[extropy-chat] Are vaccinations useless?

[Hal Finney]

One of the other sources I found at the library was a health economics
textbook that Robin recommended on his web page for his students: The
Economics of Health and Health Care, by Folland, Goodman, and Stano.
This has a nice overview of the areas of consensus and controversy
regarding the causes of the dramatic decline in mortality over the past
250 years.

I have taken the liberty of typing in a couple of pages of the text,
starting at page 100.  I kept the main discussion intact, and then
included a few relevant paragraphs from the next two sections of the
textbook.  I felt that the overall discussion was remarkably gentle;
it almost reminded me of breaking the news to a child about the state
of affairs with regard to Santa Claus.  Keep in mind that this is a
beginning level textbook and that this is what is filling the minds of
budding health care economists.

It is pretty long, so if you are impatient I recommend skipping down to
"WHAT CAUSED THE MORTALITY RATE DECLINES?" and reading three paragraphs
there, then skipping to the final four paragraphs which summarize the
current state of knowledge and its implications.

Again, typos are mine.

Hal

> On the Historical Role of Medicine and Health Care
>
> Among many medical historians, it is agreed that practitioner-provided
> medical interventions played only a small, perhaps negligible, role in
> the historical decline in population mortality rates in countries where
> data are available. Effective medicine is a fairly recent phenomenon,
> and the delivery of effective medical interventions on a scale sufficient
> to affect population health indicators most likely appeared only well
> into the twentieth century.  Though the magnitudes of other causes
> of mortality declines are still disputed, it is clear that a larger role,
> perhaps the most significant one, might be attributed to public health
> measures and the spread of knowledge of the sources of disease.  However,
> at least one provocative scholar in this field attributes the lion's
> share of the credit to improvements in environment, particularly to the
> greatly increased supply of foodstuffs that became available due to the
> agricultural and industrial revolutions.
>
> THE RISING POPULATION AND THE ROLE OF MEDICINE
>
> The notion that medicine played a relatively minor historical role is
> certainly not new, and it has been asserted by researchers of various
> ideologies.  This point of view is associated with the work of Thomas
> McKeown (1976) who focused on the dramatic rise in population in England
> and Wales from 1750 to modern day.
>
> The pattern over time of world population growth, including population
> growth in England and Wales, is one that has posed a significant research
> question to many scholars including McKeown.  World population is hard to
> estimate for the distant past, but recent research by the United Nations
> (1996) and others make some things clear: something extraordinary has
> happened during the last 300 years.  At the time of Christ, the population
> probably reached a record of roughly 300 million people.  For a thousand
> years thereafter, until the era of Viking ships, little or no change
> occurred.  By the Age of Enlightenment, starting just before 1700, the
> population may have risen to 600 million.  Then things began to change.
> Within a single century, the world population passed 1 billion people.
> The next 5 billion arrived within a mere 200 years.  What had happened?
>
> Returning to the history of England and Wales, the large rise in their
> populations in the period roughly following 1750 is to a large degree
> a story of the population's health.  Population increase comes from
> three sources: increased birthrates, reduced mortality, or increased
> net in-migration.  Migration was probably not an important source of
> population increase in England and Wales; when accurate birthrate and
> deathrate data became available from 1841, these data alone proved able
> to account for the population change.  Likewise, fertility probably did
> not account for the change because recorded birthrates declined during
> the period since data became available.  Declines in birthrates are a
> common finding in countries undergoing industrialization or modernization.
> In contrast, recorded mortality rates did decline substantially.
>
> To assess the role of medicine, McKeown began by investigating which
> diseases contributed to the decline in death rates.  Mortality data
> are often limited prior to the mid-1800s, but from available records he
> produced an emerging picture.  Table 5.1 shows death rates by disease
> category for three different time periods.  The table shows that airborne
> infectious diseases account for the largest single portion of mortality
> reduction, and waterborne infectious diseases also make up a substantial
> portion of known causes.  Regarding the airborne diseases, other data
> suggest that the main airborne diseases showing a decline in mortality
> include tuberculosis, bronchitis, pneumonia, and influenza.
>
