institute for health transformation
Joaquim Cardoso MSc
Chief Researcher, Editor & Senior Advisor
Decemberr 31, 2022
Executive Summary
What is the context?
- Studies suggest that 1–3% of the general population in the United States unknowingly carry a genetic risk factor for a common hereditary disease.
- Population genetic screening is the process of offering otherwise healthy patients in the general population testing for genomic variants that predispose them to diseases that are clinically actionable, meaning that they can be prevented or mitigated if they are detected early.
- Population genetic screening may significantly reduce morbidity and mortality from these diseases by informing risk-specific prevention or treatment strategies and facilitating appropriate participation in early detection.
What is the scope of the study?
- To better understand current barriers, facilitators, perceptions, and outcomes related to the implementation of population genetic screening, the authors conducted a systematic review and searched PubMed, Embase, and Scopus for articles published from date of database inception to May 2020
- The authors included articles that 1) detailed the perspectives of participants in population genetic screening programs and 2) described the barriers, facilitators, perceptions, and outcomes related to population genetic screening programs among patients, healthcare providers, and the public.
- The authors excluded articles that 1) focused on direct-to-consumer or risk-based genetic testing and 2) were published before January 2000.
- Thirty articles met these criteria.
- Barriers and facilitators to population genetic screening were organized by the Social Ecological Model and further categorized by themes.
What are the findings?
- The authors found that research in population genetic screening has focused on stakeholder attitudes with all included studies designed to elucidate individuals’ perceptions.
- Additionally, inadequate knowledge and perceived limited clinical utility presented a barrier for healthcare provider uptake.
- There were very few studies that conducted long-term follow-up and evaluation of population genetic screening.
What are the conclusions & recommendations?
- Our findings suggest that these and other factors, such as prescreen counseling and education, may play a role in the adoption and implementation of population genetic screening.
- Future studies to investigate macro-level determinants, strategies to increase provider buy-in and knowledge, delivery models for prescreen counseling, and long-term outcomes of population genetic screening are needed for the effective design and implementation of such programs.
ORIGINAL PUBLICATION
Barriers and Facilitators for Population Genetic Screening in Healthy Populations: A Systematic Review
Frontiers IN
Emily C. Shen1,2 , Swetha Srinivasan3 , Lauren E. Passero3 , Caitlin G. Allen4 , Madison Dixon5 , Kimberly Foss 6 , Brianna Halliburton1 , Laura V. Milko6 , Amelia K. Smit 7,8 , Rebecca Carlson9 and Megan C. Roberts 3 *
04 July 2022
1 Introduction
Studies suggest that 1–3% of the general population in the United States carry a genetic risk factor for a common hereditary disease.
Typically, genetic testing approaches for identifying these individuals are limited to testing those at high risk of hereditary disease (e.g., cascade testing for at-risk relatives of individuals with a diagnosis).
Conversely, population genetic screening offers genetic testing (for common genomic variants) to otherwise healthy individuals to inform risk assessment, precision prevention and early detection of preventable, common diseases.
A key example of population genetic screening is newborn screening, which is often celebrated as one of public health’s best accomplishments ( Murray et al., 2018).
A key example of population genetic screening is newborn screening, which is often celebrated as one of public health’s best accomplishments
The Centers for Disease Control and Prevention Office of Genomics and Precision Health has prioritized population genetic screening for common disease conditions (Hereditary Breast and Ovarian Cancer, Lynch Syndrome, and familial hypercholesterolemia) as Tier 1 applications for genomics due to their “significant potential for positive impact on public health” ( CDC, 2021).
The Centers for Disease Control and Prevention Office of Genomics and Precision Health has prioritized population genetic screening for common disease conditions …
While clinical evidence is currently insufficient to recommend widespread screening in healthy populations ( Hampel and de la Chapelle, 2011; Representatives of the Global Familial Hypercholesterolemia Community, 2020), clinical pilot programs are in place to understand cost-efficiency, implementation, and other health related outcomes of population genetic screening ( Hay et al., 2021; Lacson et al., 2021; Smit et al., 2021).
