Of the 4,821 unique studies that were identified through database searching, 323 articles were assessed for full-text eligibility. Twenty-nine articles (Shaw III and Bassi, 2001; Laskey S.L. et al., 2003; Sanderson et al., 2004, 2017; Allen K.J. et al., 2008; Borry et al., 2008; Neghina A.M. and Anghel A., 2010; Haga et al., 2011; Hardie, 2011; Henneman L. et al., 2011; Nielsen and El-Sohemy, 2012; Nusbaum R. et al., 2013; Haga S.B. et al., 2014; Vassy J.L. et al., 2014; Hietaranta-Luoma H.-L. et al., 2015; O’Neill S.C. et al., 2015; Shiloh S. et al., 2015; Godino J.G. et al., 2016; Nicholls S.G. et al., 2016; Sanderson S.C. et al., 2016; Vassy et al., 2017; Fenton G.L. et al., 2018; Hay J.L. et al., 2018; East et al., 2019; Rego S. et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019; Joshi E. et al., 2020; Smit et al., 2020) were included in our analysis after assessing the articles according to the inclusion and exclusion criteria, and their characteristics are available in Table 1 (see Figure 1 for PRISMA diagram).
Six studies investigated the perspective of patients (Allen K.J. et al., 2008; Neghina A.M. and Anghel A., 2010; Nusbaum R. et al., 2013; Hietaranta-Luoma H.-L. et al., 2015; East et al., 2019; Rubinsak et al., 2019), four investigated the perspective of providers (Borry et al., 2008; Haga et al., 2011; Vassy J.L. et al., 2014; Joshi E. et al., 2020), one study investigated the perspectives of both patients and providers (Vassy et al., 2017), and eighteen studies investigated the perspective of the public (Shaw III and Bassi, 2001; Laskey S.L. et al., 2003; Sanderson et al., 2004, 2017; Hardie, 2011; Henneman L. et al., 2011; Nielsen and El-Sohemy, 2012; Haga S.B. et al., 2014; O’Neill S.C. et al., 2015; Shiloh S. et al., 2015; Godino J.G. et al., 2016; Nicholls S.G. et al., 2016; Sanderson S.C. et al., 2016; Fenton G.L. et al., 2018; Hay J.L. et al., 2018; Rego S. et al., 2019; Zoltick E.S. et al., 2019; Smit et al., 2020). Ten studies did not record race or ethnicity information (Allen K.J. et al., 2008; Borry et al., 2008; Neghina A.M. and Anghel A., 2010; Hardie, 2011; Hietaranta-Luoma H.-L. et al., 2015; Godino J.G. et al., 2016; Fenton G.L. et al., 2018; East et al., 2019; Joshi E. et al., 2020; Smit et al., 2020). Two studies were conducted solely with female participants (Henneman L. et al., 2011; Rubinsak et al., 2019) and one did not record information about gender (Joshi E. et al., 2020). Seven studies did not record the mean age of participants (Laskey S.L. et al., 2003; Borry et al., 2008; Haga et al., 2011; Haga S.B. et al., 2014; Fenton G.L. et al., 2018; Rego S. et al., 2019; Joshi E. et al., 2020).
Eighteen studies implemented population screening programs of some kind (Allen K.J. et al., 2008; Neghina A.M. and Anghel A., 2010; Nielsen and El-Sohemy, 2012; Nusbaum R. et al., 2013; Haga S.B. et al., 2014; Hietaranta-Luoma H.-L. et al., 2015; O’Neill S.C. et al., 2015; Shiloh S. et al., 2015; Godino J.G. et al., 2016; Sanderson S.C. et al., 2016; Sanderson et al., 2017; Vassy et al., 2017; Fenton G.L. et al., 2018; Hay J.L. et al., 2018; East et al., 2019; Rego S. et al., 2019; Zoltick E.S. et al., 2019; Smit et al., 2020) and the remaining eleven investigated individuals’ opinions on population genetic screening (Shaw III and Bassi, 2001; Laskey S.L. et al., 2003; Sanderson et al., 2004; Borry et al., 2008; Haga et al., 2011; Hardie, 2011; Henneman L. et al., 2011; Vassy J.L. et al., 2014; Nicholls S.G. et al., 2016; Rubinsak et al., 2019; Joshi E. et al., 2020). Of those that implemented screening programs, five provided counseling before screening (Neghina A.M. and Anghel A., 2010; Sanderson S.C. et al., 2016; Sanderson et al., 2017; East et al., 2019; Smit et al., 2020), four provided counseling after screening (Allen K.J. et al., 2008; Haga S.B. et al., 2014; Shiloh S. et al., 2015; Rego S. et al., 2019), five provided counseling at both timepoints (Nusbaum R. et al., 2013; Hietaranta-Luoma H.-L. et al., 2015; Vassy et al., 2017; Fenton G.L. et al., 2018; Zoltick E.S. et al., 2019), and four did not record counseling availability (Nielsen and El-Sohemy, 2012; O’Neill S.C. et al., 2015; Godino J.G. et al., 2016; Hay J.L. et al., 2018).