> WHAT CAUSED THE MORTALITY RATE DECLINES?
>
> Many presume that the declines in mortality rates were due to improvements
> in medical science provided to the public through medical practice.
> Nevertheless, counter-arguments to this proposition bring this presumption
> into question.  In most cases, an effective specific medical intervention
> was not available until late in the period, well after the greater part
> of the mortality decline had occurred.
>
> For example, the argument can be illustrated for the cases of respiratory
> tuberculosis and a group of three upper respiratory diseases - bronchitis,
> pneumonia, and influenza.  Mortality rates for these diseases fell to
> relatively low levels prior to the availability of effective medical
> interventions, whose availability occurred respectively after 1930, and
> for some cases well into the 1950s and 1960s.  The picture is shared
> by waterborne diseases.  About 95 percent of the mortality declines
> in cholera, diarrhea, and dysentery occurred prior to the 1930s when
> intravenous therapies became available.  Likewise, typhoid and typhus
> mortality already had fallen to low levels by the beginning of the
> twentieth century.
>
> The pattern McKeown found for England and Wales also can be illustrated
> for the United States.  McKinlay and McKinlay (1977) provided data for
> the United States from 1900 to 1973.  Figure 5.2 shows these patterns for
> several infectious diseases.  In most cases, as shown, the availability
> of the effective medical intervention occurs well after the majority of
> the mortality decline.
>
> One of the most important changes in mortality in the twentieth century
> was the decline in infant mortality.  Does this type of mortality follow
> the same pattern?  A highly readable account of the modern historical
> pattern of infant mortality is offered in Victor Fuchs' Who Shall
> Live? (1974).  Fuchs noted that infant mortality rates in New York
> City improved markedly from 1900 to 1930 and that this decline was due
> significantly to declines in deaths from "pneumonia-diarrhea" complex.
> Fuchs concluded as follows:
>
>   It is important to realize that medical care played almost no role in
>   this decline.  While we do not know the precise causes, it is believed
>   that rising living standards, the spread of literacy and education,
>   and a substantial fall in the birth rate all played a part... (p.32)
>
> In the 1930s, antimicrobial drugs were introduced.  During the period 1935
> to 1956, the fall in infant death rates accelerated.  Fuchs proposed that
> during this period "both medical advances and rising living standards
> contributed to the reduction in infant deaths" (p. 32).  Declines in
> infant deaths flattened somewhat beginning about 1950 but resumed a
> stronger decline about 1965.
>
> Returning to McKeown's work, if specific effective curative medicines
> were not largely responsible for mortality declines, is it nevertheless
> possible that other tools in the physician's black bag were effective?
> The problem is that there probably were few effective tools in the
> physician's metaphorical black bag until well into the twentieth century.
>
> ON THE ROLE OF PUBLIC HEALTH AND NUTRITION
>
> If medicine cannot be credited with the large declines in population
> mortality rates after 1750, what then can be credited?  Other alternative
> candidate causes seem together sufficient to explain the decline:
> reduction in exposure to infection and improvement in the human host's
> ability to resist infection.  Of these two, reduction in exposure was the
> primary method through which public health measures could be effective.
> The role of public health measures is of interest in itself.
>
> The magnitudes of the effects of these alternative causes, including the
> role of public health, are open to dispute - a dispute whose settlement
> lies largely outside of an account of health economics....
>
> WHAT LESSONS ARE LEARNED FROM THE MEDICAL HISTORIAN?
>
> The study of historical declines in mortality rates is thus one of
> controversy over the relative importance of public health measures
> versus nutrition and other environmental factors.  The consensus is
> fairly clear over the minor role of medical practice....
>
> If the inferences from history are sometimes overdrawn or even
> invalid, what, then, have we learned from history that we can apply to
> modern policy?  Perhaps the best result of this overview is a healthy
> skepticism toward the effectiveness of any given medical practice, and
> more importantly, to its significance and benefits to the population.
> It is in this spirit that the U.S. government has increasingly come
> to fund outcomes studies.  Outcomes studies are intended to address the
> effectiveness and appropriateness of specific medical practices on patient
> outcomes.  The studies attempt to reduce the prevalent uncertainties in
> medical practice, and they offer important inquiries into the wisdom of
> using the marginal billion dollars on health care delivery, particularly
> in terms of costs and benefits to the population as a whole.