The Option of Genetic Testing
There is growing interest in trying to use genetic information to guide decisions about healthy lifestyle, including dietary choice, although there is no evidence base for implementing such practices. A 2006 study of consumer and physician awareness of DTC nutrigenomic tests found that 14% of consumers and 44% of physicians had heard of the tests, but actual utilization was exceedingly low (0.6% of consumers had used one). This study examines awareness of nutrigenomic testing in Michigan, Oregon, and Utah via the 2006 Behavioral Risk Factors Surveillance System. Awareness was highest in Oregon (24.4%) and Utah (19.7%) and lowest in Michigan (7.6%). Those who had higher incomes, greater education, and increasing age (except those older than 65 years) were more aware of nutrigenomic tests. Of those consumers who had heard of DTC nutrigenomic tests, 46% had heard about them from television, 35% from magazines, 29% from newspapers, and only 13% from health professionals. There was great variation in the extent to which background information concerning the disease in question was presented. For example, more than half of these companies offered information about disease etiology, but far fewer offered information about diagnosis and treatment or prevention. Companies providing tests of little clinical utility (such as enhancement tests) tended to provide more detailed information, although the information provided about the diseases and genetics in general was not always accurate, as clinical validity claims were supported by peer-reviewed literature in only approximately half the companies. The trend identified in this survey of available companies indicates that the tests with the least clinical utility are provided with the least professional oversight and counseling services.
A study of 1,037 users of a social networking site who proactively registered with a marketing firm indicated that almost half of respondents were aware of personal genetic testing (PGT). Fewer than 10% of respondents had used PGT for a variety of conditions, including but not limited to cancer; however, the majority indicated that they would consider using PGT (64%). The study also identified key areas in which individuals may benefit from additional education and information. For example, one-third of respondents mistakenly understood that the PGT results indicated a diagnosis of disease as opposed to risk for developing disease. In addition, respondents viewed physicians as an important resource in understanding and using PGT results to make health care decisions.
Another study examined perceptions and attitudes about DTC in a sample of 3,640 health care, technology, and biotechnology employees who purchased a DTC personalized genomic risk test (offered at a discounted rate). Approximately half of those surveyed expressed overall concerns about undergoing testing. Females and individuals employed by a health care organization were more likely to express concern; higher education, younger age, and higher levels of anxiety were also associated with concerns about testing. All those surveyed were open to receiving information about the risk of unpreventable disease.