Incorporating Cascade Effects of Genetic Testing in Economic Evaluation: A Scoping Review of Methodological Challenges

Familial communication and cascade testing following elective genomic testing

Familial communication of results and cascade genetic testing (CGT) can extend the benefits of genetic screening beyond the patient to their at-risk relatives. While an increasing number of health systems are offering genetic screening as an elective clinical service, data are limited about how often results are shared and how often results lead to CGT. From 2018 to 2022, the Sanford Health system offered the Sanford Chip, an elective genomic test that included screening for medically actionable predispositions for disease recommended by the American College of Medical Genetics and Genomics for secondary findings disclosure, to its adult primary care patients. We analyzed patient-reported data about familial sharing of results and CGT among patients who received Sanford Chip results at least 1 year previously. Among the patients identified with medically actionable predispositions, 94.6% (53/56) reported disclosing their result to at least one family member, compared with 46.7% (423/906) of patients with uninformative findings (p < 0.001). Of the patients with actionable predispositions, 52.2% (12/23) with a monogenic disease risk and 12.1% (4/33) with a carrier status reported that their relatives underwent CGT. Results suggest that while the identification of monogenic risk during elective genomic testing motivates CGT in many at-risk relatives, there remain untested at-risk relatives who may benefit from future CGT. Findings identify an area that may benefit from increased genetic counseling and the development of tools and resources to encourage CGT for family members.

Cascade testing in mitochondrial diseases: a cross-sectional retrospective study

BACKGROUND

Cascade testing can offer improved surveillance and timely introduction of clinical management for the at-risk biological relatives. Data on cascade testing and costs in mitochondrial diseases are lacking. To address this gap, we performed a cross-sectional retrospective study to provide a framework for cascade testing in mitochondrial diseases, to estimate the eligibility versus real-time uptake of cascade testing and to evaluate the cost of the genetic diagnosis of index cases and the cost of predictive cascade testing.

METHODS

Data was collected through retrospective chart review. The variant inheritance pattern guided the identification of eligible first-degree relatives: (i) Males with mitochondrial DNA (mtDNA) single nucleotide variants (SNVs) - siblings and mothers. (ii) Females with mtDNA SNVs - siblings, mothers and offspring. (iii) Autosomal Dominant (AD) nuclear DNA (nDNA) variants - siblings, offspring and both parents. (iv) Autosomal Recessive (AR) nDNA variants - siblings.

RESULTS

We recruited 99 participants from the Adult Mitochondrial Disease Clinic in Sydney. The uptake of cascade testing was 55.2% in the mtDNA group, 55.8% in the AD nDNA group and 0% in AR nDNA group. Of the relatives in mtDNA group who underwent cascade testing, 65.4% were symptomatic, 20.5% were oligosymptomatic and 14.1% were asymptomatic. The mean cost of cascade testing for eligible first-degree relatives (mtDNA group: $694.7; AD nDNA group: $899.1) was lower than the corresponding index case (mtDNA group: $4578.4; AD nDNA group: $5715.1) (p < 0.001).

CONCLUSION

The demand for cascade testing in mitochondrial diseases varies according to the genotype and inheritance pattern. The real-time uptake of cascade testing can be influenced by multiple factors. Early diagnosis of at-risk biological relatives of index cases through cascade testing, confirms the diagnosis in those who are symptomatic and facilitates implementation of surveillance strategies and clinical care at an early stage of the disease.

Recommendations for Emerging Good Practice and Future Research in Relation to Family and Caregiver Health Spillovers in Health Economic Evaluations: A Report of the SHEER Task Force

BACKGROUND

Omission of family and caregiver health spillovers from the economic evaluation of healthcare interventions remains common practice. When reported, a high degree of methodological inconsistency in incorporating spillovers has been observed.

AIM

To promote emerging good practice, this paper from the Spillovers in Health Economic Evaluation and Research (SHEER) task force aims to provide guidance on the incorporation of family and caregiver health spillovers in cost-effectiveness and cost-utility analysis. SHEER also seeks to inform the basis for a spillover research agenda and future practice.

METHODS

A modified nominal group technique was used to reach consensus on a set of recommendations, representative of the views of participating subject-matter experts. Through the structured discussions of the group, as well as on the basis of evidence identified during a review process, recommendations were proposed and voted upon, with voting being held over two rounds.

