Consumers who typically pay $400-$2,000 to obtain their genetic risk profiles via the Internet appear to change very little after reading the results, at least in the short term, according to a Jan. 12 report in the New England Journal of Medicine.
In a prospective study involving 3,639 participants who chose to obtain direct-to-consumer, genomewide risk profiling with a commercially available test, there were no measurable changes in anxiety level, dietary fat intake, or exercise level – markers of change in health behavior – or in the use of screening tests for health disorders in the 3 months after they received their results.
In addition, only 10% of the subjects consulted with a genetic counselor, even though there was active outreach from the counselor and services were provided free of charge. A total of 26% reported sharing their results with their physician, according to Cinnamon S. Bloss, Ph.D., of Scripps Genomic Medicine and Scripps Health in La Jolla, Calif., and her associates.
The study participants are still being followed to track their longer-term psychological and behavioral responses during the next year. Meanwhile, "generally speaking, our findings support the null hypothesis (that provision of the results of a direct-to-consumer genomic risk test does not affect health-related behavior), but the potential effects on the population at large are still unknown," the investigators noted.
The clinical validity and utility of genomewide profiling have never been demonstrated. Proponents have argued that consumers who purchase the test may become more compliant with health-screening practices and adopt more healthful lifestyles. Opponents have argued that instead, such testing may raise consumers’ anxiety and boost their use of unnecessary and expensive medical screening and procedures.
To examine this issue, Dr. Bloss and her colleagues performed an ongoing, longitudinal, cohort study in which subjects were assessed at baseline and at 3 months to measure changes in their anxiety symptoms and behavior after profiling. All subjects purchased the genomewide risk profiles at a subsidized cost and were offered free genetic counseling in exchange for their participation.
Only 2,037 subjects completed the 3-month follow-up. A total of 55 completed the baseline health assessment but withdrew from the study, 223 never submitted a sample for genetic testing or never viewed their results, and 1,310 viewed their results but were lost to follow-up. "The failure of a large percentage of subjects (44%) to complete the study is notable," the researchers said.
"We found no evidence that learning the results of genomic risk testing had any short-term psychological, behavioral, or clinical effects on the study subjects," they said (N. Engl. J. Med. 2011 Jan. 12 [doi:10.1056/NEJMoa1011893]).
Overall, the participants showed no discernible change in anxiety level, according to measurements on the Impact of Events Scale–Revised or the Avoidance and Intrusion subscales of this anxiety-screening tool. More than 90% of subjects had low scores indicating no test-related distress, and more than 97% had low scores indicating no clinically significant test-related distress.
However, it is possible that subjects who may have been harmed psychologically by the testing are the ones who declined to participate in the first place, or who dropped out, Dr. Bloss and her associates noted.
The study subjects also showed no change in dietary fat intake or exercise level.
Subjects also did not pursue screening for a variety of disorders that their genetic profiles may have prompted, including thyroid testing, colonoscopy, cholesterol screening, cardiac stress testing, mammography, prostate-specific antigen testing, eye exams, or blood tests for numerous diseases that have a genetic component.
"This may be a good thing, given that the majority of the screening tests we assessed are considered inappropriate for asymptomatic persons. In most instances, the use of such tests would probably result in a waste of health care resources," the researchers said.
This study was limited in that it involved selected subjects and was of longitudinal design so it did not include a control group. Moreover, "the subjects in our study are clearly not representative of the broader U.S. population, and we therefore cannot draw conclusions about the effect of genomewide testing on the population at large," Dr. Bloss and her colleagues said.
The study was funded by the National Institutes of Health’s National Human Genome Research Institute and National Center for Research Resources, as well as by the Scripps Genomic Medicine division of Scripps Health. No financial conflicts of interest were reported.