Studies Address Impact of DTC Genetic Testing

Consumers buying direct-to-consumer personal genome tests (DTC-PGT) want to believe good news, according to an article published in the September issue of Nature Biotechnology. While participants’ perception of their personal risk changed after receiving results showing decreased and increased risk, there was an “optimism bias”—with a greater change in perception resulting from good news. Additionally, the researchers found that following receipt of PGT results, consumers primarily seek medical attention in response to large, surprising results.

Despite high-profile regulatory scrutiny of DTC-PGT, there is not much evidence showing how use of these services impacts consumers’ medical decision making.

The researchers modeled risk perception as a combination of baseline beliefs and learning in response to genetic news. Health care utilization was assessed as a function of changes in these risk perceptions. The study included consumers enrolled in the Impact of Personal Genomics (PGen) study, a longitudinal study of real DTC genomics customers. The researchers found that participants had a slight “optimistic bias” in perception of baseline risk. Following receipt of test results, showing “good news”—a decreased risk of a condition—consumers showed a significantly bigger drop in risk perception compared to the relative increase in risk perception following the receipt of “bad news” or results showing an increased risk of disease.

A separate study, also involving the PGen Study Group, found that pharmacogenomic results indicating an atypical drug response are common among patients requesting DTC-PGT. Receipt of these results is associated with prescription medication changes, although less than one percent of DTC consumers report unsupervised changes to their prescription medications six months following testing.

For further discussion of these studies, see the November 2016 issue of Diagnostic Testing & Emerging Technologies.