Healthcare Utilization and Patients' Perspectives After Receiving a Positive Genetic Test for Familial Hypercholesterolemia

Systematic review of the uptake and outcomes from returning secondary findings to adult participants in research genomic testing

The increasing use of genomic sequencing in research means secondary findings (SF) is more frequently detected and becoming a more pressing issue for researchers. This is reflected by the recent publication of multiple guidelines on this issue, calling for researchers to have a plan for managing SF prior to commencing their research. A deeper understanding of participants' experiences and outcomes from receiving SF is needed to ensure that the return of SF is conducted ethically and with adequate support. This review focuses on the uptake and outcomes of receiving actionable SF for research participants. This review included studies from January 2010 to January 2023. Databases searched included Medline, Embase, PsycINFO, and Scopus. Of the 3903 studies identified, 29 were included in the analysis. The uptake of SF ranged between 20% and 97%, and outcomes were categorized into psychological, clinical, lifestyle and behavioral, and family outcomes. The results indicate there is minimal psychological impact from receiving SF. Almost all participants greatly valued receiving SF. These findings highlight considerations for researchers when returning results, including the importance of involving genetic health professionals in consenting, results return process, and ensuring continuity of care by engaging healthcare providers.

Development and Pilot Testing of Evidence-Based Interventions to Improve Adherence after Receiving a Genetic Result

INTRODUCTION

Previous research indicates that population genomic screening can benefit individuals who act on the genetic results. However, there remains a significant gap between individuals receiving genetic information and acting on current risk management recommendations, prompting exploration of interventions to close this gap. This study aimed to determine the feasibility and acceptability and conduct a pilot implementation of existing evidence-based interventions (EBIs) for adherence to disease management for select genetic conditions among individuals ascertained through a population genomic screening program.

METHODS

Surveys of and interviews with individuals who received a genomic screening result were conducted to assess barriers to guideline-recommended care and assess the acceptability of problem-solving (PS) and motivational interviewing (MI) EBIs to facilitate adherence to recommendations. A design thinking workshop was conducted with clinicians to co-develop an MI- and PS-based intervention that would fit with current workflows to be piloted. Post-pilot engagement sessions with implementers determined acceptability and feasibility of the MI/PS pilot program for clinical implementation and elicited proposed adaptations for improvement.

RESULTS

PS and MI EBIs were reported to be acceptable and feasible to individuals with a result, and barriers to performing recommended management were identified. The pilot program included outreach by genetic counselors to individuals with a result, review of a checklist of barriers, and delivery of PS or MI as appropriate to facilitate care. The protocol as piloted was deemed acceptable and feasible for clinicians to deliver, with adaptations suggested.

CONCLUSION

These results will inform an effectiveness trial to address gaps in adherence in patients who have received actionable genomic results.

Design and pilot results from the Million Veteran Program Return Of Actionable Results (MVP-ROAR) Study

BACKGROUND

As a mega-biobank linked to a national healthcare system, the Million Veteran Program (MVP) can directly improve the health care of participants. To determine the feasibility and outcomes of returning medically actionable genetic results to MVP participants, the program launched the MVP Return of Actionable Results (MVP-ROAR) Study, with familial hypercholesterolemia (FH) as an exemplar actionable condition.

METHODS

The MVP-ROAR Study consists of a completed single-arm pilot phase and an ongoing randomized clinical trial (RCT), in which MVP participants are recontacted and invited to receive clinical confirmatory gene sequencing testing and a telegenetic counseling intervention. The primary outcome of the RCT is 6-month change in low-density lipoprotein cholesterol (LDL-C) between participants receiving results at baseline and those receiving results after 6 months.

RESULTS

The pilot developed processes to identify and recontact participants nationally with probable pathogenic variants in low-density lipoprotein receptor (LDLR) on the MVP genotype array, invite them to clinical confirmatory gene sequencing, and deliver a telegenetic counseling intervention. Among participants in the pilot phase, 8 (100%) had active statin prescriptions after 6 months. Results were shared with 16 first-degree family members. Six-month ΔLDL-C (low-density lipoprotein cholesterol) after the genetic counseling intervention was -37 mg/dL (95% CI: -12 to -61; P = .03). The ongoing RCT will determine between-arm differences in this primary outcome.

