Economic evaluation of cystic fibrosis screening: A review of the literature

Next-Generation Sequencing for Screening Analysis of Cystic Fibrosis: Spectrum and Novel Variants in a South-Central Italian Cohort

The incidence of cystic fibrosis (CF) and the spectrum of cystic fibrosis transmembrane conductance regulator (CFTR) gene variants differ among geographic regions. Differences in CF carrier distribution are also reported among Italian regions. We described the spectrum of the CFTR variants observed in a large group of subjects belonging from central-southern Italy. We also provide a predictive evaluation of the novel variants identified. CFTR screening was performed in a south-central Italian cohort of 770 subjects. We adopted a next-generation sequencing (NGS) approach using the Devyser CFTR NGS kit on the Illumina MiSeq System coupled with Amplicon Suite data analysis. Bioinformatics evaluation of the impact of novel variants was described. Overall, the presence of at least one alternative allele in the CFTR gene was recorded for 23% of the subjects, with a carrier frequency of CF pathogenic variants of 1:12. The largest sub-group corresponded to the heterozygous carriers of a variant with a conflicting interpretation of pathogenicity. The common CFTR p.(Phe508del) pathogenic variants were identified in 37% of mutated subjects. Bioinformatics prediction supported a potential damaging effect for the three novel CFTR variants identified: p.(Leu1187Phe), p.(Pro22Thr), and c.744-3C > G. NGS applied to CF screening had the benefit of: effectively identifying asymptomatic carriers. It lies in a wide overview of CFTR variants and gives a comprehensive picture of the carrier prevalence. The identification of a high number of unclassified variants may represent a challenge whilst at the same time being of interest and relevance for clinicians.

Economic evaluation of reproductive carrier screening for recessive genetic conditions: a systematic review

INTRODUCTION

Autosomal recessive (AR) and x-linked (XL) conditions are rare but collectively common which impact millions of people globally on morbidity, mortality and costs. Advanced medical technologies allow prospective parents to make informed reproductive decisions to avoid having affected children. Economic evaluations targeting on reproductive carrier screening (RCS) for AR and/or XL conditions have been conducted, but there has not been a systematic review in this area.

AREAS COVERED

A systematic search of economic evaluations for RCS was undertaken using the following databases - EMBASE, MEDLINE and SCOPUS. The search strategy was designed to capture full economic evaluations related to RCS since 1990. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) strategy. The included 23 studies adopted various types of methodologies to conduct economic evaluations. The majority of studies examined a single condition. The various clinical strategies and screened conditions caused the different cost-effectiveness conclusions in the published studies.

EXPERT OPINION

Establishing a validated and practical clinical strategy of RCS and investigating the cost-effectiveness of multiple conditions in one economic evaluation are critical for implementing RCS in the future. Further economic evaluations are essential to provide evidence-based practice for decision-makers.

The cost-effectiveness of genotyping versus sequencing for prenatal cystic fibrosis carrier screening

OBJECTIVE

We investigated the cost-effectiveness of three sequential prenatal cystic fibrosis (CF) carrier screening strategies: genotyping both partners, genotyping one partner then sequencing the second, and sequencing both partners.

METHOD

A decision-analytic model compared the strategies in a theoretical cohort of four million pregnant couples in the US population and five racial/ethnic sub-populations. Inputs were obtained from literature and varied in sensitivity analysis. Outcomes included cost per quality-adjusted life year (QALY), missed carrier couples, affected newborns, missed prenatal diagnoses, terminations, and procedure-related losses. The cost-effectiveness threshold was $100,000/QALY.

RESULTS

Sequencing both partners identified 1099 carrier couples that were missed by genotyping both partners, leading to 273 fewer missed prenatal diagnoses, 152 more terminations, and 152 fewer affected newborns. A similar trend was observed in the genotyping followed by sequencing strategy. The incremental cost-effectiveness ratio of genotyping followed by sequencing compared to genotyping both partners was $180,004/QALY and the incremental cost-effectiveness ratio of sequencing both partners compared to genotyping followed by sequencing was $17.6 million/QALY. Sequencing both partners was cost-effective below $339 per test, genotyping/sequencing between $340 and $1837, and genotyping both partners above $1838. Sequencing was not cost-effective among five racial/ethnic sub-populations.

CONCLUSION

Despite improved outcomes, sequencing for prenatal CF carrier screening was not cost-effective compared to genotyping. The clinical significance of the incremental cost-effectiveness of CF carrier screening is a matter of deliberation for public policy debate.

