Public Health - The Basics

There are many definitions of Public Health, but here are some to start with:

Public Health was defined by Acheson as 'The art and science of preventing disease, prolonging life and promoting health through the organized efforts of society', and this is probably the most commonly used short definition.

A longer version is: 'Public health is the science and art of preventing disease, prolonging life and promoting physical health and efficacy through organized community efforts for the sanitation of the environment, the control of communicable infections, the education of the individual in personal hygiene, the organization of medical and nursing services for the early diagnosis and preventive treatment of disease, and the development of social machinery which will ensure every individual in the community a standard of living adequate for the maintenance of health; so organizing these benefits in such a fashion as to enable every citizen to realize his birthright and longevity.' (Winslow - see Towards a common definition of global health).

The role of public health is to 'contribute to the health of the public through assessment of health and health needs, policy formulation, and assurance of the availability of services'. (Institute of Medicine (1988) The future of public health. Institute of Medicine, Washington, DC.). The IOM further defined the mission of Public Health as 'fulfilling society's interest in assuring conditions in which people can be healthy'

Other than the definitions given above, here is another one: "Use of theory, experience and evidence derived through the population sciences, to improve the health of the population in a way that best meets the implicit and explicit needs of the community (the public)" - this definition is designed to help Public Health practitioners interpret their role (and thus their educational requirements) (Heller et al Public Health 2003:117;62-5). As we will see in the various Topics in this module, the area is challenging as practitioners require many skills - all required to understand and improve the health of the population.

Which brings us to the population. The population is the focus of Public Health, and Population Health is defined by the Public Health Agency of Canada as: "Population health is an approach to health that aims to improve the health of the entire population and to reduce health inequities among population groups. In order to reach these objectives, it looks at and acts upon the broad range of factors and conditions that have a strong influence on our health." see What is the population health approach from the Public Health Agency of Canada, which defines the key elements of the population health approach - 1. Focus on the health of populations; 2. Address the determinants of health and their interactions; 3. Base decisions on evidence; 4. Increase upstream investments; 5. Apply multiple strategies; 6. Collaborate across sectors and levels; 7. Employ mechanisms for public involvement; 8. Demonstrate accountability for health outcomes.

Public Health approach. This graphic (from Ian Rockett Descriptive Epidemiology for Public Health professionals) describes the Public Health approach:

From Rockett: Descriptive epidemiology for public health professionals.

Note: Although step three of this graphic includes evaluation of the intervention, we might add a further evaluation step, after the implementation. We could convert the model into a cycle, where evaluation follows the implementation and becomes part of the surveillance before we go round again, making improvements each time.

Another figure is reproduced below from the US Centers for Disease Control and Prevention (CDC) Public Health Approach.

From Centers for Disease Control and Prevention (CDC).

The importance of including this picture is to emphasise that research is an important part of the Public Health approach - in order to obtain appropriate evidence for action

Finally. Although there is really no difference between 'Public' and 'Population' Health, and the various definitions may appear to be just semantics, consideration of the population is important, as the scientific underpinning of this area depends on measuring and intervening on populations rather than individuals.