CONCLUSION

While underscoring the importance of clinical confirmation of research results, the pilot phase of the MVP-ROAR Study marks a turning point in MVP and demonstrates the feasibility of returning genetic results to participants and their providers. The ongoing RCT will contribute to understanding how such a program might improve patient health care and outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID NCT04178122.

Understanding the Patient Experience of Receiving Clinically Actionable Genetic Results from the MyCode Community Health Initiative, a Population-Based Genomic Screening Initiative

Understanding unselected individuals’ experiences receiving genetic results through population genomic screening is critical to advancing clinical utility and improving population health. We conducted qualitative interviews with individuals who received clinically actionable genetic results via the MyCode© Genomic Screening and Counseling program. We purposively sampled cohorts to seek diversity in result-related disease risk (e.g., cancer or cardiovascular) and in personal or family history of related diseases. Transcripts were analyzed using a two-step inductive coding process of broad thematic analysis followed by in-depth coding of each theme. Four thematic domains identified across all cohorts were examined: process assessment, psychosocial response, behavioral change due to the genetic result, and family communication. Coding of 63 interviews among 60 participants revealed that participants were satisfied with the results disclosure process, initially experienced a range of positive, neutral, and negative psychological reactions to results, adjusted positively to results over time, undertook clinically indicated actions in response to results, and communicated results with relatives to whom they felt emotionally close. Our findings of generally favorable responses to receiving clinically actionable genetic results via a genomic screening program may assuage fear of patient distress in such programs and guide additional biobanks, genomic screening programs, and research studies.

A RE-AIM Framework Analysis of DNA-Based Population Screening: Using Implementation Science to Translate Research Into Practice in a Healthcare System

Introduction: DNA-based population screening has been proposed as a public health solution to identify individuals at risk for serious health conditions who otherwise may not present for medical care. The clinical utility and public health impact of DNA-based population screening is a subject of active investigation. Geisinger, an integrated healthcare delivery system, was one of the first healthcare systems to implement DNA screening programs (MyCode Community Health Initiative (MyCode) and clinical DNA screening pilot) that leverage exome data to identify individuals at risk for developing conditions with potential clinical actionability. Here, we demonstrate the use of an implementation science framework, RE-AIM (Reach, Effectiveness, Adoption, Implementation and Maintenance), to conduct a post-hoc evaluation and report outcomes from these two programs to inform the potential impact of DNA-based population screening. Methods: Reach and Effectiveness outcomes were determined from the MyCode research program, while Adoption and Implementation outcomes were measured using the clinical DNA screening pilot. Reach was defined as the number of patients who were offered and consented to participate in MyCode. Effectiveness of DNA screening was measured by reviewing MyCode program publications and synthesizing findings from themes. Adoption was measured by the total number of DNA screening tests ordered by clinicians at the clinical pilot sites. Implementation was assessed by interviewing a subset of clinical pilot clinicians about the deployment of and recommended adaptations to the pilot that could inform future program dissemination. Results: Reach: As of August 2020, 68% (215,078/316,612) of individuals approached to participate in the MyCode program consented. Effectiveness: Published evidence reported from MyCode demonstrates that DNA screening identifies at-risk individuals more comprehensively than clinical ascertainment based on phenotypes or personal/family history. Adoption: From July 2018 to June 2021, a total of 1,026 clinical DNA screening tests were ordered by 60 clinicians across the three pilot clinic sites. Implementation: Interviews with 14 clinicians practicing at the pilot clinic sites revealed motivation to provide patients with DNA screening results and yielded future implementation strategies. Conclusion: The RE-AIM framework offers a pragmatic solution to organize, analyze, and report outcomes across differently resourced and designed precision health programs that include genomic sequencing and return of clinically actionable genomic information.

