Whenever a decision must be made about diagnosis or treatment, two tasks must be accomplished. The first is to choose information resources that are most appropriate to help determine the best course of action. The second is to apply what is learned to the person's situation.

There are several challenges. One challenge is time. Many decisions must be made quickly. Doctors and people with medical conditions may not have enough time to gather and evaluate all the information available. Another challenge is quality of information. Not all information or recommendations in books, web sites, and even published research studies are correct. Other information may be correct but apply only to some people and not to others. Doctors must help people weigh the quality of information. For example, doctors may feel that their personal experience merits more trust than information gleaned from some Internet sources.

Doctors must judge the potential effects of any diagnostic recommendations. They must help people weigh the consequences of overlooking a serious condition even if the diagnosis is unlikely.

The same type of reasoning is used in deciding about treatments. Doctors will probably not recommend treatments that may have serious side effects for people who have a mild condition. Conversely, if the condition is grave but cure is possible, potential side effects may be worth the risk.

Doctors and the people they are treating may not share the same perceptions of risk. A person who hears about a possible serious side effect of a drug may be very concerned, regardless of how rarely the side effect occurs. The doctor may not be as concerned if the possibility of that side effect is remote. Or the doctor may not understand that what might seem to be a relatively minor side effect for most people may cause great problems for a particular person. For example, a person who drives for a living may be more concerned about taking a drug that can cause drowsiness.

Often, the balance between the risk of the disease and its treatment is not clear-cut. A doctor may judge the risks and benefits of a treatment differently than the person being treated does. People should discuss these differences in judgment with their doctors. Understanding risks can also help a person weigh options. A doctor may outline several approaches and ask the person to help decide among them. By evaluating the relative and absolute risks of the various choices and then factoring in personal values, a person can make more informed choices about medical care.

Last full review/revision June 2007 by Thomas V. Jones, MD, MPH