One of the concerns with direct-to-consumer genetic testing is that no one knows whether people will understand their disease risks or how they will react to what they find out. Two recent studies found that early adopters of DTC genetic testing have a moderately good understanding of their risks and that some were even motivated to change their behaviors, as researchers reported at the American Society of Human Genetics meeting in Washington, DC, last month.
"Our research only scratches the surface of what the concerns are," noted David Kaufman from the Genetics and Public Policy Center at Johns Hopkins University.
Kaufman's team, which conducted an NHGRI-funded survey of 1,048 people who had purchased a DTC test from 23andMe, DecodeMe, or Navigenics, reported that nearly everyone indicated that the risk reports they received from the companies were easy to understand, though some overestimated their understanding of the results. The group also asked respondents to interpret data for two fictitious people to gauge their understanding of the risk reports. Between 4 percent and 7 percent of the respondents misinterpreted what they saw, Kaufman said.
Another study — based on a series of 60 interviews with Coriell Personalized Medicine Collaborative program participants — found similar results: most people had a good idea of what their results meant, though some people had difficulties deciphering relative disease risks, according to the University of Pennsylvania's Barbara Bernhardt, who led the study.
Kaufman said that just more than three-quarters of his team's survey respondents said that they ordered the test to improve their health, and some of the respondents said that they'd been motivated to modify their behaviors in light of their test results: 15 percent changed medications or supplements, and 14 percent began exercising more.
The Coriell team found that a slightly higher proportion of people — about a third — were motivated to change their behaviors in response to what they'd learned, though Bernhardt said that most made only slight changes, such as increasing an existing exercise regimen or taking additional vitamins. (Though one person quit smoking and another became a vegan.) "We did not see evidence of false reassurance" in regards to disease risk, she added.
Kaufman said that further study is necessary to determine whether these behavioral changes will be maintained over the long term.
Both researchers noted that their study participants were early adopters of the technologies and thus were primarily white and tended to have higher levels of education and income than the general population.