Motivating cascade testing for familial hypercholesterolemia: applying the extended parallel process model for clinician communication

Motivating at-risk relatives to undergo cascade testing for familial hypercholesterolemia (FH) is critical for diagnosis and lifesaving treatment. As credible sources of information, clinicians can assist in family communication about FH and motivate cascade testing uptake. However, there are no guidelines regarding how clinicians should effectively communicate with probands (the first person diagnosed in the family) and at-risk relatives. Individuals and families with FH can inform our understanding of the most effective communications to promote cascade testing. Guided by the extended parallel process model (EPPM), we analyzed the perspectives of individuals and families with FH for effective messaging clinicians can use to promote cascade testing uptake. We analyzed narrative data from interviews and surveys collected as part of a larger mixed-methods study. The EPPM was used to identify message features recommended by individuals and families with FH that focus on four key constructs (severity, susceptibility, response efficacy, self-efficacy) to promote cascade testing. Participants included 22 individuals from 11 dyadic interviews and 98 survey respondents. Participants described prioritizing multiple messages that address each EPPM construct to alert relatives about their risk. They illustrated strategies clinicians could use within each EPPM construct to communicate to at-risk relatives about the importance of pursuing diagnosis via cascade testing and subsequent treatment for high cholesterol due to FH. Findings provide guidance on effective messaging to motivate cascade testing uptake for FH and demonstrates how the EPPM may guide communication with at-risk relatives about genetic risk and motivate cascade testing broadly.

Association of the Interaction Between Familial Hypercholesterolemia Variants and Adherence to a Healthy Lifestyle With Risk of Coronary Artery Disease

IMPORTANCE

Familial hypercholesterolemia variants impair clearance of cholesterol from the circulation and increase risk of coronary artery disease (CAD). The extent to which adherence to a healthy lifestyle is associated with a lower risk of CAD in carriers and noncarriers of variants warrants further study.

OBJECTIVE

To assess the association of the interaction between familial hypercholesterolemia variants and adherence to a healthy lifestyle with risk of CAD.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used 2 independent data sets with gene sequencing and lifestyle data from the UK Biobank: a case-control study of 4896 cases and 5279 controls and a cohort study of 39 920 participants. Participants were recruited from 22 sites across the UK between March 21, 2006, and October 1, 2010. The case-control study included participants with CAD and controls at enrollment. The cohort study used a convenience sample of individuals with available gene sequencing data. Statistical analysis was performed from April 2, 2019, to January 20, 2022.

EXPOSURES

Pathogenic or likely pathogenic DNA variants classified by a clinical laboratory geneticist and adherence to a healthy lifestyle based on a 4-point scoring system (1 point for each of the following: healthy diet, regular exercise, not smoking, and absence of obesity).

MAIN OUTCOMES AND MEASURES

Coronary artery disease, defined as myocardial infarction in the case-control study, and myocardial infarction, ischemic heart disease, or coronary revascularization procedure in the cohort study.

RESULTS

The case-control study included 10 175 participants (6828 men [67.1%]; mean [SD] age, 58.6 [7.2] years), and the cohort study included 39 920 participants (18 802 men [47.1%]; mean [SD] age at the end of follow-up, 66.4 [8.0] years). A variant was identified in 35 of 4896 cases (0.7%) and 12 of 5279 controls (0.2%), corresponding to an odds ratio of 3.0 (95% CI, 1.6-5.9), and a variant was identified in 108 individuals (0.3%) in the cohort study, in which the hazard ratio for CAD was 3.8 (95% CI, 2.5-5.8). However, this risk appeared to vary according to lifestyle categories in both carriers and noncarriers of familial hypercholesterolemia variants, without a significant interaction between carrier status and lifestyle (odds ratio, 1.2 [95% CI, 0.6-2.5]; P = .62). Among carriers, a favorable lifestyle conferred 86% lower risk of CAD compared with an unfavorable lifestyle (hazard ratio, 0.14 [95% CI, 0.04-0.41]). The estimated risk of CAD by the age of 75 years varied according to lifestyle, ranging from 10.2% among noncarriers with a favorable lifestyle to 24.0% among noncarriers with an unfavorable lifestyle and ranging from 34.5% among carriers with a favorable lifestyle to 66.2% among carriers with an unfavorable lifestyle.

CONCLUSIONS AND RELEVANCE

This study suggests that, among carriers and noncarriers of a familial hypercholesterolemia variant, significant gradients in risk of CAD are noted according to adherence to a healthy lifestyle pattern. Similar to the general population, individuals who carry familial hypercholesterolemia variants are likely to benefit from lifestyle interventions to reduce their risk of CAD.

