Levels of Prevention

Public health focuses on the prevention of disease rather than the diagnosis and treatment of diseases. Here are some resources to help us better understand this concept of prevention. 

Levels of prevention

Within public health, prevention activities are categorized across three levels; primary, secondary, and tertiary.

Primary prevention aims to promote the health of whole populations by taking action to prevent illnesses or injuries before they occur. This is called an 'upstream' approach that uses universal and targeted approaches to support and promote good health across the life span. Health Promotion operates in the realm of primary prevention.

Secondary and tertiary prevention are considered more 'downstream' approaches to health. These approaches involve acting after illness or injury has occurred through measures like early detection, treatment, and management of chronic disease and disability.  Screening, to identify diseases in the earliest stages, occurs at the secondary level and managing disease post diagnosis to slow or stop further progression of the disease is tertiary prevention.

Health impact pyramid

The Health Impact Pyramid describes five levels of intervention (i.e., actions, programs, or policies) to prevent poor health outcomes and promote well-being.  The levels are organized according to the individual effort required and the interventions' ability to change population-level conditions. According to the model, the two are inversely related (i.e. interventions that require the most individual effort have the least potential to create population-level change).

"Upstream" prevention

Upstream prevention, also known as primary prevention, helps people stay healthy by preventing illness and injury, promoting healthy environments, and addressing social injustice. It focuses on prevention and the root causes of poor health (e.g., through policies and creating supportive communities/surrounding environments). 

Downstream reaction focuses on responding to individual health needs (e.g., treatment and emergency care). By investing resources and energy upstream (e.g., tobacco legislation and smoking cessation), we can help to reduce the burden on our health system by keeping people healthy and preventing people from needing health services, where possible (e.g., treatment and management of COPD). 

In health promotion, we work "upstream" to help prevent illness and injury before they actually occur, and to support a healthy, thriving Island population. 

The Upstream-Downstream story

If we look closer at the river, the image depicts a classic public health tale, where a witness sees someone caught in a river current 'downstream'. They quickly jump in the river to save that person, only to find more and more people drowning in the river. After many rescues, the witness decides to walk 'upstream' to investigate why so many people are falling into the river in the first place. 

This story is meant to illustrate the tension between the need to respond to immediate health needs and emergencies (in this case, downstream where people are caught in the river current and drowning) and allocating resources to prevention and promotion, and understanding the root causes (in this case, the upstream factors and preventing people from ever falling into the river). 

This is where the work of health promotion lies: stopping people from falling in the river in the first place and preventing or delaying their journey downstream to where they make contact with our healthcare system. 

Upstream work is about addressing the things that have the greatest influence on our health, which are not actually our individual behaviours or our healthcare services, but instead things like income, employment, education, early childhood development, housing, nutrition and our surrounding environments (e.g., physical infrastructure, healthy public policies, supportive communities). These social determinants of health are what make the greatest difference in health outcomes at a population level and addressing these determinants enables people to live longer and healthier lives.