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Disease Prevention

In this series of articles, medical students from across the country will discuss a range of topics from medical ethics to the NHS to public health to medical conditions to clinical governance.

These articles give you an overview of the principles; understanding the overlap between topics will allow you to develop a more detailed insight into medicine.

The World Health organisation defines disease prevention as “specific, population-based and individual-based interventions for primary and secondary (early detection) prevention, aiming to minimize the burden of diseases and associated risk factors.”

The terms primary, secondary and tertiary prevention were first documented in the late 1940s by public health pioneer’s Leavell and Clarke.

Primary disease prevention = Actions to prevent the disease from happening in the first place. This prevention is to lower the incidence of disease (the number of new cases). An example of primary prevention is immunizations, such as the influenza vaccine which is available every year on the NHS to help protect adults and children at risk of flu.

Secondary disease prevention = Actions taken to diagnose the disease early and result in prompt treatment. Screening programmes, such as the NHS breast cancer screening programme, are examples of this.

Tertiary disease prevention = Actions taken to minimise suffering and improve quality of life. It is the prevention of a disability (a lack of ability to perform an activity in ways that are considered normal for a human being resulting from an impairment) becoming a handicap (the negative impact of the disability which limits or prevents fulfilment). An example of this is a stroke rehabilitation program.

⚕️ Disease Prevention vs. Health Promotion

Disease prevention and health promotion share many of the same goals. They differ in that disease prevention focuses on specific efforts to reduce the development and severity of disease directly, whilst health promotion aims to indirectly reduce disease by encouraging healthy behaviours.

Health promotion is defined by the World Health Organisation as:

“The process of enabling people to increase control over, and to improve, their health. It moves beyond a focus on individual behaviour towards a wide range of social and environmental interventions.”

#Epidemiologist Geoffrey Rose's published the Sick individuals and sick populations paper 1985. Here he described two types of population approaches;

The “high risk” approach to disease prevention: A prevention strategy of targeting individuals identified (e.g. thorough screening) as having elevated risk for some adverse health outcome
The “population strategy” approach to disease prevention: A strategy of prevention that targets the whole population regardless of the individuals’ risk status. This approach aims to shift the distribution of disease risk factors bell curve to the left.

🤝Prevention Paradox

Geoffrey Rose also described the prevention paradox in 1981. The paradox describes the contradictory situation where the majority of cases of a disease come from a population group at low or moderate risk of that disease, and only a minority of cases come from the high risk population. For example, most babies born with Down Syndrome come from young mothers but the most at risk are older mothers, it is just because young women are more likely to have children. The paradox means that when governments or organisations introduce a large scale intervention to improve health, there are large overall health gains for the whole population but only small advantages to each individual.