Integrating Patient-Reported Outcomes Into Clinical Genetic Testing for Familial Hypercholesterolemia

Patient-reported outcomes (PROs) and PRO measures (PROMs) are often used to help clinicians and researchers understand patients' personal concerns, feelings, experiences, and perspectives following the implementation of an intervention. Notably, PROs and PROMs can inform health systems, health policy, and payers on the utility of clinical genetic testing based on each patient's personal values, perspectives, and potential health behaviors subsequent to testing. In this topic synopsis, we discuss the underexplored role of and implications for PROs and PROMs following genetic testing for familial hypercholesterolemia (FH), an autosomal dominant genetic disorder of cholesterol metabolism that can lead to highly premature fatal and nonfatal myocardial infarction and stroke. We also discuss why the use and consideration of patient perspectives, via PROs and PROMs, are critical to the process of optimizing patient care across various FH treatment contexts. As expert clinician groups consider the latest evidence when establishing recommendations for FH genetic testing, there is a ripe opportunity for clinicians and researchers to explore the value and utility of PROs to inform and possibly improve care for patients diagnosed with FH.

Patient-Reported Outcomes following Genetic Testing for Familial Hypercholesterolemia, Breast and Ovarian Cancer Syndrome, and Lynch Syndrome: A Systematic Review

Background: Patient-reported outcomes (PROs) and PRO measures (PROMs) are real-world evidence that can help capture patient experiences and perspectives regarding a clinical intervention such as genetic testing. Objective: To identify and capture methods and qualitative PRO themes among studies reporting PROs following genetic testing for FH, breast and ovarian cancer syndrome, and Lynch syndrome. Methods: A systematic review was conducted via PubMed/MEDLINE, EMBASE, and Yale University’s TRIP Medical Databases on articles published by April 2021. Results: We identified 24 studies published between 1996 and 2021 representing 4279 participants that reported PROs following genetic testing for FH, breast and ovarian cancer syndrome, and Lynch syndrome. Studies collected and reported PROs from validated PROM instruments (n = 12; 50%), validated surveys (n = 7; 26%), and interviews (n = 10; 42%). PRO themes ranged across all collection methods (e.g., psychological, knowledge, coping and satisfaction, concern about stigma/discrimination, etc.). Conclusions: Important gaps identified include (1) most studies (n = 18; 75%) reported PROs following genetic testing for breast and ovarian cancer, and (2) populations reporting PROs overall were largely of White/Caucasian/Northern European/Anglo-Saxon descent. We offer recommendations and describe real-world implications for the field moving forward.

The return of individual genomic results to research participants: design and pilot study of Tohoku Medical Megabank Project

Certain large genome cohort studies attempt to return the individual genomic results to the participants; however, the implementation process and psychosocial impacts remain largely unknown. The Tohoku Medical Megabank Project has conducted large genome cohort studies of general residents. To implement the disclosure of individual genomic results, we extracted the potential challenges and obstacles. Major challenges include the determination of genes/disorders based on the current medical system in Japan, the storage of results, prevention of misunderstanding, and collaboration of medical professionals. To overcome these challenges, we plan to conduct multilayer pilot studies, which deal with different disorders/genes. We finally chose familial hypercholesterolemia (FH) as a target disease for the first pilot study. Of the 665 eligible candidates, 33.5% were interested in the pilot study and provided consent after an educational "genetics workshop" on the basic genetics and medical facts of FH. The genetics professionals disclosed the results to the participants. All positive participants were referred to medical care, and a serial questionnaire revealed no significant psychosocial distress after the disclosure. Return of genomic results to research participants was implemented using a well-prepared protocol. To further elucidate the impact of different disorders, we will perform multilayer pilot studies with different disorders, including actionable pharmacogenomics and hereditary tumor syndromes.

Penetrance and outcomes at 1-year following return of actionable variants identified by genome sequencing

PURPOSE

We estimated penetrance of actionable genetic variants and assessed near-term outcomes following return of results (RoR).