The majority of studies (n=16) were conducted in the US (Shaw III and Bassi, 2001; Laskey S.L. et al., 2003; Haga et al., 2011; Nusbaum R. et al., 2013; Haga S.B. et al., 2014; Vassy J.L. et al., 2014; O’Neill S.C. et al., 2015; Shiloh S. et al., 2015; Sanderson S.C. et al., 2016; Sanderson et al., 2017; Vassy et al., 2017; Hay J.L. et al., 2018; East et al., 2019; Rego S. et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019), while the rest were conducted in Europe (UK (Sanderson et al., 2004; Godino J.G. et al., 2016), The Netherlands (Henneman L. et al., 2011), Romania (Neghina A.M. and Anghel A., 2010), Finland (Hietaranta-Luoma H.-L. et al., 2015), European Union (Borry et al., 2008)), Canada (Nielsen and El-Sohemy, 2012; Nicholls S.G. et al., 2016; Joshi E. et al., 2020), and Australia (Allen K.J. et al., 2008; Hardie, 2011; Fenton G.L. et al., 2018; Smit et al., 2020). Sixteen studies were conducted in a clinical setting (Neghina A.M. and Anghel A., 2010; Haga et al., 2011; Nusbaum R. et al., 2013; Haga S.B. et al., 2014; Vassy J.L. et al., 2014; Hietaranta-Luoma H.-L. et al., 2015; Shiloh S. et al., 2015; Sanderson S.C. et al., 2016; Sanderson et al., 2017; Vassy et al., 2017; Hay J.L. et al., 2018; East et al., 2019; Rego S. et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019; Joshi E. et al., 2020), nine were conducted in a community setting (Shaw III and Bassi, 2001; Sanderson et al., 2004; Allen K.J. et al., 2008; Henneman L. et al., 2011; Nielsen and El-Sohemy, 2012; Godino J.G. et al., 2016; Nicholls S.G. et al., 2016; Fenton G.L. et al., 2018; Smit et al., 2020), and four did not report the setting type (Laskey S.L. et al., 2003; Borry et al., 2008; Hardie, 2011; O’Neill S.C. et al., 2015). One study was conducted on an international scale (Borry et al., 2008), ten were conducted nationally (Sanderson et al., 2004; Haga et al., 2011; Hardie, 2011; Nielsen and El-Sohemy, 2012; O’Neill S.C. et al., 2015; Shiloh S. et al., 2015; Godino J.G. et al., 2016; Nicholls S.G. et al., 2016; Zoltick E.S. et al., 2019; Joshi E. et al., 2020), three on a state scale (Fenton G.L. et al., 2018; Hay J.L. et al., 2018; Smit et al., 2020), two regionally (Hietaranta-Luoma H.-L. et al., 2015), five in a city/town (Shaw III and Bassi, 2001; Allen K.J. et al., 2008; Henneman L. et al., 2011; Vassy J.L. et al., 2014; Vassy et al., 2017), and nine at a single center (Laskey S.L. et al., 2003; Neghina A.M. and Anghel A., 2010; Nusbaum R. et al., 2013; Haga S.B. et al., 2014; Sanderson S.C. et al., 2016; Sanderson et al., 2017; East et al., 2019; Rego S. et al., 2019; Rubinsak et al., 2019).