RESULTS

This report describes 11 consensus recommendations for emerging good practice. SHEER advocates for the incorporation of health spillovers into analyses conducted from a healthcare/health payer perspective, and more generally inclusive perspectives such as a societal perspective. Where possible, spillovers related to displaced/foregone activities should be considered, as should the distributional consequences of inclusion. Time horizons ought to be sufficient to capture all relevant impacts. Currently, the collection of primary spillover data is preferred and clear justification should be provided when using secondary data. Transparency and consistency when reporting on the incorporation of health spillovers are crucial. In addition, given that the evidence base relating to health spillovers remains limited and requires much development, 12 avenues for future research are proposed.

CONCLUSIONS

Consideration of health spillovers in economic evaluations has been called for by researchers and policymakers alike. Accordingly, it is hoped that the consensus recommendations of SHEER will motivate more widespread incorporation of health spillovers into analyses. The developing nature of spillover research necessitates that this guidance be viewed as an initial roadmap, rather than a strict checklist. Moreover, there is a need for balance between consistency in approach, where valuable in a decision making context, and variation in application, to reflect differing decision maker perspectives and to support innovation.

Protocol for a Prospective, Observational Cost-effectiveness Analysis of Returning Secondary Findings of Genome Sequencing for Unexplained Suspected Genetic Conditions

PURPOSE

Although costly, genome-wide sequencing (GWS) detects an extensive range of variants, enhancing our ability to diagnose and assess risk for an increasing number of diseases. In addition to detecting variants related to the indication for testing, GWS can detect secondary variants in BRCA1, BRCA2, and other genes for which early intervention may improve health. As the list of secondary findings grows, there is increased demand for surveillance and management by multiple specialists, adding pressure to constrained health care budgets. Secondary finding testing is actively debated because some consider it opportunistic screening for future health risks that may not manifest. Given the economic implications of secondary finding testing and follow-up and its unproven clinical utility, the objective is to assess the incremental cost-effectiveness of secondary finding ascertainment per case detected and per unit of improved clinical utility in families of children with unexplained suspected genetic conditions undergoing clinical GWS.

METHODS

Those undergoing trio genome or exome sequencing are eligible for the study. Positive secondary finding index cases will be matched to negative controls (1:2) based on age group, primary result(s) type, and clinical indication. During the 2-year study, 71 cases and 142 matched controls are expected. Health service use will be collected in patients and 1 adult family member every 6 months. The per-child and per-dyad total cost will be determined by multiplying use of each resource by a corresponding unit price and summing all cost items. Costs will be estimated from the public and societal payer perspectives. The mean cost per child and per dyad for secondary finding-positive and secondary finding-negative groups will be compared statistically. If important demographic differences are observed between groups, ordinary least-squares regression, log transformation, or other nonparametric technique will be used to compare adjusted mean costs. The ratio of the difference in mean cost to the secondary finding yield will be used to estimate incremental cost-effectiveness. In secondary analyses, effectiveness will be estimated using the number of clinical management changes due to secondary findings or the Clinician-Reported Genetic Testing Utility Index (C-GUIDE) score, a validated measure of clinical utility. Sensitivity analysis will be undertaken to assess the robustness of the findings to variation in key parameters.

IMPLICATIONS

This study generates key evidence to inform clinical practice and funding allocation related to secondary finding testing. The inclusion of family members and a new measure of clinical utility represent important advancements in economic evaluation in genomics.

Actionability of unanticipated monogenic disease risks in newborn genomic screening: Findings from the BabySeq Project

Newborn genomic sequencing (NBSeq) to screen for medically important genetic information is of considerable interest but data characterizing the actionability of such findings, and the downstream medical efforts in response to discovery of unanticipated genetic risk variants, are lacking. From a clinical trial of comprehensive exome sequencing in 127 apparently healthy infants and 32 infants in intensive care, we previously identified 17 infants (10.7%) with unanticipated monogenic disease risks (uMDRs). In this analysis, we assessed actionability for each of these uMDRs with a modified ClinGen actionability semiquantitative metric (CASQM) and created radar plots representing degrees of penetrance of the condition, severity of the condition, effectiveness of intervention, and tolerability of intervention. In addition, we followed each of these infants for 3-5 years after disclosure and tracked the medical actions prompted by these findings. All 17 uMDR findings were scored as moderately or highly actionable on the CASQM (mean 9, range: 7-11 on a 0-12 scale) and several distinctive visual patterns emerged on the radar plots. In three infants, uMDRs revealed unsuspected genetic etiologies for existing phenotypes, and in the remaining 14 infants, uMDRs provided risk stratification for future medical surveillance. In 13 infants, uMDRs prompted screening for at-risk family members, three of whom underwent cancer-risk-reducing surgeries. Although assessments of clinical utility and cost-effectiveness will require larger datasets, these findings suggest that large-scale comprehensive sequencing of newborns will reveal numerous actionable uMDRs and precipitate substantial, and in some cases lifesaving, downstream medical care in newborns and their family members.

