Precision Medicine: Are Primary Care Providers Prepared to Interpret Genetic Testing Results?

Specialists might be the best choice to interpret genetic testing results, but primary care providers may be positioned to do so when specialists are not available, a new study has found. And that is a finding of enormous importance given the inexorable rise of genomic testing and precision medicine.

The Diagnostic Challenge

Interpreting the results of genetic testing has become the domain of a specialized group of genetic counselors and clinical geneticists. But because these specialists are so few in number and spread so thin, the concern is that they will be quickly overwhelmed by the sheer volume of genetic data that requires analysis. The problem will become even more intense if and when today’s direct-to-consumer genetic testing, which is largely not covered by health insurers, becomes accepted as a mainstream part of treatment. All of this raises an important question: Are primary care providers ready, willing and able to fill the void?

The Study

A team of researchers led by Biomedical Informatics Ph.D. Dr. Scott McGrath set out to answer that question by surveying 664 medical professionals, including both genetic specialists and primary care providers, about their feelings on deciphering genetic data for their patients. Did they feel comfortable with and capable of making an accurate assessment and explaining the results to patients? Respondents were asked to interpret genetic data under three scenarios:

• A scenario based on a 23andMe risk report on the genetic susceptibility to diabetes of a 35-year-old obese man;
• A scenario based on a Pathway Genetics drug response result for statin-induced myopathy for a man taking simavastatin to control his cholesterol; and
• A more complex scenario based on a report from Geisinger’s COMPASS genomic testing tool involving symptoms and a genetic sequencing test result involving DCTN1 variants linked to distal hereditary motor neuronapathy type VIIB, for a 48-year-old woman with three children.

The Findings

The study, described in BMC Health Services Research, found that both specialists and primary care providers had generally high accuracy rates in interpreting the results of the three scenarios, with specialists averaging 83.4 percent correct and other primary care providers averaging 74.4 percent correct. Based on the relatively small magnitude of difference between the groups, the researchers concluded that primary care providers might, in fact, be able to interpret genetic testing results correctly when specialists are not available. Other key findings:

• Specialists were more confident than primary care providers in their ability to interpret testing results;
• While respondents from both groups were more likely to stumble on the third scenario involving a rare disease, specialists performed better in handling that scenario;
• Providers with genetic testing experience were twice as likely to correctly interpret the three scenarios;
• Younger providers who were more likely to be taught about genetics in medical school and residency were better able to interpret the three testing scenarios.

Takeaway: “The significance of this study is that it’s the first time we’ve looked at how health professionals and genetic specialists interpret this data, not just the consumer,” according to McGrath. The good news is that it suggests that when specialists are unavailable, primary care providers are prepared to take on the task of interpreting genetic data, despite their lack of specialized training and experience. However, the study also shows that having such training and experience significantly enhances their ability to interpret those results correctly.