IJE Advance Access originally published online on October 1, 2004
International Journal of Epidemiology 2005 34(3):526-529; doi:10.1093/ije/dyh223
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Commentary |
Commentary: The pitfalls of policy history. Writing the past to change the present
Cambridge Groups for the History of Population and Social Structure, Cambridge University, CB2 3EN, UK. E-mail: srjdavid{at}aol.com
Dr Thomas McKeown was probably the most influential and most controversial health historian of his generation, at least in the English-speaking world.
His fame was the result of a radical simplification of health history that can be summarized as follows. For most of human history mortality was high and life expectancy low (between 20 and 30 years at birth) because most people were too poor, and therefore too poorly nourished, to resist the relentless onslaughts of disease, particularly infectious disease. In 18th century Western Europe, agricultural development increased the food supply and let ordinary people buy more and better food. Better nutrition increased their resistance to infectious disease, and reduced death rates, all without the assistance of medical care. It took another century (i.e. 1870) before public health and the decline of fertility made a complementary but still minor contribution to the continuing, nutrition-driven decline of mortality. Thus, if the goal of contemporary health policy is to further reduce mortality, society should invest its resources in the reduction of malnutrition, and more broadly, the eradication of poverty, not more and more sophisticated forms of medical care.
As a rule short summaries automatically oversimplify complex interpretations. But in McKeown's case it was the bold simplicity of his arguments that made them so accessible to experts in different fields, and, as a consequence, so controversial.
For good or ill his interpretation of history profoundly affected research in medical history, mortality history, and economic history, as well as contemporary health policy debates. How a doctor who had no historical training could achieve such influence (most historians do not affect the course of research in one field, let alone three) is exemplified by his 1971 article: ‘Medical Issues in Historical Demography’, which first appeared in Clarke's Modern Methods in the History of Medicine.1
In this article McKeown's considerable rhetorical skills are on display.2 While most professional historians revel in complexity and emphasize differences between earlier and later periods, McKeown minimized them. While most historians are cautious about generalizing, he was not. By stressing historical continuity he made it easy to assume that the past can teach useful lessons to present policy makers.
McKeown belonged to a generation of physicians still influenced by the depression of the l930s and the war which followed it. In the l930s doctors like John Pemberton had argued that in England a large ‘section of the community’ was still too poor to buy enough food to maintain health and activity'.3 During World War II mandatory rationing ensured that everybody got enough to eat. But post-war Britons got free medical care, instead of government supported food programmes. It was in this context, where some medical reformers were still worried about the return of malnutrition, that McKeown turned to history to prove that nutrition had always mattered more to health and longevity than medical care.
In this particular article McKeown provides his arguments about medical history with a demographic foundation, a strategy he had been pursuing for more than a decade.4 He describes the modern rise of population (a future book title) as:
a unique event whose interpretation is not only of the greatest historical interest, one that is also essential to an understanding of some of the most formidable contemporary problems.1
In 1971 the choice of historical demography as an entry point to health policy issues was timely. Created as a new field of research in the l950s it was still being touted as a ‘flagship discipline of the social sciences... a symbol of the new history’.5 By capitalizing on its prestige McKeown could give his claims about medical history a quantitative foundation that they would otherwise lack.
In his second and third paragraphs McKeown starts to explain why it is so important to understand the origins of the modern rise in population that began in late 18th century England (p. 57). But right away he identifies a barrier to doing so—‘data for the eighteenth century are not available’1—and are unlikely to become available. Because of this supposed empirical impasse the only way out of an historical dead end (which McKeown himself had assumed into existence) was through more sophisticated reasoning—not more empirical research.
McKeown subsequently argued that since good demographic data finally became available for England after 1838 (i.e. after the beginning of civil registration) mid-Victorian statistics can be extrapolated back into the earlier period. He stated that 19th century data show that ‘specific measures of preventing or treating disease in the individual made no significant contribution to the reduction of the death rate during the nineteenth century’1 leaving the reader to conclude that the same was true in the earlier period.
This reasoning is problematic in several respects. For one it neglects marked differences between disease environments in the two centuries.