While clinical evidence is currently insufficient to recommend widespread screening in healthy populations …clinical pilot programs are in place to understand cost-efficiency, implementation, and other health related outcomes of population genetic screening …
These pilot studies are on the rise and offer promising opportunities to build the necessary knowledge base for expanding population genetic screening.
Understanding the barriers, facilitators, perceptions, and outcomes to population genetic screening of healthy populations is critical for implementing screening programs in healthcare settings.
Previous systematic reviews relating to population genetic screening focus on economic and informed choice evaluations ( Rogowski, 2006; Ames et al., 2015).
To address this need, we conducted a systematic review of current research literature to understand the barriers, facilitators, perceptions, and outcomes that will be vital for the successful translation of research to support population genetic screening (if found to be appropriate for scaling up).
2 Method, Results & Other sections
See the original publication
4 Discussion
Overall, we identified multilevel barriers and facilitators for population genetic screening implementation.
Psychosocial and attitudinal barriers, such as anxiety and worry toward screening and the possibility for negative psychological and emotional impacts, were the most reported individual-level barriers across stakeholders, even though studies to date have demonstrated limited impacts on psychological and emotional outcomes with any adverse responses dissipating over time ( Hietaranta-Luoma et al., 2015; Hollands et al., 2016; Frieser et al., 2018; Smit et al., 2020).
Many of our included studies investigated the general public’s perspective of population genetic screening.
This presents an opportunity to focus on the roles of other stakeholders within the larger societal systems, such as healthcare providers and public health officials. Primary care providers, who will likely be the touchpoint for many interested in population genetic screening, reported inadequate knowledge as a barrier to ordering screening. In one study ( Haga et al., 2011), roughly half of providers reported that they felt prepared to order population genetic screening. Previous literature has noted the limited evidence regarding the views and roles of healthcare providers in genomic medicine ( Hann et al., 2017a; Hauser et al., 2018; Crellin et al., 2019), identified the importance of educational resources for provider preparedness to order and interpret results ( Rohrer Vitek et al., 2017; Hauser et al., 2018; Smit et al., 2019), and described the integral role that public health officials will play in insuring proper implementation of population genetic screening ( Molster et al., 2018). With few provider-based studies (most of which studied primary care providers) and no public health-based studies, we see a need for increased studies to investigate the viewpoints of these providers and develop the necessary educational interventions.
Furthermore, the current state of research in population genetic screening focuses on individuals, with most studies revealing barriers and facilitators to interest and/or participation in population genetic screening at an individual level.
We identified few interpersonal facilitators and barriers and no community-level facilitators. All our included studies were designed to elucidate stakeholders’ views and attitudes. This leaves a large gap in the literature in understanding the complex interactions between communities, the healthcare system, and the public health system. The studies which revealed interpersonal and community factors conducted surveys or semi-structured interviews, suggesting a need for additional studies to explicitly investigate macro-level determinants for population genetic screening that are suited to quantitative methods.
Most (all but two) were conducted in racially/ethnically diverse countries (Australia, Canada, United States, and United Kingdom), however roughly one third did not include information on the race or ethnicity of individuals receiving population genetic screening.
This is of particular importance as studies have found ethnic minorities to be generally more apprehensive toward genetic testing than white individuals ( Hann et al., 2017b). Without data on race and ethnicity of study populations the generalizability of findings is unclear and we remain unable to monitor disparities in access to population genetic screening. This suggests a need for improved reporting of race/ethnicity in population genetic screening research and a need to focus on health equity.
In addition to this challenge, more general agreement on the terminology and reporting of race, ethnicity, and ancestry in genomic research with an eye toward reproducible, ethical, and equitable research is warranted ( Flanagin et al., 2021).
the National Human Genome Research Institute (NHGRI) boldly predicts that “research in human genomics will have moved beyond population descriptors based on historic social constructs such as race” by 2030 ( Green et al., 2020), there are currently numerous challenges inherent in standardizing the use (or disuse) of race and ethnicity and other population descriptors in clinical genetics. Fortunately, the National Academies of Sciences, Engineering, and Medicine established a multi-disciplinary committee to examine the current use of population descriptors in genomics research and identify best practices for improving the use of the terminology in the future.