Further Evidence That the CFTR Variant c.2620-6T>C Is Benign

The c.2620-6T>C variant in the CFTR gene is a rare variant about which little is known. We present an asymptomatic adult who has this variant as well as the well described delta F508 pathogenic variant in transpresentation. This patient provides additional evidence that this is a benign polymorphism.

VP103 Health Technology Assessment Of Genetic Tests For Cystic Fibrosis Carrier Screening In Italy

INTRODUCTION:

Cystic Fibrosis (CF) is a genetic disorder caused by mutations in CFTR gene. In Italy, reported prevalence is approximately .70 per 10,000 inhabitants (1). The practice and recommendations for Cystic Fibrosis carrier screening are very heterogeneous in Europe. A proposal of a carrier genetic test in the general population raises many questions. Health Technology Assessment (HTA) could offer a sound methodological basis for this evaluation. The aim of this work was to summarize the available evidence, using the HTA approach, on the genetic tests for Cystic Fibrosis carrier screening.

METHODS:

A systematic literature search was used to find the best available international and national evidence on genetics test for CF carrier screening. In this report, we specifically addressed the health problem of disease, description and technical characteristics of tests – its analytic and clinical validity, and clinical utility. Economic evaluation of different scenarios was synthesized from the literature. Ethical, organizational, and social aspects of CF and genetic screening were also considered.

RESULTS:

Several screening strategies have been evaluated in the literature and screening options can be characterized by different timing, model and place of screening (2). The reported cost of a screening test ranged from EUR25 to EUR212 (3). Estimated life time cost of care for CF patients ranged from EUR291,048 to EUR1,105,452. Ethical analysis emphasized that the use of these tests is an advantage in terms of the acquisition of knowledge and of responsible management of choices, but at the same time raises many ethical questions. Social considerations reported among patients and their families an overall positive attitude toward population CF carrier screening.

CONCLUSIONS:

The advances in the molecular genetics technology have made CF carrier testing reliable and affordable. The multidisciplinary approach of this HTA provided an evidence-based evaluation of genetic tests and offers a firm scientific background for the decision-makers to consider the implementation of a screening for Cystic Fibrosis carriers into the Italian health care system.

Carrier screening by next-generation sequencing: health benefits and cost effectiveness

BACKGROUND

Compared with conventional genotyping, which typically tests for a limited number of mutations, next-generation DNA sequencing (NGS) provides increased accuracy for carrier screening. The objective of this study was to evaluate the cost effectiveness of carrier screening using NGS versus genotyping for 14 of the recessive disorders for which medical society guidelines recommend screening.

METHODS

Data from published literature, population surveys, and expert opinion were used to develop a decision tree model capturing decisions and outcomes related to carrier screening and reproductive health.

RESULTS

Modeling a population of 1,000,000 couples that was representative of the United States population and that contained 83,421 carriers of pathogenic mutations, carrier screening using NGS averted 21 additional affected births as compared with genotyping, and reduced costs by approximately $13 million. As compared with no screening, NGS carrier screening averted 223 additional affected births. The results are sensitive to assumptions regarding mutation detection rates and carrier frequencies in multiethnic populations.

CONCLUSION

This study demonstrated that NGS-based carrier screening offers the greater benefit in clinical outcomes and lower total healthcare cost as compared with genotyping.

Human Genetics Society of Australasia position statement: population-based carrier screening for cystic fibrosis

Since the discovery in 1989 that mutations in cystic fibrosis transmembrane conductance regulator (CFTR) underlie cystic fibrosis (CF), the most common life shortening genetic disorder in Caucasians, it has been possible to identify heterozygous mutation carriers at risk of having affected children. The Human Genetics Society of Australasia has produced a position statement with recommendations in relation to population-based screening for CF. These include: (1) that screening should be offered to all relatives of people with or carriers of CF (cascade testing) as well as to all couples planning to have children or who are pregnant; (2) the minimum CFTR mutation panel to be tested consists of 17 mutations which are those mutations that are associated with typical CF and occur with a frequency of 0.1% or higher among individuals diagnosed with CF in Australasia; (3) that genetic counselling is offered to all couples where both members are known to have one or two CFTR mutations and that such couples are given the opportunity to meet with a physician with expertise in the management of CF as well as a family/individual affected by the condition.