By 1838 England was rapidly industrializing and urbanizing. Its disease environment was dominated by a slew of density-sensitive, epidemic, infectious diseases, mostly air borne or water borne. These diseases were more amenable to public health measures than (then) private medical care. In contrast 18th century England was still predominantly rural and agrarian. Although smallpox was an infectious, epidemic disease, there were other prevalent diseases that were treatable by dietary advice or newly available drugs. Land scurvy was still a problem, but doctors could advise their patients to eat citrus fruits without exposing them to the risk of dysentery, which was greatly feared. Malaria was also prevalent in certain areas of England, but it could be controlled or cured with Peruvian bark now known to contain quinine.6
‘Consumption’ was a leading cause of death in both centuries, but in the 18th century dying from ‘consumption’ meant that pronounced wasting occurred prior to an individual's death, despite the availability of food. Eighteenth century doctors were already aware that gradual wasting away was a symptom that could involve a number of more specific diseases like diabetes and certain cancers. Thus medical reformers had begun urging lay people who assigned causes of death in individual cases to substitute ‘phthisis’ for ‘consumption’ when a wasting death also involved violent coughing. But change was slow. Even in the 1850s consumption deaths were still being reported, especially in rural areas. But once civil registration began, when family members informed local registrars that a relative had died of consumption, such deaths were reported in national vital statistics as ‘phthisis’ deaths.
McKeown assigns great importance to the statistical fact that deaths attributed to ‘tuberculosis’ declined by half from 1838 to 1900.1 He concludes (citing McKeown and Record, 1962)7 that the decline of tuberculosis was clearly caused by a rising standard of living, most specifically an improved diet.1
But ‘tuberculosis’ was not a disease diagnosed or reported as a cause of death much before the late 19th century. Consequently, all that we can be certain of is that nomenclature changed during the 19th century, and it changed in such a way as to ensure a downward trend, given that one, very large disease category (‘consumption’) was gradually reduced to several smaller ones, including ‘phthisis’. As physicians themselves assumed responsibility for assigning causes of death (which they did increasingly from the mid-19th century) medical reformers began urging those who reported ‘phthisis’ deaths to distinguish carefully between true ‘phthisis’ and ‘bronchitis’. Subsequently for more than a decade as phthisis deaths declined, bronchitis deaths rose proportionately.
By 1900 ‘tuberculosis’ had replaced ‘phthisis’, but greater diagnostic precision from 1838 to 1900 was bound to cause a decline of ‘tuberculosis’, when ‘tuberculosis’ is misleadingly substituted for ‘consumption’ and ‘phthisis’ during this period.
To be sure, McKeown raised the diagnostic problem; but he did so only to dismiss it without due consideration. Nevertheless, the decline of ‘tuberculosis’ cannot be accepted as a real trend much before l890. Nor can it be confidently attributed to improved nutrition, given the post germ theory awareness of the need to segregate active cases from the rest of the population, and the rise of sanitoria.
The history of smallpox was particularly problematic to McKeown's nutrition-centred theory of mortality decline. Initially he acknowledged that it was the only infection on which ‘medical measures’ had had an ‘applicable effect’ (p. 66). This is quite an admission, since smallpox had been a leading cause of death in the 18th century. Contemporaries thought it was responsible for 10–15% of all deaths. All McKeown noted is that by 1838 it was a minor cause of death, accounting for ‘only about a twentieth of the total reduction of mortality between 1838 and 1900’. Given his earlier assumption that the 19th century could be read back into the 18th century, the implication was that smallpox was not that important in the earlier century.
But conventional medical history had long assumed that the conversion of smallpox from a major to a minor cause of death between circa 1780 and l838 was due to 18th century inoculation campaigns followed by Jennerian vaccination campaigns in the early 19th century. First McKeown dismissed the importance of inoculation by arguing that even in the 18th century the successful control of one disease could hardly account for the entire decline in 18th century mortality. Subsequently, he denigrated the value of inoculation as a medical measure, thereby implying that it could not possibly have been effective—period. The reader was left to suppose that in reality medicine could not claim credit for the control of even one killer disease.
As a demographic historian I find the sweeping claims McKeown made about future research most startling. Having asserted at the beginning of his article that further research on the 18th century would not turn up anything new in the way of demographic data (a very unlikely eventuality given the newness of historical demography) he acknowledged at the end of the article that, even as he wrote, demographic research on elite mortality was continuing.
Given McKeown's insistence on the supreme importance of nutrition, elite mortality history was particularly problematic. If nutrition alone drove mortality history, it should have been the case that Europe's already well-fed elites ought to have had a mortality advantage over the mass of ordinary and presumably malnourished, people, even before the 18th century decline of mortality began. But geneological data for wealthy families indicated that the average aristocrat did not live any longer than the average peasant, whose births and deaths were recorded in parish registers as baptisms and burials. When McKeown alluded to the problem of mortality equality between privileged and poor, he suggested that aristocrats must have been more prone to violent death than ordinary people. But the published research already available had demonstrated that a superfluity of violent deaths was not the explanation.8
Since McKeown raised so many issues in one short article, it is not fair to expect him to have given each one the detailed attention it deserved. But between 1976 to 1988 McKeown elaborated on his earlier claims in several major books, including the Modern Rise of Population (1976) and The Origins of Human Disease (1988). In a book entitled The Role of Medicine (1979) he argued very explicitly that investing resources in surgery and drugs was a waste of time and money. In every book his critics were mentioned and dismissed as obviously wrong. Although he reviewed more and more empirical evidence, he was so selective that no truly troublesome facts were ever admitted for the reader's explicit consideration.