METHODS

Participants (n = 2,535) with hypercholesterolemia and/or colon polyps underwent targeted sequencing of 68 genes and 14 single-nucleotide variants. Penetrance was estimated based on presence of relevant traits in the electronic health record (EHR). Outcomes occurring within 1-year of RoR were ascertained by EHR review. Analyses were stratified by tier 1 and non-tier 1 disorders.

RESULTS

Actionable findings were present in 122 individuals and results were disclosed to 98. The average penetrance for tier 1 disorder variants (67%; n = 58 individuals) was higher than in non-tier 1 variants (46.5%; n = 58 individuals). After excluding 45 individuals (decedents, nonresponders, known genetic diagnoses, mosaicism), ≥1 outcomes were noted in 83% of 77 participants following RoR; 78% had a process outcome (referral to a specialist, new testing, surveillance initiated); 68% had an intermediate outcome (new test finding or diagnosis); 19% had a clinical outcome (therapy modified, risk reduction surgery). Risk reduction surgery occurred more often in participants with tier 1 than those with non-tier 1 variants.

CONCLUSION

Relevant phenotypic traits were observed in 57% whereas a clinical outcome occurred in 19% of participants with actionable genomic variants in the year following RoR.

Leveraging population-based exome screening to impact clinical care: The evolution of variant assessment in the Geisinger MyCode research project

Exome and genome sequencing are increasingly utilized in research studies and clinical care and can provide clinically relevant information beyond the initial intent for sequencing, including medically actionable secondary findings. Despite ongoing debate about sharing this information with patients and participants, a growing number of clinical laboratories and research programs routinely report secondary findings that increase the risk for selected diseases. Recently, there has been a push to maximize the potential benefit of this practice by implementing proactive genomic screening at the population level irrespective of medical history, but the feasibility of deploying population-scale proactive genomic screening requires scaling key elements of the genomic data evaluation process. Herein, we describe the motivation, development, and implementation of a population-scale variant-first screening pipeline combining bioinformatics-based filtering with a manual review process to screen for clinically relevant findings in research exomes generated through the DiscovEHR collaboration within Geisinger's MyCode® research project. Consistent with other studies, this pipeline yields a screen-positive detection rate between 2.1 and 2.6% (depending on inclusion of those with prior indication-based testing) in 130,048 adult MyCode patient-participants screened for clinically relevant findings in 60 genes. Our variant-first pipeline affords cost and time savings by filtering out negative cases, thereby avoiding analysis of each exome one-by-one, as typically employed in the diagnostic setting. While research is still needed to fully appreciate the benefits of population genomic screening, MyCode provides the first demonstration of a program at scale to help shape how population genomic screening is integrated into routine clinical care.

Developing and Optimizing Innovative Tools to Address Familial Hypercholesterolemia Underdiagnosis: Identification Methods, Patient Activation, and Cascade Testing for Familial Hypercholesterolemia

Background:

Familial hypercholesterolemia (FH) is the most common cardiovascular genetic disorder and, if left untreated, is associated with increased risk of premature atherosclerotic cardiovascular disease, the leading cause of preventable death in the United States. Although FH is common, fatal, and treatable, it is underdiagnosed and undertreated due to a lack of systematic methods to identify individuals with FH and limited uptake of cascade testing.

Methods and Results:

This mixed-method, multi-stage study will optimize, test, and implement innovative approaches for both FH identification and cascade testing in 3 aims. To improve identification of individuals with FH, in Aim 1, we will compare and refine automated phenotype-based and genomic approaches to identify individuals likely to have FH. To improve cascade testing uptake for at-risk individuals, in Aim 2, we will use a patient-centered design thinking process to optimize and develop novel, active family communication methods. Using a prospective, observational pragmatic trial, we will assess uptake and effectiveness of each family communication method on cascade testing. Guided by an implementation science framework, in Aim 3, we will develop a comprehensive guide to identify individuals with FH. Using the Conceptual Model for Implementation Research, we will evaluate implementation outcomes including feasibility, acceptability, and perceived sustainability as well as health outcomes related to the optimized methods and tools developed in Aims 1 and 2.

Conclusions:

Data generated from this study will address barriers and gaps in care related to underdiagnosis of FH by developing and optimizing tools to improve FH identification and cascade testing.

