Internet-Based Direct-to-Consumer Genetic Testing: A Systematic Review

Abstract

BackgroundDirect-to-consumer genetic tests (DTC-GT) are easily purchased through the Internet, independent of a physician referral or approval for testing, allowing the retrieval of genetic information outside the clinical context. There is a broad debate about the testing validity, their impact on individuals, and what people know and perceive about them.ObjectiveThe aim of this review was to collect evidence on DTC-GT from a comprehensive perspective that unravels the complexity of the phenomenon.MethodsA systematic search was carried out through PubMed, Web of Knowledge, and Embase, in addition to Google Scholar according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist with the key term “Direct-to-consumer genetic test.”ResultsIn the final sample, 118 articles were identified. Articles were summarized in five categories according to their focus on (1) knowledge of, attitude toward use of, and perception of DTC-GT (n=37), (2) the impact of genetic risk information on users (n=37), (3) the opinion of health professionals (n=20), (4) the content of websites selling DTC-GT (n=16), and (5) the scientific evidence and clinical utility of the tests (n=14). Most of the articles analyzed the attitude, knowledge, and perception of DTC-GT, highlighting an interest in using DTC-GT, along with the need for a health care professional to help interpret the results. The articles investigating the content analysis of the websites selling these tests are in agreement that the information provided by the companies about genetic testing is not completely comprehensive for the consumer. Given that risk information can modify consumers’ health behavior, there are surprisingly few studies carried out on actual consumers and they do not confirm the overall concerns on the possible impact of DTC-GT. Data from studies that investigate the quality of the tests offered confirm that they are not informative, have little predictive power, and do not measure genetic risk appropriately.ConclusionsThe impact of DTC-GT on consumers’ health perceptions and behaviors is an emerging concern. However, negative effects on consumers or health benefits have yet to be observed. Nevertheless, since the online market of DTC-GT is expected to grow, it is important to remain aware of a possible impact.

What Is the Psychosocial Impact of Providing Genetic and Genomic Health Information to Individuals? An Overview of Systematic Reviews

“…The reviews summarized below were picked to represent a range of types of genetic and genomic testing, each of which could generate a distinct psychosocial response among recipients. The topics include the psychosocial impact of Huntington disease testing, the decision to decline testing, testing for hereditary cancers, testing of symptomatic individuals, carrier testing, direct‐to‐consumer testing, pediatric testing, and familial communication of risks . After presenting these examples, I will synthesize the systematic review findings, discuss the quality of the source literature, and summarize overarching gaps and recommendations identified by the reviews.…”

“…A systematic review by Loredana Covolo et al aimed to clarify the impacts of DTC genetic and genomic testing, partly by describing how recipients respond to learning about their risks . The review identified thirty‐seven studies addressing the impact of DTC testing on consumers, but the focus here will be on the nine research studies that explored the perspectives of individuals who actually received test results.…”

“…Finally, the findings of systematic reviews are pertinent only to the extent that the aggregated original research is of high quality. Several of the discussed reviews did not offer a formal assessment of the methodological quality of source material, but the four reviews that applied a systematized evaluation found the quality of the literature base to be adequate . Nonetheless, most reviews did mention potential methodological problems in the literature that are worth noting as one considers the results obtained and future directions.…”

“…This diversity of approaches put limitations on reviewers’ ability to draw conclusions across studies. Additionally, some reviews noted the potential for bias due to factors like low survey response rates, attrition, underpowered samples, sample selection procedures, and homogeneous samples that overrepresented white and highly educated participants . Together, these shared limitations suggest opportunities for improving the quality of the evidence base for psychosocial impacts of genetic and genomic testing.…”

Genetics in the 21st Century: Implications for patients, consumers and citizens

“…Proponents argue that they empower consumers to take responsibility for their health 24 and improve the quality of their life 25 . However, researchers and health professionals have raised concerns about the clinical validity of DTC genetic tests, particularly in relation to susceptibility testing for complex disease, such as diabetes or dementia 26, 27 . Specifically, researchers have argued that these tests fail to take into account non-genetic factors that can contribute to complex disease 24 .…”