What is Public Health?

What is Public Health?


As a public health student, I am often asked what public health is and even though I have studied the subject for several years, I still struggle to find an answer. Sure, I could offer a definition of it, the same WHO definition that has been presented to me in every public health class I have attended, but it does not effectively capture the necessity of it or how it differs from primary health care. When asked what public health is, what I want to offer is a simple example. And, while reading Factfulness by Hans, Anna, and Ola Rosling, I was introduced to a short story that does just that.


WHO’s Definition of Public Health


Public Health is the art and science of preventing disease, prolonging life and promoting health through the organized efforts of society.


As far as definitions go, the WHO’s definition of public health is a good one. It is short and easy to understand. The issue, however, is that it results in more questions. How does public health prevent disease, prolong life and promote health? What are the organized efforts of society? And how is public health both an art and a science? Furthermore, how does that differ from primary health care? I mean, when you go and see your doctor, do they not want to prevent you from getting a disease? Do they not want to prolong your life and promote your health?


Definitions often leave me confused or wanting more. And in the case of the WHO’s definition of public health, that is exactly how I feel. And, it is safe to assume that, someone who does not know what public health is will feel the same.


Hans Rosling’s Story About the Deaths We Do Not See


First off, let me just say that I think everyone should read Factfulness: Ten Reasons We're Wrong About the World — and Why Things Are Better Than You Think. It is a book about perception, and it aims to correct our view of the world. The main message of the book is that things are not as bad as we think, or as bad as the media portrays them. This is something we should all be reminded of — to think critically.


In chapter 5, Hans tells a story about his experiences as a young doctor in Mozambique in the early 1980s — during a time where Mozambique was the poorest country in the world. Hans, and one other doctor, served a district of 300,000 people and admitted 1,000 sick children each year with diseases like diarrhea, pneumonia, and malaria. Of these 1,000 children, 50 would end up dying; which almost equates to one child dying each week.


One weekend, a friend of Hans visited him and his wife — a fellow doctor, albeit one from a bigger city and a better provisioned health care centre. That Saturday Hans received an emergency call to the hospital and his friend joined him. The emergency was a sick baby with severe diarrhea who had been brought to the hospital by a scared mother. Hans admitted the child, inserted a feeding tube, and told the nursing staff that an oral rehydration solution be given through the tube. This treatment did not sit well with his friend who argued that it was substandard and that the baby should be given an intravenous drip.


Hans’ response was: “This is our standard treatment here. It would take me half an hour to get a drip running for this child and then there would be a high risk that the nurse would mess it up.” A brutally honest answer that his friend could not accept. His friend decided to stay at the hospital and struggle for hours to get a needle into the tiny vein of the baby.


When his friend had joined Hans back at home their argument continued. His friend insisted that, as a doctor, Hans must do everything he can for every patient that enters his hospital. Again, Hans responded with a brutally honest answer, one that perfectly captures the necessity of public health: “It is unethical to spend all my time and resources trying to save those who come here. I can save more children if I improve the services outside the hospital. I am responsible for all the child deaths in this district: the deaths I do not see just as much as the deaths in front of my eyes.”


Public Health vs. Primary Health Care


Hans’ friend was not satisfied with his response, nor would any primary health care doctor be, but given the situation Hans was presented with, he was right. The next day Hans set out to prove his position on the subject by collecting data on the child deaths in his district and doing some simple math. He already knew that 50 children died each year that had been admitted to the hospital, what he needed was the number of children who died each year that had not been admitted. Using the child death rate of Mozambique as a reference and the number of child births in the district, Hans calculated that 3,900 children died each year, of which only 50 happened in the hospital. In other words, primary health care was trying to prevent the deaths of 50 children, while public health (if it had existed in the district) would be trying to prevent the deaths of 3,850 children.


Armed with this information, Hans and his wife set out to improve the health of the district by employing simple public health practices such as training village health care workers, educating parents, and vaccinating children. In other words, Hans was attempting to prevent disease, prolong life and promote health in order to deal with the 3,850 child deaths in the district, rather than commit all his time to preventing the 50 child deaths in the hospital.


Public Health is a Necessity


Now, do not mistake my support for public health as an attack on primary health care, that is not my intention, nor was it Hans’ intention. Society needs both public health and primary health care. In fact, they go hand-in-hand. But if public health can prevent sickness outside the hospitals, primary health care will be less overwhelmed trying to treat it.