Ten articles conducted descriptive studies using survey and questionnaire data (Shaw III and Bassi, 2001; Laskey S.L. et al., 2003; Sanderson et al., 2004; Allen K.J. et al., 2008; Borry et al., 2008; Neghina A.M. and Anghel A., 2010; Haga et al., 2011; East et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019), six conducted qualitative studies using interview and focus group data (Henneman L. et al., 2011; Nusbaum R. et al., 2013; O’Neill S.C. et al., 2015; Rego S. et al., 2019; Joshi E. et al., 2020; Smit et al., 2020), six conducted mixed-method studies (Hardie, 2011; Vassy J.L. et al., 2014; Nicholls S.G. et al., 2016; Sanderson S.C. et al., 2016; Sanderson et al., 2017; Fenton G.L. et al., 2018), six conducted randomized controlled trials (Nielsen and El-Sohemy, 2012; Haga S.B. et al., 2014; Hietaranta-Luoma H.-L. et al., 2015; Godino J.G. et al., 2016; Vassy et al., 2017; Hay J.L. et al., 2018), and one conducted non-randomized controlled trials (Shiloh S. et al., 2015).
3.1.1.1 Intrapersonal Barriers
Psychosocial Factors, Knowledge, Attitudes, and Beliefs
Psychosocial factors such as anxiety, fear, and worry about screening (Hardie, 2011; Nusbaum R. et al., 2013; Rubinsak et al., 2019), dislike of blood (Neghina A.M. and Anghel A., 2010), potential negative psychological and emotional impacts (Henneman L. et al., 2011; Sanderson S.C. et al., 2016; Joshi E. et al., 2020), mistrust (Hardie, 2011), disinterest (Neghina A.M. and Anghel A., 2010; Hardie, 2011), the possibility of receiving unwanted information (Zoltick E.S. et al., 2019), and the belief that a low-risk result may not give reassurance (Henneman L. et al., 2011) were reported as reasons to reject screening. Two studies reported moral and ethical reasons as barriers (Shaw III and Bassi, 2001; Hardie, 2011). Providers cited inadequate knowledge (Haga et al., 2011; Joshi E. et al., 2020), not having ordered a genetic test for themselves (Haga et al., 2011), their belief that it would not provide useful information (Haga et al., 2011), and their belief that it would lead to unnecessary future testing (Vassy J.L. et al., 2014) as barriers to participating in population genetic screening programs. Additionally, patients reported a lack of information (Neghina A.M. and Anghel A., 2010; Nusbaum R. et al., 2013; Rubinsak et al., 2019) a barrier.
Clinical Factors
Providers (Vassy J.L. et al., 2014; Joshi E. et al., 2020) and the public (Zoltick E.S. et al., 2019) cited the uncertainty of results as a barrier. Providers additionally reported limited clinical utility as a barrier (Borry et al., 2008; Vassy J.L. et al., 2014; Joshi E. et al., 2020).
Other
Perceived cost of genetic screening (Hardie, 2011; Rubinsak et al., 2019; Zoltick E.S. et al., 2019), religious reasons (Hardie, 2011), and higher education (Sanderson et al., 2004) were reported as barriers. Patients additionally reported a lack of time as a barrier to receipt of genetic screening (Neghina A.M. and Anghel A., 2010).
3.1.1.2 Interpersonal Barriers
Family
A perceived potential for a negative impact on children (Sanderson S.C. et al., 2016) and a lack of family history (Hardie, 2011; Rubinsak et al., 2019) were negatively correlated with interest and/or receipt of genetic screening.
3.1.1.3 Community Barriers
Data
Concerns related to confidentiality and privacy (Haga et al., 2011; Nusbaum R. et al., 2013; Sanderson S.C. et al., 2016; Zoltick E.S. et al., 2019) and data security (Joshi E. et al., 2020) were reported as barriers.
Healthcare System
Providers and the public reported that the potential impact of results on insurance (Haga et al., 2011; Henneman L. et al., 2011; Zoltick E.S. et al., 2019; Joshi E. et al., 2020) and the potential increased cost to the health system (Henneman L. et al., 2011; Joshi E. et al., 2020; Smit et al., 2020) would hinder their participation of genetic screening at a population level.
Other
The possibility for discrimination by employers was reported by providers and the public as a barrier (Henneman L. et al., 2011; Joshi E. et al., 2020).
3.1.1.4 Intrapersonal Facilitators
Demographics and Socio-Economic Status
One study (Sanderson et al., 2004) reported that male gender (p = 0.029) and later middle age were positively correlated with interest in screening. On the other hand, another study (Neghina A.M. and Anghel A., 2010) reported that younger age was a facilitator to uptake of screening. Higher socioeconomic status was additionally cited as a facilitator (Neghina A.M. and Anghel A., 2010; Hay J.L. et al., 2018).