Cystic fibrosis: to screen or not to screen? Involving a Citizens' jury in decisions on screening carrier

Context

In recent years, the continuous improvements in molecular biology techniques have made it possible to detect carriers for several genetic conditions, including cystic fibrosis (CF). In some countries, CF carrier screening is offered to increasing subset of the general population.

Offering of carrier screening at a population level should not be decided by local health authorities only, without consulting citizens' preferences. One way to involve citizens in the decision process might be to a Citizens' jury, a method of deliberative democracy.

Objective

The object of the study is to produce a recommendation statement about CF carrier screening using a Citizens' jury. As this is a new method in the field, the study also provided the opportunity to evaluate its effectiveness.

Design

The project is designed and managed by an executive committee. The whole process is superintended by a multidisciplinary scientific committee. The 16 members of the jury attend a 1 day meeting, assisted by a non‐medical and unbiased facilitator. Informative material was prepared and distributed 15 days before the jury meeting; during the meeting, experts and witnesses interact directly with all the jurors through questions and answers.

Results

All except one member of the jury felt positively about the Health Service actively providing population carrier screening for CF. The final statement was available to public, clinicians, researchers and decision‐makers.

Discussion

In general, a Citizens' jury is a feasible method for involving citizens in public health decision‐making process and in particular for obtaining a community view about CF carrier screening.

Cystic fibrosis carrier screening

Carrier screening for cystic fibrosis (CF) has been available since the early 1990s, yet there are few programs, and none funded as part of a national health care strategy. The aim of this paper is to provide a description of carrier screening for CF and examine the progress that has been made towards the establishment of universal population-based carrier screening programs. This is an evidence based commentary on population-based carrier screening for CF. Peak body recommendations were examined and existing programs for CF carrier screening are reviewed. The attitudes from the non-CF community, CF healthcare professionals and people with CF were studied. Data from health economic assessments is examined. The future of carrier screening for CF in the context of advancing genetic technologies and potentially curative therapies is considered.

Attitudes of health care professionals toward carrier screening for cystic fibrosis. A review of the literature

Recent technological developments in molecular genetics facilitate the large-scale detection of inherited genetic disorders and allow an increasing number of genetic conditions to be screened for (American College of Medical Genetics 2012). This technological evolution creates the background which makes reflection necessary about the desirability to offer community-based (preconception) carrier screening in the healthcare system. A positive attitude of potential providers is vital to the success of a screening program. Therefore, the objective of this article is to elaborate a review of the attitudes of healthcare professionals toward carrier screening. Examination of existing carrier screening programs could provide such information. The literature review will be focused on the attitudes toward carrier screening for cystic fibrosis (CF). The databases Pubmed and Web of Science, as well as the interface Google Scholar, were searched using the keywords for the period 1990-2011. Studies were selected if they were published in a peer-reviewed journal in English and described the attitudes of potential providers toward carrier screening. Eleven studies were retrieved describing the attitudes toward carrier screening for CF. In total, seven studies reported attitudes toward the best time for carrier screening; four studies described opinions toward the best setting to offer CF carrier screening; six studies investigated the willingness to be involved in a carrier screening program, and in total 11 articles reported the concerns about offering carrier screening. Ten papers described a general attitude toward carrier screening. We can conclude that health care providers state willingness to be involved in a carrier screening program, but there is need for appropriate education as well as adequate support given the time constraints already present in consultation. The prospect of an increasing number of genetic disorders for which screening becomes possible, and the potential increasing demand for such screening in the future calls for the need for further debate on the desirability of carrier screening and relevant questions such as the conditions screened, the providers involved, the information provision, and counseling.

Heterogeneity of risk within racial groups, a challenge for public health programs

Targeting high-risk populations for public health interventions is a classic tool of public health promotion programs. This practice becomes thornier when racial groups are identified as the at-risk populations. I present the particular ethical and epistemic challenges that arise when there are low-risk subpopulations within racial groups that have been identified as high-risk for a particular health concern. I focus on two examples. The black immigrant population does not have the same hypertension risk as US-born African Americans. Similarly, Finnish descendants have a far lower rate of cystic fibrosis than other Caucasians. In both cases the exceptional nature of these subpopulations has been largely ignored by the designers of important public health efforts, including the recent US government dietary recommendations. I argue that amending the publicly-disseminated risk information to acknowledge these exceptions would be desirable for several reasons. First, recognizing low-risk subpopulations would allow more efficient use of limited resources. Communicating this valuable information to the subpopulations would also promote truth-telling. Finally, presenting a more nuanced empirically-supported representation of which groups are at known risk of diseases (not focusing on mere racial categories) would combat harmful biological race essentialist views held by the public.

