In medicine, prevention is any activity which reduces the burden of mortality or morbidity from disease. This takes place at primary, secondary and tertiary prevention levels.

1. Primary prevention avoids the development of a disease. Most population-based health promotion activities are primary preventive measures.
2. Secondary prevention activities are aimed at early disease detection, thereby increasing opportunities for interventions to prevent progression of the disease and emergence of symptoms.
3. Tertiary prevention reduces the negative impact of an already established disease by restoring function and reducing disease-related complications.

[edit] Difference between preventions, treatments, and cures

A prevention or preventive measure is a way to avoid an injury, sickness, or disease in the first place, and generally it will not help someone who is already ill (though there are exceptions). For instance, many American babies are given a polio vaccination soon after they are born, which prevents them from contracting polio. But the vaccination does not work on patients who already have polio. A treatment or cure is applied after a medical problem has already started.

A treatment treats a problem, and may lead to its cure, but treatments more often ameliorate a problem only for as long as the treatment is continued. For example, there is no cure for AIDS, but treatments are available to slow down the harm done by HIV and delay the fatality of the disease. Treatments don't always work. For example, chemotherapy is a treatment for cancer which may cure the disease sometimes - it does not have a 100% cure rate. Therefore, chemotherapy isn't considered a bonafide cure for cancer.

Cures are a subset of treatments that reverse illnesses completely or end medical problems permanently.

In the area of substance-related harms, a number of prevention typologies have been proposed.

Gordon (1987) in the area of disease prevention, and later Kumpfer and Baxley (1997) in the area of substance use proposed a three-tiered preventive intervention classification system: universal, selective and indicated prevention. Amongst others, this typology has gained favour and is used by the US Institute of Medicine, the NIDA and the European Monitoring Centre for Drugs and Drug Addiction.

1. Universal prevention addresses the entire population (national, local community, school, district) and aim to prevent or delay the abuse of alcohol, tobacco, and other drugs. All individuals, without screening, are provided with information and skills necessary to prevent the problem.
2. Selective prevention focuses on groups whose risk of developing problems of alcohol abuse or dependence is above average. The subgroups may be distinguished by characteristics such as age, gender, family history, or economic status. For example, drug campaigns in recreational settings.
3. Indicated prevention involves a screening process, and aims to identify individuals who exhibit early signs of substance abuse and other problem behaviours. Identifiers may include falling grades among students, known problem consumption or conduct disorders, alienation from parents, school, and positive peer groups etc.

Outside the scope of this three-tier model is Environmental prevention. Environmental prevention approaches are typically managed at the regulatory or community level, and focus on interventions to deter drug consumption. Prohibition and bans (e.g. smoking workplace bans, alcohol advertising bans) may be viewed as the ultimate environmental restriction. However, in practice environmental preventions programmes embrace various initiatives at the macro and micro level, from government monopolies for alcohol sales, through roadside sobriety or drug tests, worker/pupil/student drug testing, increased policing in sensitive settings (near schools, at rock festivals), and legislative guidelines aimed at precipitating punishments (warnings, penalties, fines).

[edit] See also

• Preventive medicine
• Risk factor

[edit] Sources and notes

• Gordon, R. (1987), ‘An operational classification of disease prevention’, in Steinberg, J. A. and Silverman, M. M. (eds.), Preventing Mental Disorders, Rockville, MD: U.S. Department of Health and Human Services, 1987.
• Kumpfer, K. L., and Baxley, G. B. (1997), 'Drug abuse prevention: What works?', National Institute on Drug Abuse, Rockville.