Clinical outcomes of a genomic screening program for actionable genetic conditions

Purpose

Three genetic conditions—hereditary breast and ovarian cancer syndrome, Lynch syndrome, and familial hypercholesterolemia—have tier 1 evidence for interventions that reduce morbidity and mortality, prompting proposals to screen unselected populations for these conditions. We examined the impact of genomic screening on risk management and early detection in an unselected population.

Methods

Observational study of electronic health records (EHR) among individuals in whom a pathogenic/likely pathogenic variant in a tier 1 gene was discovered through Geisinger’s MyCode project. EHR of all eligible participants was evaluated for a prior genetic diagnosis and, among participants without such a diagnosis, relevant personal/family history, postdisclosure clinical diagnoses, and postdisclosure risk management.

Results

Eighty-seven percent of participants (305/351) did not have a prior genetic diagnosis of their tier 1 result. Of these, 65% had EHR evidence of relevant personal and/or family history of disease. Of 255 individuals eligible to have risk management, 70% (n = 179) had a recommended risk management procedure after results disclosure. Thirteen percent of participants (41/305) received a relevant clinical diagnosis after results disclosure.

Conclusion

Genomic screening programs can identify previously unrecognized individuals at increased risk of cancer and heart disease and facilitate risk management and early cancer detection.

A Global Review on the Utility of Genetic Testing for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder of cholesterol metabolism that affects an estimated 1/250 persons in the United States and abroad. FH is hallmarked by high low-density lipoprotein (LDL) cholesterol and an increased risk of premature atherosclerotic cardiovascular disease. This review summarizes recent global evidence showing the utility of FH genetic testing across diverse populations. Clinical and other qualitative outcomes following FH genetic testing were improved FH diagnosis, treatment initiation or continued treatment, treatment modification, improved total or LDL cholesterol levels, education on lifestyle management, and genetic counseling. This summary of evidence should be considered by those seeking overall evidence and knowledge gaps on the utility of FH genetic testing from a global perspective and for certain ethnic and age populations. These findings can be used to inform insurance policies and coverage decisions for FH genetic testing, policy recommendations to reduce the clinical and public health burden of FH, clinical practice and guidelines to improve the management of FH populations, and ongoing research involving FH genetic testing. We conclude that further investigations are needed to examine: (1) non-clinical outcomes following FH genetic testing; (2) patient-reported outcomes following FH genetic testing to convey patient experiences, values, and goals; and (3) clinical outcomes following FH genetic testing in non-Caucasian and pediatric populations in the United States and abroad.

Quantifying the polygenic contribution to variable expressivity in eleven rare genetic disorders

Rare genetic disorders (RGDs) often exhibit significant clinical variability among affected individuals, a disease characteristic termed variable expressivity. Recently, the aggregate effect of common variation, quantified as polygenic scores (PGSs), has emerged as an effective tool for predictions of disease risk and trait variation in the general population. Here, we measure the effect of PGSs on 11 RGDs including four sex-chromosome aneuploidies (47,XXX; 47,XXY; 47,XYY; 45,X) that affect height; two copy-number variant (CNV) disorders (16p11.2 deletions and duplications) and a Mendelian disease (melanocortin 4 receptor deficiency (MC4R)) that affect BMI; and two Mendelian diseases affecting cholesterol: familial hypercholesterolemia (FH; LDLR and APOB) and familial hypobetalipoproteinemia (FHBL; PCSK9 and APOB). Our results demonstrate that common, polygenic factors of relevant complex traits frequently contribute to variable expressivity of RGDs and that PGSs may be a useful metric for predicting clinical severity in affected individuals and for risk stratification.

Enablers and barriers to treatment adherence in heterozygous familial hypercholesterolaemia: a qualitative evidence synthesis

OBJECTIVES

Individuals with heterozygous familial hypercholesterolaemia (FH) are at high risk of developing cardiovascular disease (CVD). This risk can be substantially reduced with lifelong pharmacological and lifestyle treatment; however, research suggests adherence is poor. We synthesised the qualitative research to identify enablers and barriers to treatment adherence.

DESIGN

This study conducted a thematic synthesis of qualitative studies.

DATA SOURCES

MEDLINE, Embase, PsycINFO via OVID, Cochrane library and CINAHL databases and grey literature sources were searched through September 2018.

