The entrepreneurial nature of the US health care system coupled with technical advances greatly decreasing the cost of genome scanning have created a market for direct-to-consumer genome-wide scanning for disease risks. These tests, which purport to identify relative risk for 20-40 diseases, are typically priced at $400-2,000. Proponents of the tests, aside from their obvious profit motive, claim that they help patients track their health more carefully, following screening recommendations and making better lifestyle choices; while opponents claim they have little clinical utility, are disconnected from the patient’s physician, may cause undue anxiety and lead to unnecessary tests or procedures. Research published in the New England Journal of Medicine attempts to evaluate the effects of DTC genetic testing. (NEJM Article)
A commercial test was used by the approximately 2000 subjects, with results provided in the form of lifetime and average risks. Genetic counselors were also made available by the testing company. The subjects were surveyed at baseline and at two follow-up periods. The study outcomes were changes in exercise, changes in dietary fat, changes in anxiety level and test-specific stress and use of screening tests. Overall, no significant change was noted from baseline to follow-up in regard to level of anxiety, dietary fat intake or amount of exercise. Ninety percent plus of the participants had no significant test-related distress. Overall the participants were evenly divided on whether they intended to follow-up with more medical screenings or tests, although people with higher risk scores were more likely to indicate an intent to have more tests and a few individuals indicated they would seek many more tests.
Only 10% of subjects took advantage of the free opportunity to discuss the results with a genetic counselor and only 26% did discuss the results with their physician, which may support the concern about such testing being disconnected from overall care. The group that talked with their physicians, however, did reduce fat consumption and get more exercise. Of some note is that 44% of the initial participants did not complete the study. These persons may have been more anxiety-prone or had other concerns about the testing. Overall, the research suggests that while DTC testing may not have many adverse effects, it also does little good and so is basically a waste of time and money for the patients choosing it.