Access to novel drugs and therapeutics for children and youth: Eliciting citizens' values to inform public funding decisions

INTRODUCTION

The unique evidentiary, economic and ethical challenges associated with health technology assessment (HTA) of precision therapies limit access to novel drugs and therapeutics for children and youth, for whom such challenges are amplified. We elicited citizens' perspectives about values-based criteria relevant to the assessment of paediatric precision therapies to inform the development of a child-tailored HTA framework.

METHODS

We held four citizen panels virtually in May-June 2021, informed by a plain-language citizen brief summarizing global and local evidence about the challenges, policy and programmatic options and implementation strategies related to enhancing access to precision therapies for Canadian children and youth. Panellists were recruited through a nationally representative database, medical/patient networks and social media. We inductively coded and thematically analysed panel transcripts to generate themes and identify priority values.

RESULTS

The perspectives of panellists (n = 45) coalesced into four overlapping themes, with attendant subthemes, relevant to a child-tailored HTA framework: (1) Childhood Distinctions: vulnerability, 'fair innings', future potential, family impacts; (2) Voice: agency of children and youth; lived versus no lived experience; (3) One versus Many: disease severity, rarity, equity, unmet need and (4) Health System Governance: funding, implementation inequities, effectiveness and safety. Participants broadly agreed that childhood distinctions, particularly family impacts, justify child-tailored HTA. Dissent arose over whose voice should inform HTA and how such perspectives are best incorporated.

CONCLUSIONS

Citizens can offer unique insights into criteria relevant to the development or revision of HTA frameworks to capture holistic, societally responsive dimensions of value attached to unique contexts or populations, including children. Balancing the hopes and expectations of patients and caregivers for access to expensive but potential life-altering therapies against the opportunity costs borne by encompassing health systems is a fundamental challenge that will require rigorous methods to elicit, weigh and reconcile varied views.

PATIENT OR PUBLIC CONTRIBUTION

A patient advocate served on the steering committee of this study and co-authored this article. Key informants for the Citizen Brief included patient advocates and caregivers; a separate patient advocate reviewed the Brief before dissemination. Qualitative and quantitative data were collected from the general public and caregivers of children, with written consent.

Swiss cost-effectiveness analysis of universal screening for Lynch syndrome of patients with colorectal cancer followed by cascade genetic testing of relatives

Background

We estimated the cost-effectiveness of universal DNA screening for Lynch syndrome (LS) among newly diagnosed patients with colorectal cancer (CRC) followed by cascade screening of relatives from the Swiss healthcare system perspective.

Methods

We integrated decision trees with Markov models to calculate incremental cost per quality-adjusted life-year saved by screening all patients with CRC (alternative strategy) compared with CRC tumour-based testing followed by DNA sequencing (current strategy).

Results

The alternative strategy has an incremental cost-effectiveness ratio of CHF65 058 compared with the current strategy, which is cost-effective according to Swiss standards. Based on annual incidence of CRC in Switzerland, universal DNA screening correctly identifies all 123 patients with CRC with LS, prevents 17 LS deaths and avoids 19 CRC cases, while the current strategy leads to 32 false negative results and 253 LS cases lost to follow-up. One way and probabilistic sensitivity analyses showed that universal DNA testing is cost-effective in around 80% of scenarios, and that the cost of DNA testing and the number of invited relatives per LS case determine the cost-effectiveness ratio.

Conclusion

Results can inform policymakers, healthcare providers and insurance companies about the costs and benefits associated with universal screening for LS and cascade genetic testing of relatives.

Assessing Value in Child Health

Assessing value in child health is increasingly important as health care systems face difficult choices with regard to what services and programs for children to fund and deliver [...]