Putting prevention into practice
What is prevention?
Prevention in healthcare is the concept of avoiding diseases through leading a healthy life. It includes a wide range of activities, such as eating well, having vaccinations and undergoing screening tests for cancers.
The general issue with prevention is that most of us do not think about it. We are generally focused on short-term priorities. Even though we know we should prepare for events that lie in the years ahead, we struggle to make them a priority in our lives and act in a preventative way.
Prevention applies to all individuals - even for those with a pre-existing medical condition. It is broadly divided into:
Primary prevention - preventing a condition before it happens. For example, having a vaccine to prevent chicken-pox.
Secondary prevention - preventing complications from a pre-existing condition. For example, taking aspirin to prevent further heart attacks.
Tertiary prevention - reducing the impact of complications from a pre-existing condition. For example, physical therapy after having a stroke.
The importance of prevention
Benjamin Franklin famously said "an ounce of prevention is worth a pound of cure". In many cases, preventing disease and disability is preferable to ongoing treatment of conditions.
For an individual, thinking and acting preventatively about health can have many types of benefits. These can include (depending on the type of health issue prevented):
- A longer life;
- A better quality of life;
- Avoiding pain and suffering;
- Time and money saved;
- Avoiding putting loved ones through discomfort or suffering due to one's premature death or disability, and;
- For infectious diseases, avoiding passing the disease to others.
Worldwide, one in two adults will have a chronic condition in their lifetime.  However, the majority (75%) of chronic conditions can be prevented.  If even a portion of this number can be prevented, there would be significant savings to overall healthcare costs and reduce strain on many health services.
Types of prevention
1. Early detection
A crucial part of prevention is identifying any health problems at an early stage, as they are starting to develop - or even before that. Early detection of health problems can generally allow for complete treatment and improved outcomes.
Health problems can be identified at an early stage through using screening tests. Screening tests are specific investigations designed to detect a particular condition in people who have not yet developed any symptoms (i.e. at an early stage). Generally, a large population of people are recommended to have these tests to identify the few people who are at-risk of developing the condition. Examples of screening tests are mammogram (for breast cancer), pap smears (for cervical cancer), and fecal occult test (for bowel cancer).
2. Health maintenance
Our human bodies need regular upkeep to work properly. We evolved in an environment where food was scarce and physical activity was a necessary fact of survival, and our bodies developed to reflect this: your body is calibrated to move a lot every day, to extract as much energy from food as possible, and to require a wide range of foodstuffs.
Now, however, most of us are living a life that our bodies are not accustomed to: an environment where food is plentiful and easy to obtain, and physical activity is a leisure activity. This means that more people than ever are eating far too much than is healthy for them, and moving far too little.
We now know that the effects of a sedentary life and a poor diet are serious and far-reaching. These 'lifestyle' issues can be a struggle for many of us, but it is clearly beyond doubt that what we eat and how much we exercise have a huge effect on our health and our life expectancy. A 'Western' diet heavy in fats and sugars, overweight, and lack of exercise are all strongly linked to a large number of serious, disabling, life-threatening and life-shortening health conditions.
Vaccinating people against infectious disease has arguably proven to be the most effective preventative measure ever. In the US, since the introduction of vaccinations for children, deaths from vaccine-preventable disease have fallen by 99%. Worldwide, it is estimated that vaccination programs have prevented approximately three million deaths each year. 
For more information, see our report on childhood immunizations.
4. Injury prevention
Injury is a major cause of preventable death in the US. There are over 30 million visits to emergency departments in the US due to injuries, mainly due to falls and transport accidents. Other causes for injuries include domestic violence, sporting and recreational activities, and work incidents.
Most injuries, regardless of accidental or intended, can be prevented by understanding the causes of most injuries and acting to reduce these.
5. Mental health and wellbeing
Mental illness that includes anxiety disorders, depression and substance-abuse disorders is a major cause of health problems in the US with around 26% of American adults aged 18 years and older suffering from a diagnosable mental disorder in a given year. Mental illness results in significant health, social and economic and productivity consequences and is likely to increase in future years.
There are several government programs designed to support people with mental health conditions. These programs are designed to increase access to age-appropriate mental health services, better support suicide prevention, and increase awareness about mental health issues.
6. Prevention during early years of life
Prevention is needed for all age-groups, but is particularly important from early life to avoid lifelong health conditions. Having access to good pregnancy care, education about parenthood, and a supportive, nurturing environment are all important for healthy childhood development. An example of prevention during early years of life is the regular monitoring of children's development through measurement of their growth, language and movement skills (which is usually done by a maternal and child health nurse) to detect any early developmental delays and allow for treatment.
Future of prevention
The future of prevention in health is largely related to advances in technology. Better screening tests, more affordable diagnostic equipment, and leveraging smartphones in conveying health promotion is likely to improve current prevention methods. Personalizing prevention, particularly using genetics, as well as making it predictive (i.e. knowing years in advance before an individual develops a condition) are the ultimate aims for prevention.
Policy and culture
The benefits of preventive medicine are gradually sinking in: the consequences of unhealthy behaviors such as smoking and eating bad diets are becoming increasingly clear. As the population in many countries ages, and the incidence of preventable chronic illnesses such as diabetes rises, people and societies the world over are beginning to realize the costs of treating these illnesses, and turn to preventive health as the preferable alternative.