ELIGIBILITY CRITERIA

We included studies conducted in individuals with FH, and their family members, which reported primary qualitative data regarding their experiences of and beliefs about their condition and its treatment.

DATA EXTRACTION AND SYNTHESIS

Quality assessment was undertaken using the Critical Appraisal Skills Programme for qualitative studies. A thematic synthesis was conducted to uncover descriptive and generate analytical themes. These findings were then used to identify enablers and barriers to treatment adherence for application in clinical practice.

RESULTS

24 papers reporting the findings of 15 population samples (264 individuals with FH and 13 of their family members) across 8 countries were included. Data captured within 20 descriptive themes were considered in relation to treatment adherence and 6 analytical themes were generated: risk assessment; perceived personal control of health; disease identity; family influence; informed decision-making; and incorporating treatment into daily life. These findings were used to identify seven enablers (eg, 'commencement of treatment from a young age') and six barriers (eg, 'incorrect and/or inadequate knowledge of treatment advice') to treatment adherence. There were insufficient data to explore if the findings differed between adults and children.

CONCLUSIONS

The findings reveal several enablers and barriers to treatment adherence in individuals with FH. These could be used in clinical practice to facilitate optimal adherence to lifelong treatment thereby minimising the risk of CVD in this vulnerable population.

PROSPERO REGISTRATION NUMBER

CRD42018085946.

Barriers and Facilitators to Genetic Testing for Familial Hypercholesterolemia in the United States: A Review

Familial Hypercholesterolemia (FH) is an underdiagnosed condition in the United States (US) and globally, affecting an estimated 1/250 individuals. It is a genetic risk factor for premature cardiovascular disease and is responsible for an estimated 600,000 to 1.2 million preventable vascular events. Studies show that FH genetic testing can identify a causal gene variant in 60 to 80% of clinically suspected FH cases. However, FH genetic testing is currently underutilized in clinical settings in the US despite clinical recommendations and evidence supporting its use. Reasons for underutilization are not well understood. We conducted a literature review in the PubMed/MEDLINE database and eight peer-reviewed journals. After filtering for and reviewing 2340 articles against our inclusion criteria, we included nine commentaries or expert opinions and eight empirical studies reported between January 2014 and March 2019 in our review. After applying the Consolidated Framework for Implementation Research (CFIR), we identified a total of 26 potential barriers and 15 potential facilitators (estimated barrier to facilitator ratio of 1.73). We further estimated ratios of potential barriers to facilitators for each CFIR domain (Characteristics of Intervention, Outer Setting, Inner Setting, Characteristics of Individuals, and Process). Findings derived from our systematic approach to the literature and calculations of estimated baseline ratios of barriers and facilitators can guide future research to understand FH genetic testing implementation in diverse clinical settings. Our systematic approach to the CFIR could also be used as a model to understand or compare barriers and facilitators to other evidence-based genetic testing processes in health care settings in the US and abroad.

Improving the detection of familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a dominantly inherited disorder of low-density lipoprotein (LDL) catabolism, which if untreated causes lifelong elevated LDL-cholesterol (LDL-c), accelerated atherosclerosis and premature cardiovascular disease. Recent evidence suggests the prevalence of heterozygous FH is ∼1:220, making FH the most common autosomal dominant condition. Lowering LDL-c with statin and lifestyle therapy reduces the risk of cardiovascular events. Furthermore, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors significantly lower LDL-c in addition to statin therapy, and early outcome data suggest improved vascular outcomes with these agents in FH patients in addition to statins. However, the vast majority of people with FH still remain undiagnosed. The onus is on clinicians to identify kindreds with FH, as PCSK9 inhibitors, although expensive, are funded for patients with FH in Australia. Multiple strategies for detecting FH have been proposed. The detection of index cases can be achieved through applying electronic screening tools to general practice databases, universal screening of children during immunisation, and targeted screening of patients with premature cardiovascular disease. Advances in genomic technology have decreased costs of genetic testing, improved the understanding of the pathogenesis of FH and facilitated cascade screening. However, awareness of FH amongst clinicians and the general public still requires optimisation. This review outlines recent advances in FH detection, including emerging strategies and challenges for the next decade.