A risk factor is a trait or behavior that increases the likelihood of contracting or developing a disease or other health condition. Health conditions can include physical disease and mental disorders, as well as injury from dangerous behaviors like impaired driving. Some risk factors can be changed through lifestyle choices, while others, such as genetics or gender, cannot. The risk factor has a number of applications in public health, health care, and some industries such as insurance. It is also an important basis for preventive care.
In mental and physical health, the presence of a risk factor can help to guide treatment plans. This may depend on whether it can be changed and how strongly it's related to the condition. When it is not known exactly how a risk factor affects a certain condition, it may be less useful in treatment. Nevertheless, finding risk factors is an important part of preventing health conditions they are definitely known to cause. One such case is the relationship between smoking and lung cancer.
One example of how risk factors are used is the Framingham heart score. This checklist helps to determine the risk of heart attack over the next 10 years. Individual risk factors on this list include age, two different cholesterol scores, and blood pressure. These scores are then compared to separate charts for males and females and help estimate heart attack risk. The heart score is the product of a study that was important in developing the idea of the risk factor itself.
Common categories of risk factors include lifestyle decisions, environmental factors, and access to health care. Other schemes exist for labeling different types of risk factors. Sometimes genetics includes family history, or lifestyle choices such as diet and exercise could be considered separately. A different term may be used if a person already has an existing disease that makes getting another one more likely. Risk factors in a category like lifestyle choices can be changed, while those in the genetics or family history categories cannot.
In the language of statistics, a risk factor is a variable that increases the probability that a certain event may happen. They are based on statistical measures that have been collected from historical research or from ongoing studies. Drawing on earlier work done in the field of statistics, researchers began considering risk in the 20th century. This included academic research as well as a great deal done by insurance companies. This was important for guiding insurance companies in the creation of health and life insurance polices, for instance.