A cost-effectiveness analysis of cell free DNA as a replacement for serum screening for Down syndrome

Prenatal Screening and Diagnosis: Time for a Paradigm Shift

Recent advances in genetics and imaging have ushered substantial breakthroughs in screening and diagnosis for chromosomal and structural abnormalities. Thus, it is imperative that health care providers caring for pregnant individuals should reexamine established practices in prenatal screening and diagnosis. In the past, screening for chromosomal abnormalities was based almost entirely on Down syndrome. Pregnant individuals aged > 35 years were considered at "high risk" or of "advanced maternal age" based on age alone; however, the advent of tests with high sensitivity for prenatal detection of chromosomal abnormalities should lead to abandoning that concept, at least from the perspective of chromosomal abnormalities. Given that first-trimester and second-trimester screenings will fail to detect between 5 and 20% of Down syndrome, in most situations, noninvasive testing with cell-free DNA should be the first-line screen for Down syndrome. The fact that over 99% of fetuses with Down syndrome will be detected prenatally with cell-free DNA gives other fetal chromosomal and structural abnormalities increasing prominence. Chromosomal microarray analysis (CMA) permits prenatal detection of several clinically important chromosomal aberrations that cannot be detected by karyotype and may exist in structurally normal fetuses with low-risk cell-free DNA screening. As such, CMA should be more readily conducted when invasive testing is performed, regardless of the presence of a structural abnormality. Isolated sonographic "soft markers" have no clinical significance in patients who have normal cell-free DNA screening, can cause unwarranted anxiety and a negative impact on pregnancy, and perhaps it is time to stop discussing them. Detailed first-trimester ultrasound allows early detection of several severe fetal anomalies and, therefore, in settings with adequately trained personnel and resources, should be used more frequently. This opinion traces the evolution of prenatal screening and diagnosis and advocates for a paradigm shift that aligns with recent developments in prenatal screening and diagnostic capabilities. KEY POINTS: · Noninvasive prenatal testing with cell-free DNA should be available to all pregnant individuals.. · Chromosomal microarray should be available to all pregnant individuals undergoing amniocentesis.. · Patients >35 years with low-risk screening are not at "high risk" for chromosomal abnormalities..

A Cost-Effectiveness Analysis of Screening Strategies Involving Non-Invasive Prenatal Testing for Trisomy 21

Introduction

In accordance with social development, the proportion of advanced maternal age (AMA) increased and the cost of non-invasive prenatal testing (NIPT) decreased.

Objective

We aimed to investigate the benefits and cost-effectiveness of NIPT as primary or contingent strategies limited to the high-risk population of trisomy 21 (T21).

Methods

Referring to parameters from publications or on-site verification, a theoretical model involving 1,000,000 single pregnancies was established. We presented five screening scenarios, primary NIPT (Strategy 1), contingent NIPT after traditional triple serum screening higher than 1/300 or 1/1,000 (Strategy 2-1 or 2-2), and age-based Strategy 3. Strategy 3 was stratified, with the following options: (1) for advanced maternal age (AMA) of 40 years and more, diagnostic testing was offered, (2) for AMA of 35-39 years, NIPT was introduced, (3) if younger than 35 years of age, contingent NIPT with risk higher than 1:300 (Strategy 3-1) or 1:1,000 (Strategy 3-2) will be offered. The primary outcome was an incremental cost analysis on the baseline and alternative assumptions, taking aging society, NIPT price, and compliance into consideration. The strategy was "appropriate" when the incremental cost was less than the cost of raising one T21 child (0.215 million US$). The second outcome included total cost, cost-effect, cost-benefit analysis, and screening efficiency.