Psychosocial Factors, Knowledge, Attitudes, and Beliefs
Interest-related facilitators include interest about ancestry (Sanderson S.C. et al., 2016; Zoltick E.S. et al., 2019), professional interest (Sanderson S.C. et al., 2016; Zoltick E.S. et al., 2019), interest in genetics and/or science (Sanderson S.C. et al., 2016; Rego S. et al., 2019; Zoltick E.S. et al., 2019), and general curiosity (Hardie, 2011; Nusbaum R. et al., 2013; Sanderson S.C. et al., 2016; East et al., 2019; Zoltick E.S. et al., 2019). Altruism (Nusbaum R. et al., 2013; Sanderson S.C. et al., 2016; Rego S. et al., 2019) and the chance for participants to learn about themselves (Nielsen and El-Sohemy, 2012; Sanderson S.C. et al., 2016; Rubinsak et al., 2019) were reported as facilitators as well. Trust in provider (Hardie, 2011) and trust in medicine (Hardie, 2011) were both significantly correlated with interest in population screening. Additional facilitators include knowledge (Borry et al., 2008; Haga et al., 2011) and the belief that screening will provide helpful information (Shaw III and Bassi, 2001).
Clinical Factors
All stakeholders viewed the potential for medical intervention and/or monitoring (Borry et al., 2008; Nielsen and El-Sohemy, 2012; Sanderson S.C. et al., 2016; East et al., 2019; Joshi E. et al., 2020) as a facilitator to population genetic screening. The public reported that curability (p < 0.001) (Shaw III and Bassi, 2001), non-fatalness of a condition (p < 0.01) (Shaw III and Bassi, 2001), a more certain outcome (Shaw III and Bassi, 2001), a known or suspected personal history (Sanderson S.C. et al., 2016; Hay J.L. et al., 2018), the potential to encourage health improvements through means such as behavioral changes (Hardie, 2011; Nielsen and El-Sohemy, 2012; Sanderson S.C. et al., 2016; Zoltick E.S. et al., 2019), and the use of results for future diagnostic purposes (Sanderson S.C. et al., 2016) were positively associated with interest and/or receipt of genetic screening through a population-based context. Additionally, patients reported their seeking medical information as a reason for receiving screening (Neghina A.M. and Anghel A., 2010; Nusbaum R. et al., 2013; East et al., 2019). Patients and the public reported that the ability to prepare for future health (Nicholls S.G. et al., 2016; Sanderson S.C. et al., 2016; East et al., 2019; Rego S. et al., 2019; Zoltick E.S. et al., 2019) and the use of results for pharmacogenomics (Sanderson S.C. et al., 2016; East et al., 2019; Zoltick E.S. et al., 2019) were facilitators to genetic screening.
Other
Patients reported that the chance to have a free screen (Neghina A.M. and Anghel A., 2010) and a ‘nothing to lose’ attitude (Nusbaum R. et al., 2013) were facilitators for their receipt of genetic screening. Viewing genetic screening as a novel opportunity (Sanderson S.C. et al., 2016) and a fun and entertaining activity (Zoltick E.S. et al., 2019) was reported by the public as a facilitator for undergoing screening.
3.1.1.5 Interpersonal Facilitators
Family
All interpersonal facilitators were related to participants’ family. Seven studies reported that the ability to provide information to family members was important to participants (Nusbaum R. et al., 2013; Nicholls S.G. et al., 2016; Sanderson S.C. et al., 2016; East et al., 2019; Rego S. et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019). One study reported that having family who have had their genomes sequenced facilitated uptake (Zoltick E.S. et al., 2019). Family history was reported in six studies (Hardie, 2011; Sanderson S.C. et al., 2016; Hay J.L. et al., 2018; Rego S. et al., 2019; Rubinsak et al., 2019; Zoltick E.S. et al., 2019) and labeled as a statistically significant factor in one (Sanderson et al., 2004). On the other hand, a lack of family health history was also reported as a facilitator in four studies (Sanderson et al., 2004; Sanderson S.C. et al., 2016; Rego S. et al., 2019; Zoltick E.S. et al., 2019).