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Comparisons between geographies of mortality and deprivation from the 1900s and 2001: spatial analysis of census and mortality statistics

BMJ 2009; 339 (Published 10 September 2009) Cite this as: BMJ 2009;339:b3454

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Le plus ca change le plus c'est le meme chose?

Dear Sir: Yesterday I walked into the pub and ordered a pint of
Guinness, and the bartender told me "That'll be 10 quid." I was
astonished, and replied "How is it 10 quid today when it was only 5 quid
yesterday?" The bartender answered with a roll of his eyes, as if speaking
to child, "Well, you see, my good man, yesterday a shepherd's pie cost 10
quid, and today it costs 20 quid, so you see, the price of the Guinness
hasn't actually changed at all." "Whatever do you mean?" said I, irate at
the blatant dishonesty. "I walked in here yesterday and laid down 15 quid
for a good meal that today will cost me 30. How is that the same?" Again
the bartender looked pained to make the logic plain to someone so immune
to the good sense of arithmetic. "Your relative expense for stout was 0.5
yesterday, and it is 0.5 today, so what are you complaining about? If I
left the price of Guinness the same, then you'd be whining that shepherd's
pie cost twice as much. But instead, I've kept everything equal. It was 2-to-1 yesterday and it's 2-to-1 today." I walked out annoyed, as my salary
was 100 quid a day yesterday and 100 quid a day today, and I was not eager
to spend 30 for what I used to spend 15. And this got me thinking about
the article that I read in the morning from the British Medical Journal.

Surely epidemiologists understand arithmetic as well as the bartender, as
they claim that a standardized mortality ratio (SMR) of 2 in 1900 is the
same as an SMR
of 2 today. Never mind the numbers in the numerator or in the
denominator, it is only the ratio that matters. Of course there hasn't
been any inflation in the unit of currency used in their study: 1 life is
still 1 life, and that is exactly how much each person can spend in the
process of dying. So it seems that the BMJ takes the same position as my
bartender. Nothing at all has changed.

Competing interests:
None declared

Competing interests: No competing interests

11 September 2009
Jay S Kaufman
Associate Professor of Epidemiology
McGill University, Montreal, Montreal, Quebec H3A 1A2 Canada