Epidemiology: Then and Now.

Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies.

Cultivating Hygiene as a Science: The Welch-Rose Report's Influence at Johns Hopkins and Beyond.

In 1915, William Henry Welch and Wickliffe Rose submitted a report to the Rockefeller Foundation that became the template for public health professional education in the United States and abroad. Based on the Welch-Rose Report's recommendations, the Foundation awarded a grant to Johns Hopkins University in 1916 to establish the first independent graduate school of public health, with Welch serving as the founding dean. The Welch-Rose Report and, by extension, the Johns Hopkins School of Hygiene and Public Health established and transmitted a new model of scientific training that wove the laboratory mindset together with the methods of public health administration and epidemiologic fieldwork. During the School's first quarter-century, faculty and alumni were remarkably active in frontline public health problem-solving, as well as launching public health agencies and schools of all types and sizes. The most lasting contribution of the Welch-Rose Report and the Johns Hopkins School of Hygiene and Public Health, now the Johns Hopkins Bloomberg School of Public Health, has been to "cultivate the science of hygiene" to bring about exponential growth in the evidence base for public health. The schools that have adopted the Johns Hopkins model of public health education worldwide have produced professionals who have worked to achieve wide-ranging reforms dedicated to preserving life, protecting health, and preventing injury across populations and continents.

The Johns Hopkins Bloomberg School of Public Health: A Brief History of a Century of Epidemiologic Discovery.

During its first century, the Johns Hopkins University Bloomberg School of Public Health has been home to several faculty members who have played leading roles in defining and expanding the field and science of epidemiology. They have done so by training leaders in the field, creating new methods and applications, and making relevant discoveries in the worlds of infectious and chronic diseases. These methodologic innovations and discoveries underlie many of today's major health policies and practices.

Leadership of the Department of Epidemiology of the Johns Hopkins Bloomberg School of Public Health in Its First Century.

This commentary reviews the contributions of each of the 7 Chairs of the Department of Epidemiology from the Department's inception in 1919 to the advent of the Centennial Celebration of the Johns Hopkins Bloomberg School of Public Health in 2016. The founding Chair, Wade Hampton Frost (1919-1938), was among the handful of foundational thinkers in the discipline of epidemiology. Kenneth Maxcy (1938-1954) and Philip Sartwell (1954-1970) oversaw the Department through the epidemiologic transition from a preponderance of morbidity and mortality due to infectious diseases to a preponderance of noncommunicable diseases. Abraham Lilienfeld (1970-1975) and Leon Gordis (1975-1993) were perhaps best known for their mastery of teaching, influencing generations of both medical and public health students. Jonathan Samet (1994-2008) oversaw a major curriculum revision and expanded the Department significantly, and David Celentano (2008-) is working to rebalance the practice of epidemiology with the etiological foundations of epidemiology. All Chairs were a product of their times, and their research focus and portfolios influenced the direction of the Department. Future generations of Johns Hopkins students will be influenced directly or indirectly by the heritage of these Chairs' actions and those of their faculty.

The George W. Comstock Center for Public Health Research and Prevention: A Century of Collaboration, Innovation, and Translation.

The Johns Hopkins Bloomberg School of Public Health has been engaged in public health research and practice in Washington County, Maryland, nearly since its inception a century ago. In 2005, the center housing this work was renamed the George W. Comstock Center for Public Health Research and Prevention to honor its pioneering leader. Principles that guided innovation and translation well in the past included: research synergies and opportunities for translation realized through longstanding connection with the community; integration of training with public health research; lifelong learning, mentorship, and teamwork; and efficiency through economies of scale. These principles are useful to consider as we face the challenges of improving the health of the population over the next 100 years.

Statistical Reasoning and Methods in Epidemiology to Promote Individualized Health: In Celebration of the 100th Anniversary of the Johns Hopkins Bloomberg School of Public Health.

Epidemiology is concerned with determining the distribution and causes of disease. Throughout its history, epidemiology has drawn upon statistical ideas and methods to achieve its aims. Because of the exponential growth in our capacity to measure and analyze data on the underlying processes that define each person's state of health, there is an emerging opportunity for population-based epidemiologic studies to influence health decisions made by individuals in ways that take into account the individuals' characteristics, circumstances, and preferences. We refer to this endeavor as "individualized health." The present article comprises 2 sections. In the first, we describe how graphical, longitudinal, and hierarchical models can inform the project of individualized health. We propose a simple graphical model for informing individual health decisions using population-based data. In the second, we review selected topics in causal inference that we believe to be particularly useful for individualized health. Epidemiology and biostatistics were 2 of the 4 founding departments in the world's first graduate school of public health at Johns Hopkins University, the centennial of which we honor. This survey of a small part of the literature is intended to demonstrate that the 2 fields remain just as inextricably linked today as they were 100 years ago.

