Before recommending treatment, doctors weigh the potential risk of harm from a treatment against its potential benefit. (See also Overview of Medical Decision Making and The Science of Medicine.)
Balancing Risks and Benefits
Health care professionals use their education, experience, and the results of clinical trials to provide information regarding the risks and benefits of available treatments.
Risk is the likelihood that a harmful outcome will occur, such as worsening of the disease or developing a side effect from the treatment. How risks are described can make a big difference. For example, suppose that there was a clinical trial that compared a new medication to prevent stroke against an established medication. Now suppose the results of the trial showed that the new medication caused the side effect of bleeding in 2% of people but the established medication caused bleeding in 1% of people.
One way to state the results would be to say that the new medication caused "twice as much bleeding" (the relative risk increase).
But it would be equally correct to say that the new medication "increased the possibility of bleeding by only 1 percentage point" (the absolute risk increase).
In this example, the relative risk being twice as high makes the new medication sound extremely dangerous, whereas the absolute risk increase of 1 percentage point makes the danger sound minimal. And people who are for or against something typically quote only the risk description that best fits their opinion. Doctors can help people understand risk estimates and make a reasoned decision.
The benefit of treatment could be any of the following:
Cure of the disease (the greatest benefit and ultimate goal)
Decreased symptoms (for example, reduced pain)
Improved function (for example, being able to walk farther)
Decreased likelihood of disease complications (for example, heart attack in people with diabetes)
After weighing the risks and benefits of treatment and taking into account a person’s goals and preferences, the doctor might make a recommendation for a specific treatment plan. However, this process can sometimes be complicated, because
There may not be one best treatment for a disease
The tradeoffs between the risks and benefits may be numerous and confusing to sort through
Providing Perspective
Because medical information can be complex, health care professionals should provide perspective on the potential risks and benefits. For example, in the United States, advertisements for various medications are accompanied by a long list of potential side effects that range from mild to disastrous, but these advertisements do not provide information on any of the following topics:
How many people will experience these side effects
The consequences of these side effects
The consequences of not treating the disease
As a result, a person who might benefit greatly from a treatment might refuse the medication for fear of experiencing any number of the advertised side effects (which may occur in, for example, 1 out of 100 people).
For example, many people who have high blood pressure stop treatment because they have side effects from the medication they were given. Doctors can explain to people that even though they feel fine now, treating high blood pressure is important because it significantly reduces their chance of heart attack, stroke, and kidney failure, which are leading causes of death and disability in the United States. If people understand that side effects might be avoided or minimized by using a different medication or a different dose, they might be more willing to assume the risks of treatment. By contrast, the effects of a heart attack or stroke are often serious, irreversible, and life-threatening, meaning that the potential benefit of taking a blood pressure medication greatly outweighs the potential risks for most people.
Doctors can also provide perspective by comparing the person's circumstances with the circumstances of the people in whom a medication or treatment was originally studied in a clinical trial. For example, a person who is sicker than the people in whom the medication was originally studied might benefit less from the medication and perhaps experience more risk. On the other hand, a person who is healthier than the people in whom the medication was originally studied might have better outcomes than those of the study group.