The cost-effectiveness of prenatal screening for spinal muscular atrophy

OBJECTIVE

We sought to investigate the cost-effectiveness of prenatal screening for spinal muscular atrophy (SMA).

STUDY DESIGN

A decision analytic model was created to compare a policy of universal SMA screening to that of no screening. The primary outcome was incremental cost per maternal quality-adjusted life year. Probabilities, costs, and outcomes were estimated through literature review. Univariate and multivariate sensitivity analyses were performed to test the robustness of our model to changes in baseline assumptions.

RESULTS

Universal screening for SMA is not cost-effective at $4.9 million per quality-adjusted life year. In all, 12,500 women need to be screened to prevent 1 case of SMA, at a cost of $5.0 million per case averted. Our results were most sensitive to the baseline prevalence of disease.

CONCLUSION

Universal prenatal screening for SMA is not cost-effective. For populations at high risk, such as those with a family history, SMA testing may be a cost-effective strategy.

Population-based carrier screening for cystic fibrosis in Victoria: the first three years experience

BACKGROUND

Cystic fibrosis (CF) is the most common inherited, life-shortening condition affecting Australian children. The carrier frequency is one per 25 and most babies with CF are born to parents with no family history. Carrier testing is possible before a couple has an affected infant.

AIMS

To report the outcomes of a carrier screening program for CF.

METHOD

Carrier screening was offered to women and couples planning a pregnancy, or in early pregnancy, through obstetricians and general practitioners in Victoria, Australia. Samples were collected by cheek swab and posted to the laboratory. Twelve CFTR gene mutations were tested. Carriers were offered genetic counselling and partner testing. Carrier couples were offered prenatal testing by chorionic villous sampling (CVS) if pregnant. The number of people tested, carriers detected and pregnancy outcomes were recorded from January 2006 to December 2008.

RESULTS

A total of 3200 individuals were screened (3000 females). One hundred and six carriers were identified (one per 30, 95% confidence interval one per 25, one per 36). All carrier partners were screened, and nine carrier couples identified (total carriers 115). Ninety-six individuals (83%) were carriers of the p.508del mutation. Of the nine carrier couples, six were pregnant at the time of screening (five natural conception and one in vitro fertilisation) and all had CVS (mean gestation 12.5 weeks). Two fetuses were affected, three were carriers and one was not a carrier. Termination of pregnancy was undertaken for the affected fetuses.

CONCLUSION

Carrier screening for CF by obstetricians and general practitioners by cheek swab sample can be successfully undertaken prior to pregnancy or in the early stages of pregnancy.

The valuation of prenatal life in economic evaluations of perinatal interventions

Perinatal interventions delivered during the prenatal period have the potential to directly impact prenatal life. The decision on when to begin 'counting' the life of an infant in the calculus has received little attention in previous economic evaluations of perinatal interventions. We illustrate, using data from a recent trial-based economic evaluation of magnesium sulphate given to women with pre-eclampsia to prevent eclampsia, how different definitions of when human life commences can have a significant impact upon cost-effectiveness estimates based on composite outcome measures such as life years or quality-adjusted life years gained or disability-adjusted life years averted. Further, we suggest ways in which methods in this area can be improved.

Population screening for reproductive risk for single gene disorders in Australia: now and the future

Abstract As the results of the Human Genome Project are realized, it has become technically possible to identify carriers of numerous autosomal and X-linked recessive disorders. Couples at risk of having a child with one of these conditions have a number of reproductive options to avoid having a child with the condition should they wish. In Australia the haemoglobinopathies are the only group of conditions for which population screening is widely offered and which is government funded. In some Australian states there are also population screening programs for cystic fibrosis and autosomal recessive conditions more common in Ashkenazi Jewish individuals which are generally offered on a user pays basis. It is predicted that as consumer demand increases and testing becomes cheaper, that many people planning or in the early stages of pregnancy will have carrier screening for multiple genetic conditions. This will have significant implications for genetic counseling, laboratory and prenatal testing resources. In addition such screening raises a number of ethical issues including the value of lives of those born with genetic conditions for which screening is available.