Mechanistic Models of Infectious Disease and Their Impact on Public Health.

From the 1930s through the 1940s, Lowell Reed and Wade Hampton Frost used mathematical models and mechanical epidemic simulators as research tools and to teach epidemic theory to students at the Johns Hopkins Bloomberg School of Public Health (then the School of Hygiene and Public Health). Since that time, modeling has become an integral part of epidemiology and public health. Models have been used for explanatory and inferential purposes, as well as in planning and implementing public health responses. In this article, we review a selection of developments in the history of modeling of infectious disease dynamics over the past 100 years. We also identify trends in model development and use and speculate as to the future use of models in infectious disease dynamics.

The Role of Professional Journals and Societies in the Future of a Field: A Reflection on the Partnership Between the American Journal of Epidemiology and the Society for Epidemiologic Research.

On this, the 100th anniversary of Johns Hopkins Bloomberg School of Public Health, we take the opportunity to reflect on the ties between the School, the American Journal of Epidemiology, and the Society for Epidemiologic Research. We discuss briefly the intersection of the School, the Journal, and the Society throughout their histories, with the aim of providing some insight into how the Journal and the Society have contributed to the evolution of the field. In so doing, we articulate the challenges that the Journal and the Society jointly face today, with an eye to finding opportunities in these challenges that can be helpful in coming decades.

Health services management and research at Nordic School of Public Health.

In Anglo-Saxon countries the subject of health services research has long been an important academic theme. In the Nordic countries, however, this research and training area has been limited and partly hidden by integration into various other sections at universities and colleges. In this respect the Nordic School of Public Health was an exception, as the provision of managerial skills to healthcare professionals and persons working with public health was the backbone of the school during all 60 years. A variety of research in health services management, as well as publications of text books, accompanied the presented courses. Several of the scholars have earned important positions in international networks and editorial boards, as well as in boards for assessments of research grants. In the near future, this academic field will require alternative support.

How to create and terminate a school of public health.

The famous preamble to the Constitution of the World Health Organization (WHO) from 1948, stating that health is not only the absence of disease, has been one of the most influential political statements of our time. The follow-up, reaching a position where health is viewed as instrumental to a good life and not as a goal in itself, as set out in the Ottawa Charter of 1986, has likewise been of the utmost importance for the global development of public health, as well as developing the concept of health promotion. The focus on public health sparked by the WHO was paralleled by expansion of the academic interest in the topic, beginning in the USA and successively adopted around the world. In the Nordic countries the pioneering of an academic platform for public health studies and research began in 1953. This was later followed by a stepwise expansion to a full academic institution with postgraduate studies, work-related training, research and development. From the start, the resultant institution called the Nordic School of Public Health (NHV) was a joint Nordic project financed by the Nordic governments. The NHV became a leader in public health studies in Nordic countries and also a role model for the development of an academic community. A large campus and a select and erudite staff, together with thousands of students, paved the way for the NHV having a major impact on public health policy in Nordic countries. One effect of this was increasing awareness of the need for systematic policy supporting public health research and, with this, the founding of institutions of public health in all of the separate Nordic countries. Ironically, the impact made by the NHV in spreading the idea of public health as an important part of academic study has made the NHV superfluous. It is true that courses and programmes in public health are now available at most universities in the five Nordic countries, but they are directed at young students fresh from high school. There is no institution that offers a broad and high-quality postgraduate education and training in public health, adapted to the special needs of mid-career professionals in a multi-professional and internordic setting. With the NHV closing, a research institute focusing public health in a Nordic context will disappear, as will an internationally leading School of Public Health, a centre of excellence and relevance in public health, which has evaluated, assessed and promoted the goals and evaluated the success of the Nordic welfare societies.

NHV and child public health.

