One of the major themes of this meeting is personalized medicine – the promise that some day, doctors will be able to tailor treatments for all of us based on our genetic makeup. Scientists and researchers are excited about the future prospects of personalized medicine, but there are also huge questions about how useful it will really be. Social scientists are wondering: can patients can handle genetic information? Will they overreact upon learning they have some small increase in risk for a disease? Or will the information wash over them like the myriad public service announcements exhorting us to eat right and get more exercise – messages that, apparently, most of us have learned to ignore?
Researchers are starting to get some answers on these questions by studying patients in Detroit, Michigan’s Henry Ford Health System in a study called the Multiplex Initiative, funded by the U.S. National Human Genome Research Institute. In it, doctors offer a bundle of genetic tests to healthy patients aged 25-40. They then follow the patients to see who goes on to take the tests – which are packaged together in a so-called “multiplex” assay that surveys risk variants in 15 different genes – and what they do with that information. This multiplex test simulates, on a much smaller scale, the consumer genetic tests sold by private companies, which survey hundreds or thousands of risk variants across the genome.
So far, the NHGRI’s data hints that some of the worst fears about genetic testing might not come to fruition.
For instance, NHGRI’s Colleen McBride said that one of the strongest factors that predicts which patients choose to take the multiplex test was how much the patient believed that behavior contributes to overall risk of disease. Those who believed more strongly that behavior contributes to disease – that smoking, not just genetic makeup, affects the risk of lung cancer, for example – were more likely to get tested. McBride’s interpreted this finding to mean that the patients wouldn’t believe that they were powerless to do anything about their disease risk if they got a “high risk” test result. And, conversely, they might be more motivated to change their behavior by a multiplex test result.
And Robert Reid of Group Health Cooperative in Seattle said that patients who took the multiplex test made slightly more visits to their primary care doctors in the 18 months after getting their test results than they had in the 18 months prior to taking the test. But even though the increase was significant, it was still a small increase in sheer number of visits. What’s more, the number of screening tests ordered on the patients didn’t increase after the genetic tests were completed.
And McBride noted that of the patients who got tested, only 11 percent actually discussed their results with their doctors; an additional 14 percent planned to.
According to Reid, this contradicts the fear that patients will overreact to their genetic tests results, causing wasteful spending on a glut of unnecessary follow-up medical work. “We are certainly not finding a stampede of visits to primary or specialty care following multiplex testing,” he said.
So it seems – at least from this very preliminary data – that people are better at using genetic information to inform their health decisions than some might have feared. If the finding holds up, it will correlate well with other studies of reactions to genetic testing, such as a study published earlier this year, which found that genetic testing for Alzheimer’s disease risk didn’t hurt patients’ mental health.
There was, however, some data to suggest that other concerns about genetic testing might be more salient. For instance, the patients who eventually got the multiplex test were more likely to be white than black, perhaps substantiating the fear that testing will not reach everyone equally.
It’s hard to say what this means for the personal genomics tests sold to consumers, though. The Multiplex Initiative requires patients to at least visit a web site, prepared by the project, that is intended to be educational rather than promotional. The site even gave reasons why patients might decide against testing, and described the limitations of the tests. That’s different in a pretty important way from the information provided by personal genomics companies: the companies obviously believe that the tests are useful – and are motivated to convince consumers that this is, indeed, the case. So it’s unclear whether the lessons from the Multiplex Initiative will apply to the “wild west” of commercial personal genomics.