The principal difference between public health and clinical medicine is that public health focuses on the whole population, whereas clinical medicine focuses on an individual. The steps in a public health approach are to define and monitor the problem (using data from different sources); identify risk and protective factors; develop and test prevention strategies; and assure widespread adoption.

Presenting Complaint

Public health tends to focus on people who are well with the aim of keeping them well, hence the focus on prevention as a pillar of public health. An arm of public health takes the prevention approach one step further down the disease pathway, to look to make diagnoses of disease early and before any symptoms develop where early treatment can lead to significantly better outcomes for individuals, so called secondary prevention or screening.

The Diagnosis

In public health, information is gathered through epidemiology. Epidemiology includes quantitative and qualitative data, and these are supplemented by information from affected communities. The focus in this data collection is to understand the causal origin of a health issue, including both risk and protective factors, and to think about and explicitly test what might work as an intervention.

The Focus of Treatment

Public health focuses on distal causes. These distal causes are often the real drivers of ill health at the population level, such as employment conditions, educational attainment, living conditions, poverty, and discrimination.

Public health small shifts in many individuals can bring about large shifts in population health as a collective. Further, public health focuses on shifts in the environment (physical, social, cultural), making it easier for people to make healthy choices. These changes are achieved through changes to legislation, regulation, policy, media/communications, and sometimes programs, creating a health supporting environment rather than focusing on the behavior of individuals.

The Cure

In public health, there needs to be an explicit process of evaluative thinking, thinking through the logic of how the proposed intervention will interact with the cause at the population level, through to the associated outcomes, and these will be measured through a formal evaluation.

The Multidisciplinary Team

In public health we can think about this as working with our partners. The levers for the causal factors for most cases of ill health are distributed across society, with a very strong influence of local, state, and federal governments on the environments in which we live. There is a wealth of literature on how best to partner in public health settings which are directly relevant to the work of the social services.

Taking Cholera as an Example: A Public Health Approach

Cholera, a deadly intestinal illness, was widespread in London during the early nineteenth century, leading to the deaths of tens of thousands. At the time, it was commonly believed that the disease was caused by poor air quality from decaying organic material. John Snow is renowned for his efforts to identify the source of the cholera outbreak and is regarded as a pioneer of modern epidemiology.