DG: Can you describe the path that brought you to epidemiology?
JP: It was a combination of an interest in medicine and my political interest. As a medical student, I was influenced by friends who were socialists. I joined the Independent Labour Party, and I began to relate medicine to the wider world of politics and legislation. In my second year as a student, the famous Hunger Marches took place from Jarrow to London. A group of us decided to meet the Hunger Marchers outside London, and see what we could give in the way of first aid, and to show our support. I was naturally impressed with the hard conditions that these men were demonstrating against, and in particular the very low rates of unemployment benefits. I wrote an article, “Malnutrition in England,”1 linking nutrition to the level of unemployment benefits. I tried to demonstrate that the unemployed could not purchase the so-called “adequate diet” with the money available from unemployment benefits.
I was influenced by a handful of distinguished doctors who realized that it required political action to remedy such problems as malnutrition, appallingly bad slum housing, and unhealthy conditions at work. One such doctor was James Spence, who became the first professor of child health in the United Kingdom (in Newcastle) in the late 1930s. He carried out a study in Newcastle in which he showed that the children he saw privately were taller, heavier, and had higher hemoglobin concentrations than the poorer children he saw in the hospital outpatient clinic. That impressed me very much. The other man who influenced me especially was Sir John Boyd Orr. He was, in the mid-l930s, carrying out surveys of children and feeding experiments with extra milk and was beginning to show the close relationship between income and nutrition and health. After qualification, when I had the opportunity to join Boyd Orr at the Rowett Research Institute, Aberdeen, to do a 2-year survey of some 5000 children in different centers in the United Kingdom, I jumped at it.
So that’s how I got into this conviction that, apart from treating individual patients, one could throw light upon some of the major illnesses of the time (tuberculosis as well as heart disease and cancer) by studying populations–looking at the whole population and seeing what differences were determined by income, for example.
DG: What’s the biggest difference between epidemiology as it was practiced when you started your career and epidemiology today?
JP: In the late 1930s, epidemiology meant the distribution of infectious disease and its prevention by inoculations and sanitary law. That was the concern of the Medical Officer of Health, and his office did a rather boring job of seeing that the laws of public health were obeyed in regard to water supplies, housing conditions, etc. So we didn’t really connect with epidemiology at all in the 1930s. A key year when this changed, I would say, was 1942, when the first Professor of Social Medicine, John Ryle, was appointed to Oxford University. There had been a small group of doctors who felt, because of their political convictions, that a social approach to medicine was required. The term “social medicine” came into use among our group rather than the word “epidemiology.” It wasn’t, I suppose, until after the end of the War when the discussions for a National Health Service were going on that we began to think in terms of populations.
A big difference between the way I originally practiced epidemiology in the late 1940s and 1950s and the way it’s practiced today is the size of population that we chose to study. When I became the head of the Department of Social Medicine in Belfast, we sought populations of five, six, seven, eight hundred for study. The reason we did that was because the research worker (it was often a social worker) visiting people’s houses, collecting data in a face-to-face interview, couldn’t do more than five or six hundred in the course of a year, and so that became a sort of standard figure.
We didn’t in those days recognize the interference of so many confounding factors. Sometimes we did allow for one factor, for example, tobacco smoking, or obviously major differences by sex and age, but we were very unsophisticated. Richard Doll, on the cancer and cigarette-smoking question, did in fact take a much larger sample of doctors on the Register, but even he did not allow for lots of possible confounding factors that the modern epidemiologist would take notice of. You seem now to have not hundreds but thousands, or even tens of thousands, of subjects for statistical purposes.
The other point was that in our small academic departments, there were only 5 or 6 workers–the Professor, Senior Lecturer, social worker, and perhaps 1 or 2 other assistants who served as computers (“computer” in the old sense of people using machinery to do arithmetic).
DG: Who would you regard as the 2 or 3 most important epidemiologists during your lifetime?
JP: While I’ve had the pleasure of working with international people in the last part of my career, the ones I’ve got to know best and appreciate most have been in the United Kingdom. And with that proviso, I think there would be no doubt that Richard Doll would be in the top group. His work was really meticulous, he used a conscientious approach to data and research, but also of course, working with Bradford Hill, he benefited from the stricter statistical approach and this produced a wonderful combination. I would certainly include Jerry Morris for his work in the Social Medicine Unit of the Medical Research Council, with Richard Titmuss and others. Jerry’s original mind and indefatigable efforts, as well as his book on Uses of Epidemiology,2 made a great contribution. His book was a sort of guide to those of us who were starting courses in social medicine or epidemiology.
DG: Let’s turn to your own research program. What do you think has been your most influential paper, and what’s been your most underappreciated paper?
JP: While I was in Belfast, in Queens University, Department of Social Medicine, the government asked us to look into the question of byssinosis among flax workers. At that time (the 1960s) flax byssinosis was not recognized as a disease qualifying for industrial benefits, although byssinosis in cotton workers was recognized in England and the rest of the United Kingdom. I had an excellent team, including Peter Elwood, who did a great deal of the work, and we examined flax workers in 18 of 19 of the linen factories in Northern Ireland. We demonstrated that byssinosis did occur in the early stages of flax processing. Our findings resulted in a government report called Flax Byssinosis in Northern Ireland3 and subsequently 3 little words were added to the legislation, “and/or flax,” following the reference to the cause of cotton byssinosis. So I could say that our research did have a little bit of an effect in the legislation.
You asked about the work least appreciated. I would think of a paper I did when I worked as a medical registrar in the Royal Hospital of Sheffield. I followed up 200 patients from the medical outpatients a year later, and I found that 20% were dead, another 20% were cured, and 60% still had the disease for which they came up in the first place.4 I don’t think that people had ever really asked how much you do when you see medical outpatients in a big teaching hospital. I think the paper didn’t have much impact because it was distasteful to clinicians to realize that they weren’t doing so very well after all.
