Prevention includes a wide range of activities — known as “interventions” — aimed at reducing risks or threats to health. You may have heard researchers and health experts talk about three categories of prevention: primary, secondary and tertiary. What do they mean by these terms?
Primary prevention aims to prevent disease or injury before it ever occurs. This is done by preventing exposures to hazards that cause disease or injury, altering unhealthy or unsafe behaviours that can lead to disease or injury, and increasing resistance to disease or injury should exposure occur. Examples include:
- legislation and enforcement to ban or control the use of hazardous products (e.g. asbestos) or to mandate safe and healthy practices (e.g. use of seatbelts and bike helmets)
- education about healthy and safe habits (e.g. eating well, exercising regularly, not smoking)
- immunization against infectious diseases.
Secondary prevention aims to reduce the impact of a disease or injury that has already occurred. This is done by detecting and treating disease or injury as soon as possible to halt or slow its progress, encouraging personal strategies to prevent reinjury or recurrence, and implementing programs to return people to their original health and function to prevent long-term problems. Examples include:
- regular exams and screening tests to detect disease in its earliest stages (e.g. mammograms to detect breast cancer)
- daily, low-dose aspirins and/or diet and exercise programs to prevent further heart attacks or strokes
- suitably modified work so injured or ill workers can return safely to their jobs.
Tertiary prevention aims to soften the impact of an ongoing illness or injury that has lasting effects. This is done by helping people manage long-term, often-complex health problems and injuries (e.g. chronic diseases, permanent impairments) in order to improve as much as possible their ability to function, their quality of life and their life expectancy. Examples include:
- cardiac or stroke rehabilitation programs, chronic disease management programs (e.g. for diabetes, arthritis, depression, etc.)
- support groups that allow members to share strategies for living well
- vocational rehabilitation programs to retrain workers for new jobs when they have recovered as much as possible.
To help explain the difference, take this example. Let’s say you are the mayor of a town near a swimming hole used by kids and adults alike. One summer, you learn that citizens are developing serious and persistent rashes after swimming as a result of a chemical irritant in the river. You decide to take action.
If you approach the company upstream that is discharging the chemical into the river and make it stop, you are engaging in primary prevention. You are removing the hazardous exposure and preventing rashes in the first place.
If you ask lifeguards to check swimmers as they get out of the river to look for signs of a rash that can then be treated right away, you are engaging in secondary prevention. You are not preventing rashes, but you are reducing their impact by treating them early on so swimmers can regain their health and go about their everyday lives as soon as possible.
If you set up programs and support groups that teach people how to live with their persistent rashes, you are engaging in tertiary prevention. You are not preventing rashes or dealing with them right away, but you are softening their impact by helping people live with their rashes as best as possible.
For many health problems, a combination of primary, secondary and tertiary interventions are needed to achieve a meaningful degree of prevention and protection. However, as this example shows, prevention experts say that the further “upstream” one is from a negative health outcome, the likelier it is that any intervention will be effective.
Source: At Work, Issue 80, Spring 2015: Institute for Work & Health, Toronto [This column updates a previous column describing the same term, originally published in 2006.]