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So('. Sci. Med. Vol. 42, No. 5, pp. 745 750, 1996 Copyright © 1996 Elsevier Science Ltd

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NEW DIRECTIONS FOR HEALTH: TOWARDS A KNOWLEDGE BASE FOR PUBLIC HEALTH ACTION

KATHRYN DEAN t and DAVID HUNTER 2

~Population Health Studies, Ribegade 6 st tv, DK 2100 Copenhagen, Denmark and 2Nuffield Institute for Health, University of Leeds, Leeds LS2 9JT, England

Abstract The need for new types of solutions to respond to community health needs, along with the poor fit between research and the knowledge needed for improving the health of populations, have stimulated a renewal process in the field of public health. Growing out of this movement, an international workshop held at the Nuffield Institute for Health, University of Leeds in 1993 took up issues related to the role and limitations of epidemiology as generally practiced today. Concern for creating a relevant and sound knowledge base for public health action was the impetus guiding this project. Some of the major topics taken up in the deliberations of the workshop are reflected in the selection of papers that follow. They are highlighted and supplemented with an overview of other issues taken up by the conferees in this introduction.

BACKGROUND

Contemporary health systems face major public health challenges that are increasing in both scope and complexity. Many problems remain unsolved, new problems are developing and old public health scourges that were considered past history are returning in new manifestations that present future challenges of unknown dimensions. There is a growing perception of a lack of fit between much of the research conducted on population health issues and the types of research needed for promoting health in communities and securing the change needed in policies and services [1-4]. In spite of documented limitations for providing the range of knowledge needed to solve contemporary public health problems, public health research continues to be constrained by traditions shaped by the domi- nance of the experimental model and clinical practice.

The need for new types of solutions to respond to community health needs, along with the poor fit between research and the knowledge needed for improving the health of populations, contributed to a movement now widely referred to as the +new public health' [2, 5, 6]. Defined as "the application of the biological, social and behavioural sciences to the study of health phenomena in human populations" [6] (p. 70), two defining characteristics pervade the renewal of public health now gaining momentum in most countries [7]. First and foremost, the renewal process is again focusing attention on the forces that protect or damage health in communities, in contrast to the disease focus that characterized the era of biomedical dominance. The second defining char- acteristic of the new public health is the recognition of the need for the collaborative effort of all sectors of society for health protection. The knowledge,

expertise and skills of all health sciences and professions used appropriately and in concert arc necessary for devising and implementing effective responses to the complex public health challenges facing contemporary societies. It also means that research must build on lay knowledge and behaviour to create a basis for effective intersectoral action.

Concern for creating a relevant and sound knowl- edge base for public health action was the impetus for an international workshop held at the Nuffield Institute for Health, University of Leeds in 1993, to discuss the role and limitations of epidemiology as generally practiced today. Some of the major topics taken up in the deliberations of the workshop are reflected in the selection of papers that follow. They will be highlighted and supplemented with an overview of other issues taken up by the conferees in this introduction.

There appears to be an intellectual commitment within the research community to the notion of working collaboratively across disciplines and institutions. It is recognized that health and social policy cannot be based on the research of any one discipline. Complex problems, like health inequali- ties, are not reducible to any one theoretical and methodological predisposition. The understanding and illumination of policy issues demands pluralistic approaches that build appropriately on the qualitat- ive and quantitative methods developed in the social sciences and epidemiology. Despite this intellectual commitment, debates remain alive in some circles on the merits of quantitative versus qualitative research and the place of ethnographic methods of inquiry in relation to the clinical and epidemiological gold standard of the randomized controlled trial [8]. Social science methods have been less valued and respected in the health field [9]. The issue that unites all

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746 Kathryn Dean and David Hunter

researchers of whatever methodological persuasion is their need to be able to communicate meaningfully with both policy and practitioner audiences. While the goal of policy relevant research is a common denominator, there remains great disagreement about the type of knowledge needed and how to obtain new knowledge to meet public health challenges. One major drawback is that public health came to focus narrowly on health services research rather than on health research [10]. This inevitably led to a concen- tration on clinical and biomedical research and on disease instead of research on the environmental, social, political and economic forces influencing health.

The field of epidemiology exerts a great deal of influence on population health research. Contempo- rary epidemiology is characterized by heavy reliance on mortality or a specific disease as the outcome 'health' variable and on experimental design as the optimal form of research investigation. Experimental design and research based on the experimental model do not provide the only or even the best way to conduct research on many health issues. Experimental approaches actually inhibit knowledge development when other types of research are more appropriate. The emphasis on experimental design leads many to try to force survey or intervention research inappropriately into quasi-experimental designs that then violate the standards for both experimental and other types of design.

