The new tool, described in PLoS Medicine, presents the risks and benefits of these different options in the form of a roulette wheel. The patient spins the wheel, and can then directly visualize the chances of a particular treatment leading to benefit or harm.
The researchers, led by Jerome Hoffman, show how the roulette wheel could help a healthy 65-year old man decide whether or not to be screened for prostate cancer (the screening test is a blood test called the PSA).
By spinning the roulette wheel, the man sees that if he decides to get a PSA test, he may slightly lower his risk of dying from prostate cancer but he also greatly increases the chances of becoming incontinent and/or impotent from prostate cancer treatment. The roulette wheel shows him that his chances of developing symptoms of prostate cancer are very small, whether or not he gets screened.
"Shared decision making has largely been adopted as an ideal way for physicians and patients to join together whenever there are decisions that need to be made about management of health care issues," say the researchers.
But one of the problems with shared decision making, they say, is that physicians have traditionally presented the risks and benefits of different treatments in the form of numbers, which many people have trouble understanding. "It is hard for anyone to comprehend the difference between a 7% chance and an 8% chance," they say, "and this is exacerbated when we try to deal in more extreme probabilities, such as 3 in 10,000."
The researchers believe that the roulette wheel could be an important advance in shared decision making because patients are offered visual--rather than numerical--displays of the probability of benefits and harms.