Results

Strategy1 was costly, while detecting most T21. Strategy 2-1 reduced unnecessary prenatal diagnosis (PD) and was optimal in total cost, cost-effect, and cost-benefit analysis, nevertheless, T21 detection was the least. Strategy 3 induced most of the PD procedures. Then, setting Strategy2-1 as a baseline for incremental cost analysis, Strategy 3-1 was appropriate. In sensitivity analysis, when the NIPT price was lower than 47 US$, Strategy 1 was the most appropriate. In a society with more than 20% of people older than 35 years of age, the incremental cost of Strategy 3-2 was proper.

Conclusion

Combined strategies involving NIPT reduced unnecessary diagnostic tests. The AMA proportion and NIPT price played critical roles in the strategic decision. The age-based strategy was optimal in incremental cost analysis and was presented to be prominent as AMA proportion and NIPT acceptance increased. The primary NIPT was the most effective, but only at a certain price, it became the most cost-effective strategy.

Cost of providing cell-free DNA screening for Down syndrome in Finland using different strategies

OBJECTIVES

A financial analysis is carried out to assess costs and benefits of providing cell-free DNA screening in Finland, using different strategies.

METHODS

Three cell-free DNA screening strategies are considered: Primary, all women; Secondary, those with positive Combined test; and Contingent, the 10-30% with the highest Combined test risks. Three costs are estimated: additional cost for 10,000 pregnancies compared with the Combined test; 'marginal' cost of avoiding a Down syndrome birth which occurs in a pregnancy that would have been false-negative using the Combined test; and marginal cost of preventing the iatrogenic loss of a non-Down syndrome birth which occurs in a pregnancy that would have been false-positive.

RESULTS

Primary cell-free DNA will require additional funds of €250,000. The marginal cost per Down syndrome birth avoided is considerably less than the lifetime medical and indirect cost; the marginal cost per unaffected iatrogenic fetal loss prevented is higher than one benefit measure but lower than another. If the ultrasound component of the Combined test is retained, as would be in Finland, the additional funds required rise to €992,000. Secondary cell-free DNA is cost-saving as is a Contingent strategy with 10% selected but whilst when 20-30% costs rise they are much less than for the Primary strategy and are cost-beneficial.

CONCLUSIONS

When considering the place of cell-free DNA screening it is important to make explicit the additional and marginal costs of different screening strategies and the associated benefits. Under most assumptions the balance is favorable for Contingent screening.

Performance of a universal prenatal screening program incorporating cell-free fetal DNA analysis in Ontario, Canada

BACKGROUND:

The emergence of cell-free fetal DNA (cfDNA) testing technology has disrupted the landscape of prenatal screening for trisomies 21 (T21) and 18 (T18). Publicly funded systems around the world are grappling with how to best integrate this more accurate but costly technology, as there is limited evidence about its incremental value in real-world conditions. The objectives of this study were to describe the population-based performance of Ontario’s prenatal screening program, which incorporates publicly funded cfDNA screening for specific indications, and the effect of cfDNA testing on the screening and diagnostic choices made by pregnant people.

METHODS:

We conducted a retrospective, descriptive cohort study using routinely collected data from Better Outcomes & Registry Network (BORN) Ontario, which captures linked population data for prenatal and neonatal health encounters across Ontario. We included all singleton pregnancies with an estimated due date between Sept. 1, 2016, and Mar. 31, 2019, that underwent publicly funded prenatal screening in Ontario, and a comparison cohort from Apr. 1, 2012, and Mar. 31, 2013. We assessed performance of the screening program for the detection of T21 or T18 by calculating sensitivity, specificity, positive predictive value and negative predictive value against diagnostic cytogenetic results or birth outcomes. We assessed the impact of the program by calculating the proportion of T21 screen-positive pregnancies undergoing subsequent cfDNA screening and invasive prenatal diagnostic testing.

RESULTS:

The study cohort included 373 682 pregnancies. The prenatal screening program had an uptake of 69.9%, a screen-positive rate and sensitivity of 1.6% and 89.9% for T21, and 0.2% and 80.5% for T18, respectively. The test failure rate for cfDNA screening was 2.2%. Invasive prenatal diagnostic testing decreased from 4.4% in 2012–2013 to 2.4% over the study period; 65.2% of pregnant people who received a screen-positive result from cfDNA testing went on to have invasive prenatal diagnostic testing.

