is not
due to 'medical science', but rather to other scientific/technological
effects and their interaction with economic and social ones. So it is
possible that more important roles are played by water supply and
sewerage, nutrition, etc than by strictly medical intervention.

e.g. from http://www.allen-unwin.com.au/extracts/pdfs/0335199216.pdf

"As can be seen from Figure 1.1, which depicts the fall in standardized
death rates for the nine common infectious diseases in relation to specific
medical measures for the United States, the decline in mortality from
these major infectious diseases took place before effective medical
interventions became available. McKinlay and McKinlay (1981: 26)
concluded
from their analysis that ?medical measures (both chemotherapeutic and
prophylactic) appear to have contributed little to the overall decline in
mortality in the United States since about 1900 . . .? Similar conclusions
were reached by McKeown (1979) on the basis of an even more extensive
analysis of data from England and Wales."

the relevant references for the above quote are:
McKinlay, J. and McKinlay, SM (1981) Medical measures and the decline
of mortality. In: H. Freeman and S. Levine (eds) Handbook of Medical
Sociology, 4th Edition. Englewood Cliffs, NJ: Prentice Hall.

McKeown, T. (1979) The Role of Medicine. Oxford: Oxford University Press.

Teasing out the contribution of all these factors to the changes in
life expectancy is indeed a subject worthy of many PhDs.

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at answers-support@google.com with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  


Google Home - Answers FAQ - Terms of Service - Privacy Policy