Powles sees the preoccupation with mechanistic rather than exposure hypotheses and the tendency to concentrate on specific rather than general health outcomes as two major shortcomings of much of the epidemiological literature today. He illustrates these points with research on coronary heart disease:

Cardiovascular epidemiologists have pursued at great length the mechanistic 'lipid hypothesis'; 30 years on, the only dietary factor consistently associated with the risk of coron- ary heart disease in epidemiological studies is (the negative relationship with) alcohol ... Until recently, the major intervention studies have been conceived more in mechanis- tic than in environmental terms testing the effect of specified changes in intermediate variables (plasma choles- terol concentration and blood pressure) ... The continuing controversy over the desirability of lowering cholesterol illustrates the difficulties in interpreting the practical impli- cations of experiments on intermediate variables. It also illustrates the hazards of concentrating on single diseases. There is now a debilitating uncertainty about whether dietary compositions designed to minimize risk of coronary disease by lowering the blood cholesterol concentration increase the risk of other unfavourable outcomes [11].

USING METHODS APPROPRIATELY TO BUILD PUBLIC HEALTH KNOWLEDGE

The papers that follow illustrate the broad range of research needed to provide the knowledge base for effective public health action. The limited types of investigations that receive a disproportionate share of the resources allocated to conduct health research

constrain knowledge development in the field. Studies are needed which draw on the strengths of all methodological options for expanding knowledge about the forces that damage health and about policies and programmes that respond effectively to those forces. All research designs have limitations which are best compensated for by using methods appropriately to supplement each other and by critical analytic reviews of substantive research areas, of research practice and of methodological developments. Rather than the pre-eminence of any particular type of study or analytic methods, it is the appropriate fit of the research design to the knowledge deficit along with the theoretical and methodological soundness of the execution of the study that constitute the common criteria for the public health research needed to inform action.

These issues are taken up by Popay and Williams in the context of developing their central theme that robust explanations of the causes of health and illness must utilize and build on lay knowledge. Systematically processing the experiences of daily life, lay people build up an expertise that while different from that of professionals, must be recognized as parallel expertise. They point out that both professional and lay experts make mistakes, and that the validity and generalizability of both types of knowledge can (and should) be studied empirically. They also discuss the problems arising from the tendency, even obsession in some circles, to contrast qualitative and quantitative research in either/or terms, denigrating the type that is not preferred and lauding the preferred approach. Pointing out that this tendency violates the research principle that the design of a study should always be determined by which approach best suits the research issue to be investigated, they maintain that this mistake would not have been made by the social reformers of the 19th century. We are also reminded that sometimes fitting the research design to the research question is best achieved by linking types of studies. This is the approach chosen in the second paper provided to illustrate the types of new approaches to epidemiol- ogy that are needed to improve the knowledge base for the new public health.

In David Blane's paper, the findings of a pilot project drawing on the perspectives of both natural and social sciences, and integrating qualitative and quantitative methods are presented. Providing evidence from investigations of accurate recall, Blane argues convincingly that research based on retrospec- tive data can compete in quality with that collected in longitudinal studies. Both designs have limitations and advantages. The contributions of this research lie not only in the documentation of the important role of retrospective data and the complimentary nature of multimethod approaches to epidemiological research. This research illustrates the necessity of moving beyond research on single risks to the study of the multicausal forces affecting health for expand-

New directions for health 747

ing knowledge, and is one of the limited number of attempts to find ways that this can be done.

The review of the literature in Blane's paper, along with the findings of the pilot study, supplement nicely the discussion of Popay and Williams on these issues. Virtually all types of data have limitations that need to be recognized. With the possible exceptions of data on life expectancy and the consistent social group differences in mortality within and between countries, most data are characterized by problems of validity and reliability [12-14]. During the first half of this century, experimental studies and mortality data were granted higher status as more rigorous, as 'hard' in contrast to the 'soft' data provided in quantitative surveys and qualitative interviews, and thus believed to provide results that were more scientific and sound. These misconceptions have gradually been challenged by evidence from a broad range of sources that illustrate the weaknesses of so-called hard data and the need for concern about the limitations of data whatever the source [15-17]. Now the process, rep- resented by Blane's work, of proving the hardness of so-called soft data is underway.