DG: What was the method you used to select particular research questions?
JP: Well, sometimes, it was a request from the government, or some influential body. When some institution offers you money to do a particular study, that’s very tempting and then if it’s the government itself, it’s difficult to refuse, especially if you’re the only University, as in the case of Queen’s University then in Northern Ireland. In other respects, in those days the head of a department was very much the determining factor in decisions of that sort. If the head was interested in doing something, well, then the department would organize to do it.
DG: Which of your contributions to the field would you most like to be remembered for?
JP: I always say that I never made an important discovery just by myself, but I think I did bring together a lot of people who did. I was cofounder of the International Epidemiological Association (IEA) with Harold Willard of New York, and I think that association has been successful and has led to collaboration and considerable advances in epidemiology in a lot of different countries. I was just very fortunate being interested in the right thing at the right time. When we founded the IEA, we discovered that although there weren’t many departments of social medicine or many research workers in that field, there were a few, and they were multiplying. The time had come for epidemiologic research to develop. The research we were interested in, and founded the Association for, was the epidemiology of noncommunicable disease. Our little group did bring people together in national or international meetings to give papers and to discuss research and to collaborate.
DG: Outside epidemiology, what have been the major interests in your life?
JP: I’ve always been interested in sketching, painting, going to galleries, looking at pictures and reading. I’ve read much more literature since retiring than before, and I have done a bit of writing. I wrote the biography of Will Pickles,5 the country doctor who made some original epidemiologic observations in general practice. Walking, hill-walking has been a great pleasure. I love the countryside and family. Of course, my late wife and 3 boys were a great experience, a great joy.
DG: In your opinion, what has been epidemiology’s most important contribution to society?
JP: I mustn’t forget the great contributions of the epidemiologists of the infectious disease period—enormous contributions in prevention of disease through inoculations and improved sanitation. In noninfectious disease epidemiology there’s been an enormous surge of light from studying cancer, of course. Cigarette smoking is the outstanding example; also the work of Jerry Morris and the understanding of the causation of heart disease.
DG: What’s your assessment of the current state of health of epidemiology? What are the biggest risks in your view of what our profession faces, and what are the ripest opportunities?
JP: I think it’s in a very healthy state, and the way it’s spread in so many countries now and acknowledged as an important research tool in medicine is indisputable. I think it’s a pity that there’s not so much cooperation with clinicians and clinical problems as there was. I think clinicians in the early days often indicated to us what were important problems to them, with ideas about causation. I think the resources for epidemiologic research are too limited. Obviously a tremendous lot of interest has been put in the molecular side of disease and more recently the genetic side. The target in a sense is getting smaller and smaller in relation to the total target, the total target being the health of the whole population. I am not too impressed with the possibilities of improving the health of the population by research on genetic problems. I may well be quite wrong here.
I think we’re all concerned at the paucity of research workers in epidemiology. It’s a relative term, because there are a lot of people working in epidemiology research, but there are such a tremendous number of problems to be attacked. That’s why I am a bit concerned that such resources as we have are not too much used up on unpromising (or what I regard as unpromising) channels of research. The other major concern is the enormous amount of effort which is put into health service research; it’s not going to discover causes of disease, and that’s what I think our main goal should be.
Some opportunities for epidemiology which have never, as far as I know, been exploited would be an extension of epidemiologic research to other social phenomena—crime, for example.
DG: While you’re speculating, do you have any predictions about what the future must hold for our field?
JP: Well, I just hope that this basic science in medicine—epidemiology—will be more and more accepted in all countries. There are 190 countries in the world and there must be scope for extending this science in some of the poorer countries, and indeed some of the richer countries, too.
DG: What would be the single most important piece of advice you would give to a new epidemiologist starting out on their career?
JP: Well, I think he or she should pick on some disease, accident, or congenital defect that he finds particularly interesting and study that in detail on his own. I think by reading the International Journal of Epidemiology he could probably find out where good research is going on, and then try and get a job under some well-known epidemiologist.
DG: I’ve known you for the last 10 years because of work you carried out leading the fieldwork team in the Boyd Orr cohort between 1937 and 1939. What role did working on that study play in shaping your later career, if any?
JP: It showed me the possibilities and the experience of looking at a population, in this case children, and looking at some of the worst social conditions that could be found in the United Kingdom in 1937. So it was a great experience, and, I’m very delighted and gratified that the records being kept then have proved to be useful for further studies so many years later.
ABOUT THE INTERVIEWER
DAVID GUNNELL is Professor of Epidemiology at the University of Bristol. He is a life-course and psychiatric epidemiologist. The Boyd Orr cohort, based on records in part recorded by Professor Pemberton in the 1930s, formed the basis of David Gunnell’s PhD thesis, in which he examined associations of childhood height, leg length, and weight measures with adult mortality.
1. Pemberton J. Malnutrition in England, UCH Magazine
. 1934;19:153–9 ; republished in Int J Epidemiol
2. Morris JN. Uses of Epidemiology
. Edinburgh: Livingstone; 1957.
3. Pemberton J, Carey GCR, Elwood PC, McAulay IR, Merrett JD. Byssinosis in flax workers in Northern Ireland. A report to the Ministry of Labour and National Insurance, Govt. of Northern Ireland. Belfast: H.M.S.O.; 1965.
4. Pemberton J. A socio-medical study of 200 hospital medical patients. Lancet
5. Pemberton J. Will Pickles of Wensleydale: The Life of a Country Doctor
. London: Geoffrey Bless; 1970.
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