Geographical Access, Implementation Experience, and Patient Perception of Genetic Testing in the United States
Type of DegreePhD Dissertation
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Backgrounds: Genetic testing is thriving, and its impact on human lives is enormous. However, the slow uptake of genetic testing into routine clinical practice indicates that much remains to be explored with regards to finding the best ways to facilitate the implementation process. Objective and Specific Aims: The purpose of this study is to conduct a comprehensive analysis regarding access to genetic testing centers, implementation issues, and public awareness, perceptions, and preferences towards genetic testing concepts and strategies involving large minority groups as well as rural populations. This study used a road network analysis, a scoping review, and a Qualtrics survey to address three specific aims: 1) to examine the geographical access to genetic testing centers for people living in the United States, 2) to synthesize current evidence on the barriers and facilitators to implementation of pharmacogenetic testing in a healthcare setting, and 3) to assess the awareness, perceptions, and preferences toward genetic testing among the United States general public, and how this may vary by racial-ethnic group and rural-urban status. Methods: For aim 1, genetic testing center addresses were collected from the American College of Medical Genetics and Genomics (ACMG) website and then geocoded the genetic testing center locations as destinations using ArcGIS address locator. The centroid points were calculated for each US census tracts and set them as origins. Then, a road network analysis of travel times was performed between origin and destination using closest network facility analysis feature in ArcGIS online ready-to-use services. A descriptive summary of the total US population by travel times categories i.e., less than 30 minutes, 30 to 59 minutes, 60 to 119 minutes, 120 to 179 minutes, and 180 minutes and above was presented. Chi-square tests were used to compare the differences between racial groups by travel time categories. For aim 2, a scoping review was conducted with an expanded literature search using Ovid MEDLINE, Web of Science, International Pharmaceutical Abstract (IPA), and Google Scholar to look for any studies reporting implementation of pharmacogenetic testing in a healthcare setting, from a health systems perspective. Articles were screened using the DistillerSR and findings were organized using the five major domains of Consolidated Framework for Implementation Research. For aim 3, we developed a survey questionnaire using Health Information National Trends Survey (HINTS) and Theory of Planned Behavior constructs. We used a Qualtrics panel to recruit a total of 1,600 members of the US general public to respond to our survey. Comparisons between different racial-ethnic groups and rural-urban respondents for awareness and preference sections were made using chi-square tests. For the perceptions domain, logistic regression models were used while dichotomizing the dependent variable “intention to get a genetic test” into low intention (less than median score) and high intention (median and above). Results: Findings from our road network analysis revealed that more than 3 million people in the United States, around 1% of the total population, had to drive 180 minutes or more to the nearest genetic testing center. In addition, 58% of Whites had to drive less than 30 mins to the nearest center, while significantly higher percentages of Blacks (73%) and Asians (82%) had similar distance to travel. One striking finding from our scoping review is that the majority of barriers and solutions to the implementation of pharmacogenetic testing in healthcare settings surrounded intervention characteristics and inner settings. Factors relating to cost and reimbursement were described as a major barrier in the intervention characteristics. Another two major barriers identified in our scoping review were the lack of utility studies to provide evidence for genetic testing uptake and technical issues such as integrating genetic information to medical records. Our findings suggest that long term program evaluations are required to verify the role of the discussed factors in the uptake of genetic testing across different healthcare settings using rigorous methods. Findings from our Qualtrics survey revealed that respondents were aware of genetic testing and understood its role around risk of disease and inheritance, but half of the total respondents were not aware of genetic testing in the context of choice of treatments, identifying adverse events, and dosage correction. Participants preferred to share their test results with doctors and genetic counselors over pharmacists. But they were not comfortable sharing the results with employers and health insurance providers. Statistically significant differences between different racial and ethnic groups as well as the rural-urban populations were observed across different survey questions. Conclusions: Overall, access to genetic testing clinics is still a hurdle for people living in some specific states as well as Whites compared to Blacks and Asians living in the US. Barriers and facilitators identified in this scoping review should act as a checklist for future implementation since the findings are comprehensive and reported based on an implementation framework. More educational resources and trainings are required for all different stakeholders including prescribers, pharmacists, and patients to increase genetic testing uptake among the general population in the US.