One of the main interests of the Nordic School of Public Health (NHV) in both education and research was child public health, i.e. an area based on the broad World Health Organisation (WHO) health ideology and on public health methods, while concentrating on the special needs and characteristics of children. The fields of study and action, training, research and service, had the ultimate task to consider the health of children in their full social, economic and political context. Regular courses on child public health were offered as part of the general program in Public Health from 1979 until the closing down of the school, named: Social Paediatrics; Child Health; Child Public Health; and finally, Measuring Children's Health - A Public Health Perspective. Numerous national, Nordic and international conferences were held, and several textbooks were written and edited. A major research project, NordChild, was initiated as a cross-sectional postal study of a random sample of children aged 2-17 years from the five Nordic countries, performed in 1984, 1996 and 2011. So far, 10 doctoral theses and more than 130 other publications from the studies have been produced. Furthermore, the Nordic Network on Research of Refugee Children was created, and a special interest has been devoted to indicators for children's health, both internationally, nationally and locally, which has been demonstrated in major EU projects as well as locally in Sweden and Greenland.

The Nordic Health Promotion Research Network (NHPRN).

The Nordic Health Promotion Research Network (NHPRN) was established in 2007 at the Nordic School of Public Health (NHV). This article aims to describe the foundation of the NHPRN, the development and the present status of the work of NHPRN. The NHPRN consists of about 50 senior and junior researchers from all Nordic countries. It is a working network that aims to develop the theoretical understanding of health promotion, to create research cooperation in health promotion from a Nordic perspective and to extend the scope of health promotion through education. Network members meet biannually to discuss and further develop research within the field and are also responsible for the Nordic conference on Health Promotion, organized every 3 years. The NHV hosted the network between 2007 and 2014; and the World Health Organisation (WHO) will assume this role in 2015.

Health Promotion: A developing focus area over the years.

In 1953 when the Nordic School of Public Health was founded, the aim of public health programmes was disease prevention more than health promotion. This was not unusual, since at this time health usually was seen as the opposite of disease and illness. However, with the Ottawa Charter of 1986, the World Health Organization made a crucial change to view health not as a goal in itself but as the means to a full life. In this way, health promotion became a first priority and fundamental action for the modern society. This insight eventually reached NHV and in 2002 - 50 years after the foundation - an associate professorship was established with a focus on health promotion. Nevertheless, the concept of health promotion had been integrated with or mentioned in courses run prior to the new post. Subsequently, a wide spectrum of courses in health promotion was introduced, such as 'Empowerment for Child and Adolescent Health Promotion', 'Salutogenesis--from theory to practice' and 'Health, Stress and Coping'. More than half of all doctoral theses undertaken at NHV during these years had health promotion as their theme. As a derivative, the Nordic Health Promotion Research Network (NHPRN) was established in 2007 with bi-annual meetings at NHV.

Healthy ageing, narrative method and research ethics.

The purpose of this article is to describe research and teaching activities related to healthy ageing, narrative methods and research ethics at the Nordic School of Public Health NHV during 1999 - 2012. Healthy ageing was conceived in terms of The World Health Organization's (WHO) model of active ageing and of quality of life defined as a sense of well-being, meaning and value. Qualitative research on ageing and health conducted at NHV showed how elderly people themselves experience health and what they perceive to be health promoting. Narrative method was one the qualitative methods used in research at NHV. By adopting holistic and categorical content analysis the life stories of elderly Finnish migrants, the stories of home-dwelling persons about falls, and working persons' stories of alcohol use were studied. The courses on research ethics took their point of departure in a model that describes the role of scientific, economic, aesthetic and ethical values in research.

Method development at Nordic School of Public Health NHV: Phenomenology and Grounded Theory.

BACKGROUND: Qualitative methods such as phenomenology and grounded theory have been valuable tools in studying public health problems. AIM: A description and comparison of these methods. RESULTS: Phenomenology emphasises an inside perspective in form of consciousness and subjectively lived experiences, whereas grounded theory emanates from the idea that interactions between people create new insights and knowledge. Fundamental aspects of phenomenology include life world, consciousness, phenomenological reduction and essence. Significant elements in grounded theory are coding, categories and core categories, which develop a theory. CONCLUSIONS: There are differences in the philosophical approach, the name of the concept and the systematic tools between the methods. Thus, the phenomenological method is appropriate when studying emotional and existential research problems, and grounded theory is a method more suited to investigate processes.

Pharmacoepidemiology at Nordic School of Public Health NHV: Examples from 1999 to 2014.

