WASHINGTON – Few physicians feel prepared to interpret the findings from direct-to-consumer genetic tests and incorporate the results into clinical practice, according to speakers at a National Academy of Sciences workshop on DTC genetic testing.
“There's a lot of confusion between these services and medical care,” said Dr. Patricia Ganz. DTC companies may say that test results are for educational and research purposes only and that they cannot be used for diagnostic purposes because the tests have not been validated for clinical use, but the results are “in fact being very much treated as medical information.”
The difference between how the tests are marketed and what's feasible in clinical practice point to a “number of risks to the clinical encounter,” said Dr. Ganz, professor of health services and medicine at the University of California, Los Angeles. Possible problems include a demand for screening tests that have no proven clinical value, the perception that a physician is unsympathetic or lacking in knowledge when reviewing a patient's DTC genetic test report, and a false sense of security when a test result indicates “low risk.”
Published reports indicate that physicians obtain most of their information about DTC genetic testing through the media, Katrina Goddard, Ph.D., of the Kaiser Permanente Center for Health Research, Portland, Ore., said at the workshop.
In the same reports, national surveys of consumers in the same periods showed that 14% were aware of the tests covered in the 2006 survey, and 22% were aware of the tests in the 2008 survey, but less than 1% used the tests.
Nearly half of the physicians who said that they were aware of DTC genetic tests said they had patients with questions about the tests. About 15% of these physicians had at least one patient who brought in their test results for discussion. Some aspect of the patient's care changed in 75% of these encounters, according to the survey.
Physicians who search for resources to help in interpreting DTC test results are likely to turn to point-of-care clinical decision tools. But current versions of these tools often lack relevant information and are inefficient to use, said Joseph McInerney, who serves as director executive director of the National Coalition for Health Professional Education in Genetics.
A study of two open-access and seven general-subscription genetics resources online found that in answering four clinical questions about each of five common genetic conditions, the resources provided complete information only one-third of the time, and in just as many instances provided no information (Genet. Med. 2008;10:659-67).
These results may reflect deficiencies in training in clinical genetics, he said.
Dr. Ganz noted that when physicians advise patients about their DTC test results, it is unclear if the addition of genetic information to family history actually promotes appropriate behavior change.
“We need scientific guidance on these tests that can be linked to effective screening strategies. I think doing them in isolation and not doing studies to see if it changes behavior or changes outcome is false advertising,” commented Dr. Ganz.
None of the speakers disclosed conflicts of interest with DTC genetic testing companies.
“We need scientific guidance on these [DTC] tests,” says Dr. Patricia Ganz.
Source Courtesy UCLA