Medicine saves lives one at a time. Public Health saves lives by the millions.
In many countries, the guilds of the medical fraternity provide for specialist membership. Attached to membership is prestige, promotion, and increased earning potential. In almost all cases, membership or fellowship of one of these guilds, typically titled “Colleges”, indicates increased expertise in the management of classes of disease in individual patients.
If you have diabetes, atrial fibrillation, Parkinson’s disease, major depression, etc., or you need more or less specialised surgery, you may well want to consult a member of one of these guilds of medicine.
The focus of Public Health is the protection and improvement of the health of populations. The breadth of public health practice is enormous with individuals working in disease specific areas (e.g., HIV, TB, or mental health); settings (e.g., schools, workplaces, markets); social policy areas of the social determinants of health; health systems; health financing and market regulation; urban design; and health data analytics, to name just a few. Although there are commonalities between them, Public Health may be contrasted with Community Medicine and Social Medicine by the fact that Public Health practitioners do not spend their time treating individual patients, although they may guide services for the better and more efficient treatment of populations of patients.
The most significant distinction is that Public Health draws its expertise from a wide range of disciplines: behavioural sciences, nursing, management, geography, history, politics, anthropology, environmental sciences, urban planning, sociology, pharmacy, economics, biostatistics, microbiology, ecology, mathematics, parasitology, computer science, entomology, engineering, veterinary science, … and medicine. Some of the best public health people I have ever worked with have come from history and geography. It is not that history and geography are peculiarly crucial to Public Health. It is that good Public Health requires interdisciplinary teams that can bring new perspectives to problems. It is relatively unusual to find historians and geographers in Public Health, so they bring novel solutions that are quite different from those one might otherwise see.
Postgraduate Public Health training, such as a Masters of Public Health (MPH), is a useful way of providing the diverse disciplines involved in Public Health a common language with which to share problems, ideas, and solutions. There is no one best discipline for Public Health, and there is no reason that one has to study Public Health formally to make a valuable contribution to Public Health practice. I speak here as a person who has no formal qualification in Public Health but one who has been a Professor of Public Health, has lead Public Health teams, and has advised governments, UN agencies and international NGOs on Public Health.
I return to my titular point. Public Health benefits enormously from the input of people with a diverse range of qualifications. What then is the purpose of a medical specialisation in Public Health, if Public Health is not a branch of medicine?
The answer is historical and political. The historical answer is that Public Health is traditionally located within the Ministry of Health (MOH). There is a logic to this. So much of the practice of Public Health is about the coordination, regulation and efficient delivery of health services that it must be coordinated with MOH activities. The obvious down-side of this historical location of Public Health is that, as it has become increasingly evident that population health problems require whole of government approaches, any attempts to transcend the departmental pillars of government are regarded by other Ministries as a MOH power-grab.
Politically, power within MOH is typically vested in people with membership in one of the specialist guilds of medicine. The only way for Public Health to have status in MOH (and let’s face it, Public Health has never been as sexy as clinical medicine) is for it to be lead by people with a medical qualification and membership of a specialist guild. Thus, specialist guilds of Public Health medicine were born.
This historical and political strategy protected the status of Public Health within MOH. It provided a career pathway for medically qualified personnel interested in pursuing a career in Public Health. Unfortunately, it also limited the capacity of Public Health practice to deliver the best population health outcomes.
Governments need to improve the way they approach the protection, promotion and improvement of the health of their populations. A good start is to recognise that medicine is a part of the practice of Public Health (just as history, geography, etc. are), but Public Health is much bigger than a specialisation of medicine.