BACKGROUND: Pharmacoepidemiology is a branch of public health and had a place at the Nordic School of Public Health. Courses, Master's theses and Doctorates of Public Health (DrPH) in Pharmacoepidemiology were a relatively minor, but still important part of the school's activities. METHODS: This paper gives a short background, followed by some snapshots of the activities at NHV, and then some illustrative case-studies. These case-studies list their own responsible co-authors and have separate reference lists. RESULTS: In the Nordic context, NHV was a unique provider of training and research in pharmacoepidemiology, with single courses to complete DrPH training, as well as implementation of externally-funded research projects. CONCLUSIONS: With the closure of NHV at the end of 2014, it is unclear if such a comprehensive approach towards pharmacoepidemiology will be found elsewhere in the Nordic countries.

On education and pedagogic development at NHV.

The role and development of the Nordic School of Public Health (NHV) during its 60 year existence with special emphasis on the pedagogical basis (Scandinavian pedagogy) of courses, the student population, cross-borders incorporation of staff and professional and institution identity-creation through storytelling.

Epidemiology and statistics at the Nordic School of Public Health: Teaching and research 1979-2014.

The Nordic School of Public Health (NHV) was jointly founded in 1953 by the Nordic countries. Until 1979, the school provided ad hoc courses on public health topics, using external teachers drawn mainly from the Nordic countries. At the time, the permanent staff of the school was small. In 1979, it began a Master's degree programme and a few academic positions were established and filled, to support these courses. The programme included four main areas: Epidemiology, Social Medicine, Environmental Health and Health Services Administration. Epidemiology was compulsory in all Master of Public Health (MPH) exams, but there were a handful of optional courses that could be substituted for the other subjects.This paper tells the story of Epidemiology at NHV from about 1980, up until closure of the school in 2014. The original MPH model ran until 1995. Nursing Science entered NHV from about 1985 and worked mainly with qualitative research that often focused on individual patients. The new methods attracted nurses, midwives, psychologists and other groups that previously had been less represented in NHV. Being quantitative and population oriented, Epidemiology lost its unique position as a mandatory subject for the MPH examination. In addition the 'New Public Health' proposed by the World Health Organisation (WHO) that advocated health promotion and the philosophy of salutogenesis became a challenge for the programme in epidemiology: pathogenesis no longer was of primary interest. From 1995, the MPH format changed repeatedly and a DrPH programme was begun. For the last 8 years of its existence, NHV offered a reasonably comprehensive, basic course in Epidemiology.Throughout the years, epidemiology training and research at NHV were very traditional. In being a relatively free institution in terms of academic choices, NHV should have contributed to the development and innovation of epidemiology in public health. For several reasons, this did not happen.

Nordic School of Public Health NHV and its legacy in global health.

This article describes the legacy of the Nordic School of Public Health NHV (NHV) in global health. We delineate how this field developed at NHV and describe selected research and research training endeavours with examples from Vietnam and Nepal as well as long-term teaching collaborations such as BRIMHEALTH (Baltic RIM Partnership for Public HEALTH) in the Baltic countries and Arkhangelsk International School of Public Health in Russia.

Contribution of the Nordic School of Public Health to the public mental health research field: a selection of research initiatives, 2007-2014.

The field of public mental health has been defined by an expert group convened by the Nordic School of Public Health (NHV) as encompassing the experience, occurrence, distribution and trajectories of positive mental health and mental health problems and their determinants; mental health promotion and prevention of mental disorders; as well as mental health system policies, governance and organization. The mental health priorities of the Nordic Council of Ministers in 2010 signalled a mutual Nordic exchange of knowledge in the following thematic areas: child and adolescent mental health; working life and mental health; mental health in older people; strengthening the role of primary care in mental health service provision; stronger involvement of users and carers; and reduction of use of coercion in psychiatric care. Efforts to realize these priorities included commissioning the Nordic Research Academy for Mental Health, an NHV-based network of research institutions with a common interest in mental health research across the Nordic countries, to develop, organize and follow-up projects on public mental health. The research initiatives included mental health policy analysis, register-based research and research focused on the users' perspective in a Nordic context, as well as EU-level research policy analysis. The public mental health research conducted at the NHV highlighted the complexity of mental health and emphasized that the broad determinants of mental health need to be increasingly addressed in both public health research and practice. For example, health promotion actions, improved access to health care, a healthy alcohol policy and prevention of suicides and violence are all needed to reduce the life expectancy gap - a red flag indicator of public health inequalities. By exchanging knowledge and best practice, the collaboration between the Nordic countries contributes to the welfare of the region. The expertise and traditions developed at the NHV are of significant importance in this work.