Cancer Genetics Risk Assessment and Counseling (PDQ®): Genetics - Health Professional Information [NCI] - The Option of Genetic Testing
Table 1. Clinical Utility of Genetic/Genomic Testsa continued...
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 1,087 users of Facebook, a social-networking Web 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 of 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 how 145 Facebook users interpreted DTC information. Participants completed an online survey in which separate scenarios containing information derived from DTC Web sites about the risk of developing heart disease, colorectal cancer, or basal cell skin cancer were presented. The authors found that even in this highly educated cohort, of whom 56% were in the health care field, the reported ease of understanding the test results was not related to an accurate interpretation of the results. Of those who answered that the results were easy or very easy to understand for each of the scenarios, correct interpretation varied greatly (59%–80%) across the four scenarios.