Contemporary : Perspectives and Uses'

* Background Rockefeller Foundation to support the establishment Epidemiology is concerned with the study of health, of schools of public health administratively and, unfor- , and health services in groups of people or tunately to a growing degree, intellectually and scien- populations in contrast to the study of other aspects of tifically separate from schools of medicine. The prob- these phenomena in individuals, cells, and molecules. lems are recounted in Professor John Evans' recent Translated literally, epidemiology means "that which report written for the Foundation (2). The disparity is upon the people." Its intellectual siblings are demog- between the population's burden of illness and the raphy, economics, statistics, and sociology, all of health care establishment's priorities for education, re- which had the same origins in the XVIlth century. search, and services has serious consequences for de- Epidemiology is an essential tool for measuring the veloped countries, yet in the developing world, these burden of illness and suffering in the population being consequences are often disastrous. The Foundation's served by the entire health care enterprise, for assessing current hypothesis, held also by other agencies and by the relative costs, risks, and benefits of a wide variety leaders in both developed and developing countries, of interventions designed to improve health, for eval- is that one way to restore to medical science and edu- uating the impact of health services and practice on cation a population-based perspective and eventually the populations' health status, and for developing clues influence the setting of priorities and allocation of re- to the web of causality which influences of sources at institutional and national levels, is to train all types. established young clinical faculty members in epi- The term "epidemiology" was first given wide cur- demiology and to do so in settings where credible cli- rency by the clinicians who founded the London Epi- nicians both care for patients and conduct epidemiolog- demiological Society in 1850 (1). Over the years, how- ical studies. Although the fellows the Foundation sup- ever, epidemiology's clinical origins have been forgot- ports receive a Master of Science degree (or in some ten, and until recently most contemporary clinicians instances a Ph.D.) and are equipped to undertake inde- have had no exposure to the population-based perspec- pendent research on their return home, the main con- tive. Their views are usually grounded in educational cern is the change of attitudes, practices, and priorities. experiences that have been confined largely to tertiary It is too early in the course of the planned evaluation care hospitals and that concentrate on molecular and to judge, but solid evidence now exists in Brazil, the cellular processes. Many, if not most clinicians (mainly People's Republic of China, and Thailand, for exam- those in academic clinical departments) have had little, ple, of substantial changes in attitudes and interests if any, exposure to the concepts, methods, and appli- associated with the return of these promising young cations of epidemiology. It is these academic clini- leaders to their home universities and the establishment cians, especially professors of medicine and surgery, of clinical epidemiology units within the medical who treat politicians and administrators the world over, schools. give advice, and exert a powerful influence based on Epidemiology is the one science that can shift the what they know and experience in university teaching balance in the health care establishment's priorities hospitals. They are unfamiliar with the great bulk of from a predominant preoccupation with individual the population's health problems which exist outside transactions between doctors and their patients to a hospital walls where people live, work, suffer, and broader collective concern on the part of all health die. These distortions of viewpoint and experience have professionals for the care of entire populations. At the resulted in gross imbalances in the organization of very least, epidemiology should help sensitize med- health services, in the training of health manpower, icine to society's health needs and prepare for demands and in the setting of priorities. The net effect is the which will inevitably find expression through the polit- absurd misallocation of resources, intolerable ineq- ical process. In this global arena, the simple definition uities in access to care, and escalating health care costs of epidemiology as "the study of that which is upon which threaten to bankrupt societies. the people" will suffice; more restrictive definitions Much of this isolation from the population-based that refer to "distributions of diseases" or to the perspective is attributable to an earlier decision of the "causes of epidemics" seem outmoded and unhelpful in the broader context in which contemporary health . 'Presented by Dr. Kerr L. White, former Deputy Director for Health problems are now being viewed. Sciences, The Rockefeller Foundation (New York, USA), at the Seminar on Uses and Perspectives of Epidemiology, Buenos Aires, Argentina, 7-10 The epidemiologists' opportunities to contribute November 1983. 13 have been restricted not only by their fragmentation The intellectual tools provided by epidemiology en- into camps concerned with communicable diseases, able all clinicians to examine not only the history of noncommunicable diseases, environmental problems, disorders presented by their patients but also the natural population dynamics, or health services, for example, history of medical care and its outcomes. Both the but also by the arbitrary limitations each camp places hospital-based specialist or consultant and the gen- on the applicability of a rather simple set of ideas and eralist or family physician can undertake epidemiolog- methods to an ever-broadening array of contemporary ical and operational studies, or at least learn to use health problems. The history of epidemiology is replete and interpret the kinds of clinical and management with tales of the strong views expressed by the com- information that is increasingly available to them. In- municable disease epidemiologists with respect to the deed, it can be argued that the medical practice of the legitimate 'application of "their" methods to noncom- future in most industrialized countries will find groups municable diseases and by both these groups with re- of general and specialized doctors with their related spect to the use of epidemiological principles in study- hospitals and facilities taking responsibility for the care ing population trends and evaluating health services. of entire populations, not just of those who present Even now, questions are raised about the appropriate themselves as patients. Their concern and efforts will use of epidemiological methods in the study of such focus on detecting health problems at the earliest pos- contemporary problems as delinquency, social de- sible stage and, when feasible, preventing their occur- viance, emotional deprivation, drug abuse, attempted rence in high-risk groups. To better manage their pa- suicide, and loneliness or even in the study of doctors' tients' health care, general or primary care physicians prescribing patterns or patient's attitudes toward keep- and specialists and consultants will use clinical and epi- ing appointments or complying with treatment regimes. demiological information about them in conjunction There is a definite need for a theoretical framework with data on the populations from which they come. that does not require all noxious agents to be physical, Similarly, health services administrators and the statis- chemical, or biological and that leaves room for such ticians and epidemiologists with whom the clinical complex deleterious influences on health as noise pol- physicians work will be responsible for developing lution, jet fatigue, occupational stress, domestic vio- health information systems to serve multiple purposes. lence, inadequate parenting, and sexual strife. These will include the clinical management of patients Of all the disciplines that constitute the scientific as well as the management of medical practices, health . basis for health care, epidemiology should be the last centers, hospitals, and related resources that serve de- to resort to defensive postures and restrictive practices. fined populations. The health problems and care pro- The fact that laboratory sciences have concentrated on vided will need to be monitored both within medical cellular activities, hospital medicine on the more florid practices and institutions and for local, regional, and manifestations of acute diseases, general practice on national populations. It is one of the tasks of epide- symptomatic treatment of individuals, and traditional miologists to design these health information systems public health on limited services for categorical health so that clinical and administrative decision-making can problems is no justification for epidemiology to limit be based on a reliable flow of useful information. its view of the origins and distribution of health, dis- ability, and distress in populations. Each of these com- Future Challenges ponents has a legitimate role in any contemporary health services system that employs epidemiology di- What follows is a brief consideration of the range rectly or indirectly for at least part of its scientific of tasks contemporary epidemiology could undertake underpinning. It is epidemiology that relates the indi- more aggressively. In all these areas of concentration, vidual to the population and epidemiology that can it has been assumed that, because the studies aspire to help balance personal and public needs, burdens, risks, being scientific in form and content, some attempt has and benefits. One cannot over-emphasize the power been made to measure the phenomena observed. This of the epidemiological viewpoint in redirecting the is as it should be, but it must be remembered that the priorities of most health care establishments. While precision of most measurement instruments varies with there are those who would argue that this is a form of duration of use and is most likely to be improved with market research more compatible with the activities of experience derived from repeated applications. All sci- a commercial enterprise than of a learned profession, ence starts with observing and describing; epidemiol- others contend that this approach redresses the over- ogy is no exception. Many observations can at least emphasis on what has been called "half-way technol- be ranked or scaled, and while not denying the role of e ogy" in medicine. observer error and observer variation, "soft" data