INTERPRETATION:

This publicly funded screening program, incorporating cfDNA analysis for common aneuploidies, showed robust performance, a substantial reduction in invasive prenatal diagnostic testing and that pregnant people exercise autonomy in their choices about prenatal screening and diagnosis.

First trimester screening for aneuploidy: may combined test and fetal DNA work together?

INTRODUCTION

The purpose of the study was to evaluate the screening performance of combined test (based on the measurement of nuchal translucency, pregnancy-associated plasma protein A, free β-human chorionic gonadotropin, and maternal age) and fetal DNA screening (NIPS) for trisomies 21 (T21), 18 (T18), and 13 (T13).

MATERIAL AND METHODS

Women who accepted screening had a first-trimester combined test (pregnancy-associated plasma protein A, free β-human chorionic gonadotropin, nuchal translucency interpreted with maternal age) and fetal DNA.

RESULTS

Among 302 women screened (including 4 with affected pregnancies), our study demonstrated that DNA screening for trisomies 21, 18, and 13 achieved a detection rate of 100% with a false-positive rate of 0.02%, overcoming the traditional combined test with 75% of sensitivity and 4.7% of false-positive rate. In particular, fetal DNA may be useful in case of intermediate risk, in order to avoid invasive diagnostic procedures such villocentesis and amniocentesis. Because of fetal DNA costs, it can be used in clinical practice as a second step screening in case of intermediate or high risk at combined test.

CONCLUSION

Fetal DNA screening may be successfully implemented in routine care, achieving a high detection rate, low false-positive rate, and, consequently, greater safety with fewer invasive diagnostic tests than other methods of screening.

Prenatal genetic diagnosis: Fetal therapy as a possible solution to a positive test

BACKGROUND

Fetal abnormalities cause 20% of perinatal deaths. Advances in prenatal genetic and other types of screening offer great opportunities for identifying high risk pregnancies.

METHODS

Through a literature search, here we summarise what are the prenatal diagnostic technique that are being used and how those techniques may allow for prenatal interventions.

RESULTS

Next generation sequencing and non-invasive prenatal testing are fundamental for clinical diagnostics because of their sensitivity and accuracy in identifying point mutations, aneuploidies, and microdeletions, respectively. Timely identification of genetic disorders and other fetal abnormalities enables early intervention, such as in-utero gene therapy, fetal drug therapy and prenatal surgery.

CONCLUSION

Prenatal intervention is mainly focused on conditions that may cause death or lifelong disabilities, like spina bifida, congenital diaphragm hernia and sacrococcygeal teratoma; and may be an alternative therapeutic option to termination of pregnancy. However, it is not yet widely available, due to lack of specialized centers.

Cost-effectiveness of prenatal screening and diagnostic strategies for Down syndrome: A microsimulation modeling analysis

Objectives

Down syndrome (DS) is the most frequently occurring fetal chromosomal abnormality and different prenatal screening strategies are used for determining risk of DS worldwide. New non-invasive prenatal testing (NIPT), which uses cell-free fetal DNA in maternal blood can provide benefits due to its higher sensitivity and specificity in comparison to conventional screening tests. This study aimed to assess the cost-effectiveness of using population-level NIPT in fetal aneuploidy screening for DS.

Methods

We developed a microsimulation decision-analytic model to perform a probabilistic cost-effectiveness analysis (CEA) of prenatal screening and diagnostic strategies for DS. The model followed individual simulated pregnant women through the pregnancy pathway. The comparators were serum-only screening, contingent NIPT (i.e., NIPT as a second-tier screening test) and universal NIPT (i.e., NIPT as a first-tier screening test). To address uncertainty around the model parameters, the expected values of costs and quality-adjusted life-years (QALYs) in the base case and all scenario analyses were obtained through probabilistic analysis from a Monte Carlo simulation.

