Monthly Archives: June 2013

What Can We Learn from Civil War Veterans about Chronic Conditions?

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Earlier this month economic historian Robert Fogel died after a short illness at the age of 86.  He was awarded the Nobel Prize in economics in 1993 “for having renewed research in economic history by applying economic theory and quantitative methods in order to explain economic and institutional change.”  Much of his recent work focused on the theory of technophysio evolution.  Well, I had never heard of it either, until reading about it recently while working on the 6th edition edits of my health economics book.  Fogel argues that the advances in human physiology experienced in the past 300 years are not the result of a genetic shift, but the result of environmentally induced changes.  In other words, advances in life expectancy and morbidity are due to improvements in nutrition, public health, medical care, labor-saving technologies, and higher incomes.  His research using data from developed and less developed countries creates an image of the changing nature of human biology.  Having largely defeated the scourge of malnutrition, the western world has seen a doubling of life expectancies and a 50 percent increase in average body size.  Today, even developing countries are beginning to experience similar gains. 

The empirical evidence for Fogel’s theory came from the examination of detailed health and demographic records from 45,000 Civil War veterans who fought in the Union Army.  The most dramatic discovery was the sheer number of chronic health conditions that the typical veteran suffered.  One in four was sent home because of a physical disability, either a hernia, arthritis, TB, or heart problems.  By 1910, two-thirds suffered from arthritis and three-fourths had heart disease.  The comparable numbers for World War II veterans at age 65 was 48 and 39 percent. 

The commonly-held belief had always been that survivors who reached old age in the early 19th century were likely to be relatively healthy.  Fogel shattered that misconception with the fact that the Civil War veterans had an average of 6.2 chronic conditions.  Today, white males who reach age 65 have an average of two chronic conditions. 

The reasons for the significant improvements in health begin early in life.  Infant and adolescent health and along with it survivability have improved substantially.  Undernourishment and infectious diseases, particularly early in life, have been virtually eradicated.  What does this tell us about the future in terms of life expectancy and morbidity?  How will further improvements affect medical care, public health, and retirement?  According to Fogel’s forecasts, an individual born in the 1990s has a 50 percent chance of living to celebrate his or her 100th birthday.  And those advances responsible for the longevity were already in place before ObamaCare.

The economics profession has lost one of the greatest minds we have had the priviledge of knowing.  May he rest in peace. 

 

The opinions expressed in this blog post are mine alone, and do not reflect the opinions of Baylor University.   Baylor is not responsible for the accuracy of any of the information provided in this post.

John Snow and the Beginning of Epidemiology

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Those of us, who toil in obscurity, should take heart.  Good ideas are eventually acknowledged.  I’m working on the changes for the sixth edition of my book Health Economics and Policy and am discovering interesting facts almost daily. 

Public health as a modern-day science can trace its roots back to 19th century England and the pioneering work of young British surgeon, John Snow.  Responsible for advances in anesthetic surgery, Snow is best known for his work in epidemiology during London’s worst outbreaks of cholera between 1848 and 1854. 

The first cholera outbreak in Britain in the modern era occurred in 1831, killing over 23,000 inhabitants.  The government response was minimal, but the aftermath did see an increase public awareness on improving sanitary conditions of the poor and working class.  A white paper was ultimately published in 1842 providing momentum for the passage of the first public health bill in 1848, known unofficially as the Cholera Bill. 

A second cholera outbreak occurred in 1848, followed by another one year later, resulted in 250,000 cases and 53,000 deaths.  During these two outbreaks Snow observed particularly high death rates in the Soho area of London.  The commonly-held scientific belief of the day assumed that cholera was an airborne disease.  But Snow did not accept any of the many miasma, or bad air, theories of transmission.  He argued that because the symptoms were intestinal, it was likely that cholera was a waterborne disease and entered the body through the mouth. 

At the time of the second and third epidemics, there were two water companies serving the Soho district, Southwark and Vauxhall Waterworks and Lambeth Water Company. Both had their water intake source in the tidal basins of the Thames River, downstream from the major population areas.  Using basic spatial analysis to prove his hypothesis, Snow mapped the cholera deaths and identified patterns associated with the water sources available in the neighborhoods. 

In 1854 another cholera outbreak occurred, providing Snow with another opportunity to advance his theory.  This time, however, he was provided with a perfect natural experiment to test his hypothesis.  In 1852 Lambeth moved its water source upstream in an area of the Thames that was not affected by the tidal waters and was thus much less polluted.  Moving house to house, he spent several months mapping the occurrence of the disease and noted the difference in the death rates between the customers of the two water companies.  Lambeth customers had a death rate of 180 per 100,000 customers while the death rate for Southwark and Vauxhall customers was 916 per 100,000, over five times as high.  

Snow was able to convince the local water authorities to take the handle off the water pump on Broad Street (now Broadwick Street) that was the source of contaminated water for many of the local residents, and cholera cases diminished immediately.  He documented his research in a book entitled On the Mode of Transmission of Cholera in 1855.  But the cholera problem did not end there.  Unfortunately most of the scientific community continued to hold to the miasma theory of cholera transmission for several decades.  It was not until Koch and Pasteur developed the germ theory of disease long after Snow’s death that his theory of transmission was substantiated.