14 about important problems, when objectively collected, it. Effectiveness studies focus as much on those who may be more informative and useful in improving do not use health services or receive efficacious forms health than "hard" data about unimportant problems. of intervention as on those who do. Examples of the former are data on such variables as Efficiency attitudes, disability days, presence of subjective symp- This measures the extent to which a stated level of toms or pain, use of drugs, or measures of perceived effectiveness can be achieved with the lowest expendi- morbidity, in contrast to physiological or anthropomet- ture of personnel, resources, and money. One part of ric data or that derived from ECGs or X-rays. The the equation involves monetary units or equivalents issue is not whether error is present, but rather whether but the other requires measures of disability levels, its nature.and amount in relationship to the observed health status, or disease expressed in units variance of the phenomenon studied can be specified familiar to epidemiologists who themselves are essen- so that important differences can be distinguished with tial participants in designing and conducting confidence. such studies. There are six areas in which epidemiology can be a powerful force in helping society cope with its con- Evaluation temporary health problems; each lends itself to descrip- This generic term can be applied to studies of effi- tive, analytical, or experimental studies. cacy, effectiveness, and efficiency. It requires estab- lishing a "valued" goal, objective, or standard and Etiology assessing the extent to which that goal is achieved as a result of some form of intervention or provision of The traditional search for causal agents or configura- services. This approach to the problems of health and tions of risk factors should be pursued vigorously but health care is especially suited to epidemiologists. should perhaps be approached from an ecological per- Education spective with respect to the nature of disease and its Education offers the challenge of preparing new gen- genesis. Nevertheless, the detection of each new agent erations of epidemiologists and the equally great oppor- or factor found to be necessary, if not sufficient, for tunity (if not obligation) to sensitize and perhaps indoc- the development of any recognizable ailment places trinate clinicians, administrators, and policy makers us closer to ultimate prevention or cure. Epidemiology with the epidemiological viewpoint and perspective. is likely to play an increasingly important role in this These members of the health sector can be made aware regard as new sources of data emerge with the develop- of the need for help from epidemiologists in any ar- ment of contemporary health information systems. rangement of health services that seeks to balance Efficacy equity of access to care, fair shares in the distribution This is concerned with objectively establishing that of resources, and responsible moderation of costs. Both a new form of preventive, diagnostic, curative, or re- clinicians and administrators will have to consider the storative intervention is more useful and beneficial than needs of populations as well as those of individual it is harmful or useless vis-á-vis the purposes for which patients. Inculcation of statistical compassion in ad- it is advocated, or that it is more efficacious than the ministrators and policy makers may be as important type of intervention it is designed to replace or, in fact, as encouraging personal compassion in clinicians. that it is better than doing nothing. This is the arena There is a broad range of uses for the epidemiological of the randomized (RCT). Although there viewpoint and . Epidemiology may be other experimental or observational designs should assume a posture and declare its value as one that provide for the control of selective bias and the of the fundamental sciences that underpins medicine placebo and Hawthorne effects, the predominant means and the other "caring" services. The contemporary is the RCT. It should be noted that the methods for concern in all countries with the provision of health assessing the efficacy of clinical measures are also services requires the epidemiologist's skills. Epide- applicable to the study of administrative practices. miologists themselves should adopt a broader stance and take a more aggressive position. If medicine is Effectiveness being viewed increasingly by society as a social ser- Effectiveness is concerned with measuring the extent vice, then epidemiology should accept the fact that it to which an efficacious form of intervention can be is a social as well as a biological science, and, like all shown to have been made available or applied to all social enterprises, it should serve society. Epidemiol- those in a defined population who could benefit from ogy can be the vehicle for broadening the use of the

