More than a third of individuals completing direct-to-consumer (DTC) genetic tests share their results with their own physician within a year, and this sharing is associated with higher screening test completion, according to a study published online April 4 in the Journal of Medical Genetics. Additionally, there doesn’t seem to be any negative long-term psychological impact from DTC testing, whether or not results are shared. The researchers say that their findings suggest that potential test regulation mandating physician participation as a gatekeeper is unnecessary.
While debate still lingers over the clinical utility and clinical validity of commercial genomic risk testing for common disease, the researchers sought empirical data to assess the psychological, behavioral, and clinical impact that testing had on participants in the year following receipt of results. The researchers studied a longitudinal cohort study of adults who purchased the Navigenics Health Compass with surveys at baseline (2008 to 2009), short (three months), and long term (one year following receipt of test results). Long-term follow-up was completed by 1,325 participants.
There were no significant detrimental psychological effects from receiving test results nor were there significant improvements in lifestyle behavioral factors. Specifically, at long-term follow-up there were no significant differences from baseline in anxiety, fat intake, or exercise. Nearly 97 percent of participants had no test-related distress.
Although there were no significant differences in the total number of screening tests completed or intended to be completed between short- and long-term follow-up, a consistent 42.4 percent of the sample reported at long-term follow-up that there was at least one or more screening tests they intended to complete with greater frequency post-genomic testing. Screening test completion was significantly associated with sharing genomic test results with a physician and perceived utility of the test (61.5 percent perceived high utility). Just over 14 percent of participants reported discussing their results with a Navigenics genetic counselor, and 39.5 percent reported sharing their results with their own physician or health care provider.
Composite measures of genetic risk were not significantly associated with long-term follow-up anxiety, test-related distress, fat intake, exercise behavior scores, or total number of screening tests completed. However, there was a significant association between composite measures of risk and total number of screening tests participants intended to complete with greater frequency.
“It is noteworthy that a very large fraction of our long term follow-up sample also reported perceiving that they generally understood their test results and that the test had high personal utility. . . . This, coupled with the lack of adverse psychological outcomes observed, is consistent with ongoing direct access by patients to genomic testing, assuming appropriate regulatory oversight is in place,” write the authors, led by Cinnamon Bloss, Ph.D., from Scripps Translational Science Institute in La Jolla, Calif.