A parallel issue revolves around the topic of objec- tive versus subjective evidence. In the era dominated by the experimental paradigm and the biomedical model of disease, data based on laboratory tests, medical records and death certificates were con- sidered objective in contrast to self reported data about health and function, often denigrated as sub- jective and less useful for robust research. As mentioned by Popay and Williams, when subjective data were contrasted with objective data, such as records based on clinical examination, some argued that medical assessments are in some essential way more accurate. A great deal of proof now documents the poor reliability of many of the data sources considered objective [14 17]. At the same time, research evidence indicates that perceived health status predicts mortality more accurately than 'objec- tive' measures [18, 19] and a broad range of evidence is accumulating about the robustness of self reported psychosocial measures [20-22]. We are also reminded that lay knowledge and understanding of ill health have frequently provided early warnings about en- vironmental dangers, warnings ignored or discounted by scientists to the peril of all. Rather than contrast- ing subjective and objective data the relevant point is that most all knowledge is relational rather than universal [23]. Our task is to understand the relation- ships among the forces affecting health and how they are modified by time and context [24].

The research reported by McKinlay et al. adds a new dimension to the traditional stereotypes of what is rigorous and robust by using an experimental design in research that documents subjective dimen- sions of diagnostic decisions made by medical doctors. Here we see the design that was granted 'gold standard' status in biomedical research used to study the objective/subjective component of medical

decisions. Supplementing a broad range of studies using social science methods, it was found with a controlled factorial experimental design that diagno- sis and treatment decisions are affected by influences such as sex, age, and type of practice rather than by diagnostic criteria alone.

The findings from these studies, and from the research the authors review, highlight the need to use the range of research options available for building knowledge in the field of public health. The funda- mental challenge facing public health is to move beyond important, but limited epidemiological approaches, to creating an appropriate and sound knowledge base for public health action [25, 26]. The keys to expanding knowledge are the appropriate fitting of methodological options to research issues, the use of complementary methodologies, and the replication of findings in sound high quality research investigations. Powles reminds us that some of the most pressing research issues are related to ecosystem disruptions that can only be assessed by modelling the complex systems involved and judging how humans are being affected [27]. Modelling complex interactions among multiple causal influences affect- ing health and research to explore the conditions that modify causal processes have generally been neg- lected in research on population health issues [24].

BARRIERS TO INTERDISCIPLINARY RESEARCH

Although interdisciplinary research is heralded as important and considered a distinctive feature of the new public health, the pressures operating on the research community tend in practice to favour a competitive approach over a collaborative one. Both behavioural and structural barriers interfere with the types of collaborative work needed. Like the medical profession, public health researchers tend to pursue their respective missions on an individualistic basis rather than through collaborative effort. The individ- ualism breeds separateness and a tribalism character- ized by territoriality and lack of trust. The relevant range of research skills as well as management skills for negotiating, bargaining and team building remain underdeveloped when individualism and preoccupa- tion with controlling territory dominate a field. The individualistic ethos is held in place by system bar- riers that channel research funding into traditional power networks rather than according to the exper- tise needed for meeting the knowledge deficits, and by the underdeveloped options for interdisciplinary re- search education in the field of public health relative to other fields that build on the knowledge, methods and skills of multiple academic disciplines. These barriers are illustrated in Scally's discussion of difficulties encountered in the U.K. attempts to get members of the medical profession who work in the field of public health to broaden the base of their organization. Scally notes this narrow professional protectionism is unlikely to be successful and is

748 Kathryn Dean and David Hunter

stimulating the creation of multidisciplinary public health organizations in the U.K., a process well developed in the U.S, and now occurring in Europe.

The requirements in academic systems in terms of career development and progression in Universities compound the problem. The flow of resources does not favour the types of interdisciplinary research needed for effective public health action. Publication expectations and research assessment criteria pose additional obstacles to working collaboratively, either within one's own discipline or across disci- plines. In the U.K., for example, the research assess- ment exercise, which is crucial for research funding to universities, and to departments within them, forces academics into units of assessment which make trans- departmental links difficult or impossible to develop.

Traditions within disciplines that are difficult to break down, for example the tendency for qualitative and quantitative researchers to work territorially and denigrate the approach that is not their own, also constitute a barrier to progress. This is compounded in the field of public health, relative to other interdis- ciplinary applied fields, by the lack of options for research education in diverse methods and in fitting research methods to research issues appropriately. This barrier will grow in magnitude since many of the advances in knowledge today occur from the inte- gration of the knowledge and skills of different disci- plines.

Unless the barriers impeding interdisciplinary re- search are addressed, calls for greater collaborative effort will make no impact on the realities of actually conducting research. Moving from tribalism to integrated academic efforts is a prerequisite for build- ing the types of knowledge about health problems and solutions promised by the new public health. Isolated projects that break with tradition can do little to meet the knowledge challenges. It will be necessary to teach networking skills to achieve the open mindedness, humility and ability to manage boundaries that are prerequisites for achieving the collaborative approaches needed. Most importantly, infrastructures that support collaborative effort must be built. Schools of Public Health and their equiva- lents in the health policy field, have a particular responsibility and role to play in developing collabo- rative research and providing reseach education and management training to assure that the requisite knowledge and skills are obtained.

