A panel of five speakers was invited to a symposium in Baltimore in May to celebrate the 30^th anniversary of the Hopkins Summer Program in Epidemiology and Biostatistics. The program has grown over the years from 8 courses in 1983 to 40 courses in 2012 and from 110 students earlier to more than 500 students now. Also, the percentage of students from foreign countries has increased from 10 to 33%, according to Moyses Szklo, Director of the Program.

The theme for the session was the past, present, and future of epidemiology and included presentations by Jiang He, Chair of the Department of Epidemiology at Tulane, focused on the changing global burden of disease, Alfredo Morabia, Columbia University professor, centered on the history of epidemiology, William Moss,  associate professor at Hopkins, on infectious disease epidemiology, Elizabeth Platz, professor at Hopkins, on cancer epidemiology, and Walter Stewart, Director of the Center for Health Research at Geisinger Health System, on the role of research in health care.

Themes

In summarizing the themes which emerged from these presentations, David Celentano, Chair of epidemiology at Hopkins, noted 1) the need for epidemiologists to achieve greater relevance through better translation, 2) the growing role of new technology in conducting research, 3) the role of “big science” as a way of conducting and collaborating on research, and finally 4) the need to revamp epidemiology training in order to better prepare epidemiologists for working in the context of these new realities.

Infectious Disease Epi

Hopkins’William Moss described the changes in infectious disease epidemiology and stated that its demise has been much exaggerated. It is a very exciting time and the future is very bright for infectious disease epidemiology, according to Moss. He gave the example of using mobile phones to decipher social and sexual networks, of remote sensing to look at spatial patterns, and genomic sequencing of pathogens as examples of advances in technology and informatics which are revolutionizing infectious disease epidemiology and allowing better information to be obtained.

Also, novel conceptual frameworks have been put forth such as the idea of a human microbiome. When we come to know that humans harbor ten times more bacterial than human cells, then the idea of “us versus them” no longer seems fitting and the idea of “us” seems more useful.

Another relatively new concept described by Moss to answer difficult questions is that of phylodynamics, a way of exploring more dynamic models of how infectious agents act on and are acted upon. Moss told his audience that training endemic country scientists in the use of these more dynamical approaches was an important task for US programs.

Cancer Epi Good News and Bad

Elizabeth Platz was introduced as a leader in the cancer epidemiology area at Hopkins. She reviewed past successes such as those related to lung and cervical cancer and more recent successes linking aspirin to colon cancer and inactivity and obesity to multiple cancers. Platz also noted some of the problems that the field has experienced, most notably the failure of clinical trials to substantiate the benefits predicted from observational data of beta-carotene in preventing lung cancer. “We did not think adequately,” said Platz, “about such potential influences of dose, timing, and formulation.”

The Rut

She also talked about the “cancer epidemiology rut” in which the nutrient of the day or the SNP (single nucleotide polymorphism) of the day are reported. Often results are not consistent, there is no reconciliation of results, and there is message confusion to the public. She also criticized “Me Too Science” in which investigators revisit the same question in the same way and thus do not always move the field forward, even in incremental ways.

Challenges

For the future, Platz urged that scientists ask important questions and not be guilty of type 3 errors which are getting the right answers to the wrong questions. She urged investigators to go beyond what they have done in the past to not only publish results but to help move findings to implementation. For this type of translational work, she said that epidemiologists would have to learn to collaborate with interventionists and others more involved in implementation. She also called for more studies of patients with cancer to discover modifiable factors that would improve prognosis. For example, what is the role of obesity in cancer outcome?

Among the current hot topics in cancer epidemiology she listed comparative effectiveness research, individualized health, and global cancer. 

Obligations

She closed by reminding the audience that epidemiologists have public service obligations. We know that more than 50% of cancer is preventable and we have an obligation to get that message out there. Don’t perpetuate the “exposure of the day” problem, and don’t obfuscate more important factors, she said, and  suggested that investigators should say no to creating certain press releases when the findings do not warrant it. She closed on a positive note by urging epidemiologists to build on the current momentum which strongly supports cancer prevention.

Global Burden of Disease

Dr He focused his talk on the epidemiological transition which has occurred in low to middle income countries. He showed multiple slides documenting the burden of chronic diseases in the world today attributable to demographic and economic development changes, particularly in China. His conclusions were that chronic diseases, including cardiovascular disease, are the leading causes of death in the world today and that without effective interventions, the increase that has occurred will only continue. He told the audience that control of modifiable risk factors for chronic diseases should be a global health priority.

Idea From History About The Future

Alfredo Morabia’s presentation was focused on finding a single idea from the history of epidemiology that would permit us today to say something about the future of epidemiology. What he concluded from his historical review is that new developments in epidemiologic methods are brought about by challenging health problems associated with changes in society. He illustrated the working of this theme by citing the example of the emergence of the bills of mortality in the 17^th century in association with health challeges from the plague, the comparison of mortality rates from smallpox in the 18^th century between inoculated and naturally infected persons, and of course the work of John Snow in the 19^th century in addressing problems related to cholera. In the 20^th century, problems associated with TB in the early years and with cancer and cardiovascular disease in the second half of the century were also the stimuli for new methodological developments.

Morabia told the audience that if his hypothesis holds, then we can get a glimpse of the future developments in epidemiology by looking at the special challenges in health today. He cited the existence of complex diseases with no single cause and thus no single intervention. These necessitate more multidisciplinary work, lifecourse analytical approaches, and more global monitoring and surveillance of disease. He predicted that epidemiology would shift to being at the center of networks with huge datasets and working with other disciplines. This will require new skills and training for epidemiologists, according to Morabia.

New Model for Research on Health Care

The last presentation by Stewart was perhaps the most different from the others since it did not focus on epidemiology per se but on research more generally and it generated the most interest during the question and answer period. Stewart’s presentation was really anchored in the observation that as countries become wealthier, they spend more on health care and devote a greater share of their gross domestic product (GDP) on healthcare. It is obvious that a country cannot continue indefinitely increasing its share of GDP devoted to health, said Stewart. At some point, the increasing curve must start to bend, and the question which this raises is—what will be the nature of the end game? How will the curve bend?

A major focus of Stewart’s talk was on the role of research in this health care situation. He noted that currently knowledge creation exceeds our ability to use it. He predicted that how we will generate knowledge in the future is changing. He noted that currently the model for knowledge generation is largely housed in academic medical centers which have an incredible wealth of information but this information is divorced from the health care delivery system. He described the R&D model for knowledge generation in business as a model in which translation of the knowledge generated is built into the model. He told the audience that the current delivery system cannot afford a model in which the research is disengaged from the actual business (healthcare) of the system. He noted that business markets behave differently from the health care market in that their share of the GDP shrinks rather than grows over time because of the need to innovate and to provide products better, cheaper, and faster in order to survive. In health care, the share of the GDP has only increased unsustainably.

The model described by Stewart in his work at Geisinger is similar to a drug development model in which ideas move from early trials to more full scale implementation in a structured and sequential fashion. He closed by noting that there is now only a weak translation bridge between academic medical centers and the health care delivery system and that a stronger bridge was needed in order for these centers and the deliverers of care to transform care together.