15 scientific method in medicine and for putting life, young clinical faculty members and additional financial meaning, and relevance into what could be sterile sta- support will undoubtedly be forthcoming from nation- tistics. Greenwood undoubtedly had this in mind when al, bilateral, and international agencies. The opportu- he remarked that "health statistics record births, nity for epidemiology to serve as society's ombudsman deaths, marriages and divorces; people with the tears of health has never been greater. Latin America can wiped off" (3). Many sources of tears, anguish, dis- show the way. tress, and failure to cope and thrive challenge medicine, the prospects for as do the opportunities for improving References attaining man's full potential. Latin America has an unusual obligation, if not an (1) Lilienfeld, D. E. The greening of epidemiology: Sanitary urgent need, to accept the challenge to broaden the physicians and the London Epidemiological Society (1830-1870). base of epidemiological understanding and the range Bull. Hist. Med. 52:503-528, 1979. of epidemiological applications in the entire health care (2) Evans, J. R. Medición y gestión de los servicios médicos y sanitarios: Necesidades y oportunidades de formación profe- enterprise. Several countries have already shown sub- sional. New York: The Rockefeller Foundation, 1982. stantial initiatives and PAHO is fostering these. The (3) Greenwood, M. Medical statistics from Graunt to Farr. Cam- Rockefeller Foundation offers fellowships for training bridge: Cambridge University Press, 1948.

1------1- 1 Diseases Subject to the International Health Regulations Cholera, yellow fever, and plague cases and deaths reported in the Region of the Americas up to 30 June 1984.

Yellow Fever Country and Cholera Plague administrative subdivision Cases Cases Deaths Cases

BOLIVIA - 2 2 o La Paz - 2 2

BRAZIL - 37 22 8 Amazonas - 9 8 Bahia - - - 2 Ceará - 4 Minas Gerais - - - 2 Pará - 27 13 Rondónia - I I

COLOMBIA - 3 Cesar - 1 1 Cundinamarca - I 1 Santander - I 1

ECUADOR 6 Chimborazo 6

PERU - 17 13 78 Cajamarca - - - 62 Huanuco - t2 8 Junín - 3 3 Madre de Dios -I I San Martín - 1 I Piura - - - 16

UNITED STATES - - - 11 Arizona - - California - - 3 New Mexico -- - 4 Texas - Utah - - - Washington - I . PAN AMERICAN HEALTH ORGANIZATION Pan American Sanitary Bureau, Regional Office of the WORLD HEALTH ORGANIZATION 16 (I 525 Twenty-third Street, N.W. Washington, D.C. 20037, U.S.A.