Results

Base case and scenario analyses were conducted by repeating the micro-simulation 1,000 times for a sample of 45,605 pregnant women per the population of British Columbia, Canada (N = 4.8 million). Preliminary results of the sequential CEAs showed that contingent NIPT was a dominant strategy compared to serum-only screening. Compared with contingent NIPT, universal NIPT at the current test price was not cost-effective with an incremental cost-effectiveness ratio over $100,000/QALY. Contingent NIPT also had the lowest cost per DS case detected among these three strategies.

Conclusion

Including NIPT in existing prenatal screening for DS is shown to be beneficial over conventional testing. However, at current prices, implementation of NIPT as a second-tier screening test is more cost-effective than deploying it as a universal test.

Cost-effectiveness of five prenatal screening strategies for trisomies and other unbalanced chromosomal abnormalities: model-based analysis

OBJECTIVE

To evaluate the cost-effectiveness of five prenatal screening strategies for trisomies (13/18/21) and other unbalanced chromosomal abnormalities (UBCA), following the introduction of cell-free DNA (cfDNA) analysis.

METHODS

A model-based cost-effectiveness analysis was performed to estimate prevalence, safety, screening-program costs and healthcare costs of five different prenatal screening strategies, using a virtual cohort of 652 653 pregnant women in France. Data were derived from the French Biomedicine Agency and published articles. Uncertainty was addressed using one-way sensitivity analysis. The five strategies compared were: (i) cfDNA testing for women with a risk following first-trimester screening of ≥ 1/250; (ii) cfDNA testing for women with a risk of ≥ 1/1000 (currently recommended); (iii) cfDNA testing in the general population (regardless of risk); (iv) invasive testing for women with a risk of ≥ 1/250 (historical strategy); and (v) invasive testing for women with a risk of ≥ 1/1000.

RESULTS

In our virtual population, at similar risk thresholds, cfDNA testing compared with invasive testing was cheaper but less effective. Compared with the historical strategy, cfDNA testing at the ≥ 1/1000 risk threshold was a more expensive strategy that detected 158 additional trisomies, but also 175 fewer other UBCA. Implementation of cfDNA testing in the general population would give an incremental cost-effectiveness ratio of €9 166 689 per additional anomaly detected compared with the historical strategy.

CONCLUSION

Extending cfDNA to lower risk thresholds or even to all pregnancies would detect more trisomies, but at greater expense and with lower detection rate of other UBCA, compared with the historical strategy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Cost-Effectiveness Analysis of Non-invasive Prenatal Testing for Down Syndrome in China

OBJECTIVES

There is little evidence in China regarding the cost-effectiveness of non-invasive prenatal testing (NIPT) for Down syndrome (DS). This study aims to evaluate the cost-effectiveness of NIPT and provide evidence to inform decision-making.

METHODS

To determine the cost-effectiveness of NIPT for DS, a decision-analytic model was developed using the TreeAge Pro software from a societal perspective in a simulated cohort of 10 000 pregnant women. Main indicators were based on field surveys from sampled hospitals in four locations in China and a literature review.

RESULTS

The conventional maternal serum screening (CMSS) strategy, contingent screening strategy (NIPT delivered to high risk pregnant women after CMSS), and universal screening strategy could prevent 3.02, 7.53, and 9.97 DS births, respectively. NIPT would decrease unnecessary invasive procedures, resulting in fewer procedure-related miscarriages. The cost-effectiveness ratio of the contingent screening strategy was the lowest. When compared with the CMSS strategy, the incremental cost per DS birth averted by the contingent screening strategy and universal screening strategy were USD 20,160 and 352,388, respectively. One-way sensitivity analysis showed that, if the cost of NIPT could be decreased to USD 76.92, the cost-effectiveness ratio of the universal screening strategy would be lower than the CMSS strategy.