Many studies incorporated genetic counseling; however, they had varying forms of preintervention information content and delivery and only a few assessed the efficacy of different delivery methods.
The best approach and timing for genetic counseling delivery has not yet been determined. To date, there is some evidence showing that different contexts will likely have different requirements ( Evans and Manchanda, 2020). For example, while this review explicitly excluded reproductive genetic testing, population-wide screening will nonetheless have profound implications for individuals of reproductive age who would be at risk of passing a hereditary predisposition for a life-threatening condition to existing or future children. This provides an opportunity to implement studies specifically designed to investigate the best manner of prescreen education and counseling specific to the delivery context, such as health literacy levels, cultural considerations, reproductive age, and disease type.
Finally, out of the studies that implemented population genetic screening and collected post-intervention data, only one followed participants for more than 12 months ( Allen et al., 2008).
Without sufficient long-term data, it is difficult to assess the efficacy of the screening programs at the population level. There is a need for prospective cohort studies and randomized controlled trials to evaluate any long-term benefits, such as clinical and economic outcomes, to population-level genetic screening implementation ( Murray et al., 2018, 2020). The BabySeq project provides a model for identifying these long-term outcomes ( Holm et al., 2018), which may be adapted to the context of population genetic screening. Such studies will likely address our previous points of determining ELSI factors to population genetic screening and assessing the effects of prescreen education methods as well.
5 Limitations
There is a potential for bias as we reported missing items as “not reported” and did not contact authors for additional information.
Articles varied as to which outcome was reported (barrier, facilitator, perception, and/or outcome), so some articles may be more represented than others.
Our included studies did not assess effect sizes of barriers and facilitators on interest and/or uptake of population genetic screening, which prevented us from conducting a meta-analysis.
Additionally, the heterogeneity in disease states and reported effectiveness measures prevented us from fully synthesizing the data.
With all systematic reviews, there is the possibility that we missed relevant literature.
6 Conclusion
We found that
- 1) psychosocial, attitudinal, and belief-related factors present a barrier for stakeholders to participate in screening,
- 2) perceived limited clinical utility presents a barrier for provider uptake,
- 3) there is a need for additional studies investigating healthcare and public health provider roles and education,
- 4) research in population genetic screening has focused on stakeholder attitudes, and
- 5) there is a need for long-term follow-up studies and health equity-focused studies of population genetic screening.
Future research should
- 1) evaluate the best manner for prescreen education and counseling for specific contexts,
- 2) examine provider buy-in and clinical utility expansion,
- 3) investigate the views of providers and develop educational resources,
- 4) investigate macro-level determinants of and address ELSI questions toward population genetic screening, and
- 5) assess the long-term outcomes of population genetic screening.
Taken together this data can inform future interventions to improve the development and implementation of population genetic screening.
Funding
CA was supported by KooCA253576 through the Medical University of South Carolina. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
References
See original publication
Originally published at http://www.frontiersin.org.
About the authors & affiliations
Emily C. Shen1,2 ,
Swetha Srinivasan3 ,
Lauren E. Passero3 ,
Caitlin G. Allen4 ,
Madison Dixon5 ,
Kimberly Foss 6 ,
Brianna Halliburton1 ,
Laura V. Milko6 ,
Amelia K. Smit 7,8 ,
Rebecca Carlson9 and
Megan C. Roberts 3 *
1 College of Arts and Sciences,
University of North Carolina at Chapel Hill, Chapel Hill, NC, United States,
2 UNC Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina, Chapel Hill, NC, United States,
3 Division of Pharmaceutical Outcomes and Policy, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, United States,
4 Department of Public Health Science, College of Medicine,
Medical University of South Carolina, Charleston, SC, United States,
5 Department of Behavioral, Social, and Health Education Science,
Rollins School of Public Health,
Emory University, Atlanta, GA, United States,
6 Department of Genetics, School of Medicine, University of North Carolina, Chapel Hill, NC, United States,
7 The Daffodil Centre, University of Sydney, A Joint Venture with Cancer Council NSW, Sydney, NSW, Australia,
8 Melanoma Institute Australia,
University of Sydney, Sydney, NSW, Australia,
9 Health Sciences Library,
University of North Carolina, Chapel Hill, NC, United States
