Your Medical Mind_ How to Decide What Is Right for You - Jerome Groopman [25]
This divide between doctors’ and patients’ preferences has been studied in depth in treatment of another problem, atrial fibrillation, the condition that affected Dave Simon. This abnormal cardiac rhythm is very common: About 1 percent of Americans in their fifties suffer from it, and 5 to 10 percent of those who are seventy or older do. Based on data from the Framingham Heart Study, it is estimated that over the course of a lifetime, atrial fibrillation or a related rhythm called atrial flutter will occur in about 25 percent of the population. It can be the first sign of hyperthyroidism, especially in the elderly.
Atrial fibrillation occurs when the upper part of the heart called the atrium contracts abnormally, so that the heart beats in a disorganized and irregular way. Blood can pool in the heart, and clots can form. These clots can then be pumped out to the body and result in a stroke. Patients with atrial fibrillation are often treated with “bloodthinning” medications called anticoagulants, like warfarin or aspirin, that help prevent clots from forming. But these treatments can cause profuse bleeding. Such hemorrhaging is most common in the gastrointestinal tract but can be particularly devastating when it occurs in the brain. So the patient with atrial fibrillation must choose whether to take medication that may prevent a stroke from a clot but can cause serious bleeding.
Researchers at Dalhousie University in Nova Scotia interviewed sixty physicians who were treating patients with atrial fibrillation. They also interviewed a similar number of patients who did not have atrial fibrillation but were at high risk for developing this condition. Each doctor and each patient was asked to consider treatment options for a theoretical group of one hundred patients who had atrial fibrillation: Options included no therapy, aspirin, or warfarin. Both the doctors and the patients were presented the same numerical information about the chances of stroke and bleeding for each option and then were asked if the treatment was justified. The patients placed significantly more value or “utility” on avoiding stroke, while the physicians placed more value on avoiding bleeding. Although there was no information about why the doctors valued the risks and benefits of the treatment differently from the patients, the researchers concluded, “The views of the individual patient should be considered when decisions are being made about treatment for people with atrial fibrillation.”
Researchers at the Ottawa Hospital in Canada similarly studied nearly two hundred patients from sixty to eighty years old who didn’t have atrial fibrillation but were likely to develop the condition in the future. These patients were asked to imagine that they themselves had atrial fibrillation and to consider if they would take anticoagulants for it. One group received information using qualitative language, where risk of stroke or bleeding was designated as either “low” or “moderate.” The other group received detailed quantitative data on stroke and bleeding risks, carefully framed in both positive and negative ways—for example, “3 out of 100 chance of stroke, meaning 97 out of 100 chance of not having a stroke with treatment.”
In this study, patients given the most detailed information chose what researchers termed “the extremes” of treatment; more participants chose either the potent anticoagulant warfarin or no treatment at all rather than the middle-of-the-road option, aspirin. Giving more exact and understandable clinical information