CONCLUSIONS

Although NIPT has the merits of greater effectiveness and safety, CMSS is unlikely to be replaced by NIPT at this time because of NIPT's higher cost. Contingent screening may be an appropriate strategy to balance the effectiveness and cost factors of the new genetic testing technology.

The consequences of implementing non-invasive prenatal testing with cell-free foetal DNA for the detection of Down syndrome in the Spanish National Health Service: a cost-effectiveness analysis

Background

DNA-based non-invasive prenatal testing (NIPT) using maternal blood constitutes an emerging technology for the detection of Down syndrome (DS). The aim of the study was to conduct a cost-effectiveness analysis to evaluate the economic costs and health implications of the introduction of NIPT based on cell-free foetal DNA analysis through different screening strategies for the detection of DS.

Methods

An analytical short-term decision model was developed, from the payer´s perspective (Spanish National Health Service). The main outcome measure was the number of DS cases detected. Secondary measures included associated miscarriages, women undergoing current screening, women undergoing NIPT, positive NIPT and invasive procedures performed. The study setting was the Spanish National Health Service. Three strategies were compared: (a) first- and second-trimester screening (current screening); (b) NIPT as contingent testing; and (c) NIPT as first-line testing. Modelling was based on a hypothetical cohort of 100,000 Spanish pregnant women. Population data were obtained from the database of the Basque Antenatal Screening Programme. Deterministic sensitivity analyses were performed to assess variations in the cost of NIPT, screening risk cut-off, screening uptake-rate and rate of failure of NIPT.

Results

NIPT as contingent testing (strategy b) led to fewer miscarriages following invasive procedures and a slight reduction in the number of DS cases detected compared to current screening. However, lowering the screening cut-off to ≥ 1:500 would improve the overall effectiveness of NIPT as contingent testing, increasing the number of DS cases detected and decreasing foetal losses as compared to the current screening, despite there would be an extra-cost of 3.5%. When NIPT was used as first-line testing (strategy c), the screening would be more effective but also more expensive, with incremental cost-effectiveness ratios (ICERs) per additional case of DS detected of €1,299,763 and €1,232,763, compared with strategies a and b, respectively. Results were sensitive to the different parameters considered in the analysis.

Conclusions

Both, as first-line testing and as contingent testing when screening cut-off was lowered ≥ 1:500, NIPT would lead to more favourable outcomes as compared to the current screening (both in terms of DS cases detected and miscarriages avoided), but at a greater cost.

The importance of pre- and post-test counseling for prenatal cell-free DNA screening for common fetal aneuploidies

INTRODUCTION

Prenatal cell-free DNA screening for common fetal aneuploidies has rapidly changed the paradigm of prenatal care. Despite its advantages compared to conventional screening methods, its unexpectedly rapid implementation in clinical practice has generated several ethical and medical issues and misconceptions. Aggressive commercial marketing of cell-free DNA screening and media dissemination of misleading information have added confusion. Areas covered: This review provides an extensive update and will focus on the importance of pre-and post-test counseling for prenatal cell-free DNA screening not previously discussed extensively in the available literature. Additionally, we report cell-free DNA screening implementation in the largest obstetrical tertiary unit in Finland which is one of few countries that provides all prenatal screening methods free of charge for all women and has a very high uptake of first-trimester screening. This is not a systematical review, but rather a narrative overview which includes the most relevant and recent original publications and reviews covering this issue. Expert opinion: Despite being the most accurate method for screening of common fetal aneuploidies, the knowledge and counseling should be substantially improved. Cell-free DNA screening is not a replacement for diagnostic testing and its use in prenatal testing is complex and limited.

A contingent model for cell-free DNA testing to detect fetal aneuploidy after first trimester combined screening

Objective

To assess the results of the first trimester combined test to design a prenatal protocol for the introduction of the cell-free fetal DNA test as a contingent screening model.

Method

An observational retrospective study in 12,327 singleton pregnancies to analyze the results of the combined first trimester screening, the nuchal translucency ