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NHGRI Study Suggests DTC Genetic-Risk Testing Motivates Consumers to Improve Health


By Turna Ray

A behavioral study by researchers from the National Human Genome Research Institute and several other institutions found that consumers who have received their genetic risk assessments through the web may improve their health outcomes through a more informed interaction with their doctors.

"Individuals who present to healthcare providers with online genetics information may be among the most motivated to take steps toward healthier lifestyles. These motives might be leveraged by healthcare providers to promote positive health outcomes," concluded researchers led by Colleen McBride, chief and senior investigator of the Social and Behavioral Research Branch at NHGRI.

The findings from this study, published in Genetics in Medicine earlier this month and called the Multiplex Initiative, may help healthcare providers better address the needs of those who use the online services of direct-to-consumer genomics firms, according to the researchers.

"Direct-to-consumer availability of genomic testing profiles gives health consumers new health information that as yet has no established clinical utility," the study authors said. "Understanding early adopters’ motives for seeking testing can be informative to physicians in managing patients who present with genomic profiles."

The Multiplex Initiative, launched in 2006, is one of the first studies to look at people's attitudes toward genetic risk information for common preventable conditions [see PGx Reporter 03-26-2008]..

Most behavioral studies on genetic testing have focused on rare hereditary diseases, where study participants were recruited from families with a high risk for these diseases. "Thus, not surprisingly, these individuals typically report perceiving themselves to be at high risk for these conditions and to feel concerned that they may be at
genetic risk," the study authors noted.

As a result, the results from these previous studies "may not generalize to the context of genetic testing for common health conditions in healthy individuals where gene variants act together with environmental and behavioral risk factors to increase risk, and genes alone confer relatively modest increases in risk, usually on the order of 20 percent and 30 percent."

The aim of the Multiplex Initiative was to investigate what factors contributed to study participants' interest in and decision to take a multiplex genetic susceptibility test for eight common health conditions. "Our intent was to educate a representative sample of individuals about genetic testing while assessing their social, psychological, and behavioral characteristics," the authors wrote in the paper. "This enabled us to compare the characteristics of the sizable group who chose not to be tested with those who requested testing."

In the observational study, McBride and her team enrolled adults aged between 25 and 40 years who were part of large managed-care organizations. Study participants could log on to a secure study website where they could learn the risks and benefits of obtaining their genetic disease-predisposition, and request free testing.

Out of 6,348 individuals contacted for the study, approximately 31 percent, or 1,959 individuals, were eligible and completed the baseline survey. Of the remaining participants, 1,292 declined to complete the baseline survey, 2,614 were unreachable despite up to 10 repeated attempts, and 326 did not meet study criteria. Approximately one-third of individuals who completed the survey were college graduates and white, 46 percent were male, and 63 percent were married. On average, participants had three health conditions for which the project was offering multiplex genetic testing.

The project offered testing for 15 genetic polymorphisms associated with increased risk for eight "preventable" and common conditions, including type 2 diabetes; lung, colon, and skin cancer; coronary heart disease; hypercholesterolemia; hypertension; and osteoporosis. Researchers defined as "preventable" conditions, those for which there are "widely accepted evidence-based prevention recommendations."

A total of 612 individuals who completed the baseline survey visited the study’s website to consider testing and 528 registered a test decision. Of these, 266 provided written consent and had blood drawn for multiplex testing, while 261 decided not to go forward with testing.

According to the study results, study participants who considered getting online genetic risk assessments "did not hold genetically deterministic beliefs but believed genetic information to be valuable and were confident they could understand such information."

In the study, those most likely to get genetic testing and report the most lifestyle changes were those who felt it was important to increase their genetic knowledge, and "felt confident they could understand genetics," the researchers found.

Critics of online DTC genetic testing have suggested that providing genetic risk information directly to consumers, without the mediation of a doctor, could confuse people and cause them anxiety about the future of their health.

However, according to this study, "participants generally rated behavior as a greater causal factor than genetics for seven of the eight health conditions" being tested for. "Participants tended to believe that common health conditions could be attributed relatively equally to genes and behavior," the study authors said.

These considerations did not impact participants’ decision to log on to the website and get tested. "Considering it to be important to learn about genetics predicted participants’ logging on and getting tested," the study authors said.