8282 WDDTYWDDTY | JUNE 2019| ISSUE 01 | AUG/SEP 2019 FACEBOOK.COM/WDDTYAUNZ
Taking the credit
Modern medicine has had surprisingly little to do with the decline in mortality rates
W
hat has medicine ever done for
us? Well, there’s antibiotics.
And chemotherapy. And
vaccinations. OK, apart from
antibiotics, chemotherapy and vaccinations,
what has medicine ever done for us?
Not so fast. They’ve helped combat
infectious diseases, haven’t they, and, as a
result, there’s been a 74 percent decline in
mortality rates in developed countries since- Pretty impressive, no?
It’s true. One of the greatest, and unsung,
achievements of mankind has been the
defeat of 11 major infectious diseases—
including cholera, scarlet fever, smallpox,
whooping cough and measles—which
accounted for 40 percent of all deaths in the
United States in 1900. In that year, the death
rate stood at around 17 people per 1,000 in
the population.
By the late 1940s, the rate had dropped by
about 40 percent, to roughly 10 people per
1,000, and it continued to slowly decline
through the start of the twenty-first century.
Although it’s begun to creep back up, from
a minimum of 7.9 people per 1,000 in 2009
to a rate of 8.4 per 1,000 in 2016, this still
represents roughly a halving of the death rate
since 1900.
If you’d searched earlier than 1900—which
you can do with data from the UK—you’d see
that the death rate had started to decline from
around the 1850s.
Looking at specific diseases, you’ll see a
similar pattern. The death rate from measles
in the UK in 1860 was more than 1,000
children per million, and it had dropped to
less than 100 per million by 1950, a ten-fold
reduction.But an early version of the measles
vaccine was introduced only in 1963.
Then there’s whooping cough (pertussis).
In 1890, the death rate was around 900 per
million children; by 1930, it was down to
around 200 per million. But the DTP vaccine
was introduced only in 1940.
Bryan Hubbard
THE LAST WORD
REFERENCES
1 Popul Stud (Cambridge), 1975; 29: 391–422
2 Milbank Mem Fund Q Health Soc, 1977; 55: 405–28Scarlet fever was killing around 600
children per million in 1890, which fell to
fewer than 100 per million by 1930. But
penicillin was introduced only in 1942.
So what’s really caused this sharp decline?
It’s a question that has fascinated doctors and
medical historians for years. Leading the way
was English physician Thomas McKeown,
who examined the decline in the death rate in
England and Wales over three centuries.
He notes the decline started during the
eighteenth century, which he attributes to
improvements in the environment, but it
became steeper in the second half of the
nineteenth century, which was wholly
caused by a loosening of the fatal grip of
infectious diseases.This drop in infections
can be explained by three factors: rising
living standards, especially better diet and
nutrition, improvements in personal and
public hygiene, and a “favorable trend” in the
relationship between some micro-organisms
and their human hosts.
But, he emphasized, medicine made an
insignificant contribution to this decline. The
effect of immunization, such as it was, was to
restrict smallpox, and this accounted for just 5
percent of the reduction in the death rate.The fall continued throughout the
twentieth century, driven by improving
nutrition, better public sanitation and “less
certainly” immunization. Nutrition on its
own was responsible for half of the drop
in death rate, McKeown estimated, with
sanitation being responsible for one-sixth,
or 16 percent, and immunization and other
medical therapies combined responsible for
just one-tenth, or 10 percent.^1
Warming to the theme, husband-and-
wife team John and Sonja McKinlay, both
epidemiologists at Boston University,
estimated that 92 percent of the decline in
the mortality rate had happened in the US by
1950, and agreed with McKeown that medical
measures had very little to do with it. In fact,
they were even more conservative, estimating
that medicine—particularly vaccinations and
antibiotics—was responsible for just 1 to 3.5
percent of the decline.^2
And they sound a warning that, to today’s
ears, sounds prescient. “It is not uncommon
today for biotechnological knowledge and
specific medical interventions to be invoked
as the major reason for most of the modern
decline in mortality.”
In other words, medicine and its
paraphernalia have taken undue credit for a
decline that was caused by other factors, and
as a result, it has been rewarded by society with
billions of dollars in gratitude.
Or as medical historian René Dubos put
it in his seminal 1959 book Mirage of Health,
“When the tide is receding from the beach it
is easy to have the illusion that one can empty
the ocean by removing water with a pail.”
The McKinlay Study, as it became known,
was required reading in medical school for
many years until it was quietly removed.
That would have told aspiring doctors that
medicine really hasn’t ever done much for us.Medicine—in particular,
vaccinations and antibiotics—
was responsible for just 1 to 3.5
percent of the decline in the
death rate in the 20th century