TRANSFERRING KNOWLEDGE INTO PRACTICE

As discussed earlier, the impetus for the renewal occurring in public health is the need for more effective public health action, along with the corre- sponding need for new approaches to epidemiology. The Leeds initiative grew out of an interdisciplinary concern for attaining a better fit between public health problems and the knowledge base for develop- ing effective solutions. Thus the meetings of the

workshop focused on research issues and how to develop a new epidemiology. However, since the underlying concern was the more appropriate action to be derived from improved understanding of the forces that protect health or contribute to its deterio- ration, we should not close without touching on the subject of knowledge transfer.

Getting research into practice has become a major preoccupation of policy-makers anxious to see im- provements in the cost-effectiveness of health care systems. A new industry is rapidly developing in the area of database management and information dis- semination in an attempt to bring the fruits of research to the attention of policy-makers, managers and practitioners. The issue goes beyond the mere dissemination or diffusion of information. Data do not provide knowledge unless appropriately and validly analyzed. Many available data sets have not been analyzed and many of those which have build on the types of misleading research which the new epidemiology seeks to replace [28, 29]. Many of the concerns regarding knowledge development have been taken up in the preceding sections, but there remains an issue related to how policy makers use the findings from research. Compelling evidence is insufficient in itself to secure change in practice. An intention to bridge the gap between research and practice is of no value unless it can be translated into action.

A major aspect of the challenges involved in policy development has to do with the difficulties of address- ing health issues in the context of other social issues. Making research and policy in public health more congruent is a prerequisite, but policy cannot be expected always to flow from research. The criteria will always remain the utility of the research and the potential for utilization of the research findings. The critical features of these criteria include the: relevance of the topic, validity of the study, timeliness of the findings, feasibility of the recommendations and targeted dissemination. Traditionally, public health researchers have not been very interested in designing research that meets the needs of policy-makers. For instance, research related to the aims and objectives of the WHO Health for All policies accepted by the countries of Europe is virtually non-existent. The national health strategy for England, Health of the Nation, has not spawned research aimed at evaluating its impact. Most health services research is directed towards health care, its delivery and the development of guidelines and protocols. Health policy research is underdeveloped, as is research to provide the knowl- edge base for intersectorat action.

To begin to tackle these deficits, new types of alliances between policy-makers, managers and the research community are needed. The interdisciplinary meeting held at the Nuffield Institute for Health was a modest attempt to create such an alliance. The mix of participants and the breath and quality of the discourse illustrated the potential for creating new

New directions for health 749

forms of health research that are relevant, appro- priate and scientifically sound. It is noteworthy that this group of epidemiologists, social scientists, com- munity physicians, and policy analysts were able to reach consensus on a research policy statement that recognized:

- - t h e need to refocus public health research on the root causes of ill health and disease

- - t h e need to understand the forces that keep people well as well as those that make them ill

- - t he value of lay knowledge for understanding health protection and the processes involved in its deterioration

- - t h a t choosing the appropriate methodology for each situation is the key to good research and problem solving

- - t h a t all types of public health research must meet rigorous standards

- - t h e wide range of academic disciplines and health professions that have equally valuable contributions to make to public health research and practice

- - t he need for lay people and professionals to work together to define problems and solutions

- - t h a t research funding should be allocated according to these principles [30].

Schools and Institutes of Public Health have a special responsibility to develop the types and levels of education required to achieve these goals, and to help bring about and sustain linkages between the policy and research communities. Frenk argues that schools need to look beyond their boundaries to the growing complexity of their surroundings and combine academic excellence with attentiveness to policies and decisions affecting the health sector [6]. Since government departments are reluctant to sponsor research that might yield uncomfortable evidence which might lead to questions about current policy, a diversity of funding sources for research along with mechanisms to hold all actors in the health sector accountable are essential.

REFERENCES

1. World Health Organization. The Crisis of Public Health: Reflections for the Debate. Scientific Pub. No. 540, WHO Pan American Health Organization, Washing- ton, D.C., 1992.

2. Bury J. Training and Research in Public Health: the Policy and Plan of Work of WHO~Europe. Centre for Public Health Research, Karlstad, 1994.