The debates over how and in what ways McKeown misinterpreted mortality, medical, or economic history have continued. In the 1970s and l980s, when his increasing popularity began to attract the attention of professional demographers and demographic historians, they rejected his nutrition-centred theory of mortality decline on the grounds that it did not fit with continuing research on pre-industrial populations.9
Threatened with dismissal by professional historical demographers, McKeown's ideas were rescued by a prominent economic historian. Professor Robert Fogel adopted McKeown's arguments as the intellectual foundation for his own project on mortality history, the largest ever funded.10 This was a logical move in that the implications of McKeown's arguments were that economic historians were best qualified to explain the modern decline of mortality, since it was little more than a side-effect of declining prices and/or rising incomes on the availability of food.
Some modern development economists also supported McKeown because they were committed to undermining the value of government funded public health reforms as part of their drive to enshrine free markets as the all purpose solution to economic development. Within the medical community, McKeown's ideas received support from those physicians (particularly in America) who opposed the necessity of providing free (i.e. socialized) medical care.11 After all, if medical care did not matter to health and longevity, then government had no obligation to provide it to those who could not afford it.
Although many demographers and economists have critiqued and rejected McKeown's conclusions about mortality history, they remain popular, and must still be described as ‘influential’ in health policy research.12
Despite his shortcomings as a medical/mortality historian, McKeown's humanitarian concerns about the damaging effects of poverty on health (with or without calorie insufficiency) remain relevant to the present health policy.
Today, even in the richest countries, it is generally true that the poorest people live shorter and less healthy lives than the privileged. Free medical care cannot solve the problem of mortality inequality without considerable backup from economic reforms, the aim of which is to reduce the harmful effects of being born and raised under biologically, economically, and sociologically stressful circumstances.
But does medical or mortality history need to be distorted to make a case for social justice in the present? Must the genuine achievements of the great doctors and public health reformers of centuries past be dismissed or devalued to achieve health equality in the future?
Because I firmly believe that the answer to these questions is no, examining Thomas McKeown as a health historian continues to seem like a constructive activity. In the long run bad history does not make for good policy, but then in the long run we are all dead. In the meanwhile the relationship between medicine and mortality remains very much an open question, past and present.
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References |
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 Top References |
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1 McKeown T, Medical issues in historical demography. In: Clarke E (ed.). Modern Methods in the History of Medicine. London: Athlone Press, 1971, pp. 57–74. (Reprinted Int J Epidemiol 2005; 34:515–20.)
2 Johansson SR. Food for thought: rhetorical and reality in modern mortality history. Historical Methods 1994; 27:101–25.
3 Pemberton J. Malnutrition in England. University College Hospital Magazine 1934;Jul–Aug:153–59. (Reprinted Int J Epidemiol 2003; 32:493–95.)
4 McKeown T, Brown R. Medical evidence related to English population changes in the eighteenth century. Popul Stud 1955; 9:119–41.[CrossRef]
5 Rosental P. The novelty of an old genre: Louis Henry and the founding of historical demography. Population (English Edition) 2003; 58:97–130.
6 Johansson SR. ‘Death and the Doctors: Medicine and elite mortality in Britain from 1500 to 1800’. Cambridge Group for the History of Population and Social Structure. Working Paper Series, No. 7, 1–63.
7 McKeown T, Record R. Reasons for the decline of mortality in England and Wales during the nineteenth century. Popul Stud 1962; 16:94–122.[CrossRef]
8 Hollingworth T. A demographic study of British ducal families. Reprinted: Glass D, Eversley D. Population in History. Chicago: Aldine Press, 1965, pp. 354–78.
9 Bengtsson T, Fridlizius G (eds). Pre-Industrial Population Change. The Mortality Decline and Short-term Population Movements. Stockholm: Alquist and Wiksell, 1984.
10 Fogel R. Nutrition and the decline in mortality since 1700: some preliminary findings. In: Engerman S, Gallman R (eds). Long Term Factors in American Economic Growth. Chicago: University of Chicago Press, 1986.
11 Hart JT. McKeown's ‘The Role of Medicine: Advancing Backwards’. Health and Society. Milbank Memorial Fund 1977, pp. 383–88.
12 Davey Smith G. Introduction: lifecourse approaches to health inequalities. In: Davey Smith G (ed.). Health Inequalities. Lifecourse Approaches. Abingdon, Oxford: The Policy Press. 2003, p. xxi.
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