3. Population health looking upstream (editorial). Lancet 343, 429, 1994.

4. Gillett G. Beyond the orthodox: heresy in medicine and social science. Soc. Sci. Med. 39, 1125, 1994.

5. Ashton T. and Seymour H. The New Public Health. Open University Press, Milton Keynes, 1988.

6. Frenk J. The new public health. In The Crisis of Public Health: Reflections for the Debate. Scientific Pub. No. 540, WHO Pan American Health Organization, Wash- ington, D.C., 1992.

7. We are reminded by Popay and Williams in the opening statements of their paper below, that the origin of public health in the 19th century was based in work on root causes of ill health in communities. Ground breaking research discoveries of that era uncovered environmen- tal and social conditions that allowed effective responses to major public health problems. What is now widely referred to as the 'new public health" is actually a struggle to reintegrate essential components of under- standing and responding to public health issues that were lost or seriously neglected in the era dominated by the experimental paradigm.

8. Hunter D. and Long A. Health research. In Directory of Social Research Organizations in the U.K. (Edited by Sykes W., Bulmer M. and Schwerzel M.). DSRO, London, 1993.

9. McKinlay J. The promotion of health through planned sociopolitical change: challenges for research and pol- icy. Soc. S~i. Med. 36, 109, 1993.

10. McQueen D. Study of Research and Training in Public Health. Zukunftsungfgabe Gersundheitsforderung, Lunderverland Der Betriebshranhenhusen, Berlin, 1989.

11. Powles J. Letter to working group project on creating a knowledge base for public health action, Nuffield Institute for Health, Leeds, 1994.

12. Uemura K. and Pisa Z. Trends in cardiovascular disease mortality in industrialized countries since 1950. Wld Hlth Statist. Q. 41, 155, 1988.

13. Levi F., Lucchini F. and La Vecchia C. Worldwide patterns of cancer mortality. Eur. J. Cancer Prey. 3, 109, 1994.

14. Percy C., Staneck E. and Gloeckler L. Accuracy of cancer death certificates and its effects on mortality statistics. Am. J. Publ. Hlth 71, 242, 1981.

15. Gotdacre M. Cause-specific mortality: understanding uncertain tips of the disease iceberg. J. Epidemiol. Commun. Hlth 47, 491, 1993.

16. Goldman L., Sayson R., Robbins S., Cohn L., Bettmann M. and Weisberg M. The value of autopsy in three medical eras. N. Engl. J. Med. 308, 1000, 1983.

17. Gotzsche P. Bias in double-blind trials. Dan. Med. Bull. 37, 329, 1990,

18. Kaplan G. and Camacho T. Perceived health and mortality: a nine year follow-up of the human popu- lation laboratory cohort. Am. J. Epidemiol. 117, 292, 1983.

19. Idler E., Kasl S. and Lemke J. Self-evaluated health and mortality among the elderly in New Haven, Con- necticut, and Iowa and Washington Counties, Iowa, 1982-1986. Am. J. Epidemiol. 131, 91, 1990.

20. The growing volume of literature on these subjects is extensive and should be examined in depth by those interested. Some examples: Maddox G. and Douglass E. Self-assessment of health: a longitudinal study of elderly subjects. J. Hlth Soc. Behav. 14, 87, 1973.

21. Jylha M., Leskinen E., Alanen E., Leskinen A. and Heiddinen E. Self-rated health and associated factors among men of different ages. J. Gerontol. 41, 710, 1986.

22. Cohen S. and Syme L. Social Support and Health. Academic Press, New York, 1985.

23. Suppe F. (ed.) The Structure of Scientific Theories. University of Illinois Press, Chicago, 1977. This subject is taken up in several of the contributions to this comprehensive overview of major issues in scientific reasoning. Also see [7].

24. Dean K., Kreiner S. and McQueen D. Researching population health: new directions. In Population Health Researeh: Linking Theory and Methods (Edited by Dean K.), p. 227. Chap. 1, 2 and 5. Sage, London, 1993.

25. WHO 1992, 1995, op cir.

750 Kathryn Dean and David Hunter

25. Dean K. Creating a new knowledge base for the new public health (editorial). J. Epidemiol. Commun. Hlth 48, 217, 1994. Powles, op cir.

27. Powles refers to McMichael A. Global environmental change and human population health: a conceptual and scientific challenge (editorial). Int. J. Epidemiol. 22, 1, 1993.

28. Hulley S., Walsh J. and Newman T. Health policy on blood cholesterol: time to change directions. Circulation 86, 1026, 1992.

29. Dean K. Using theory to guide policy relevant health promotion research. Hlth Promotion Int. 11, 19, 1996.

30. The Leeds Declaration. Nuffield Institute for Health, Leeds, 1993.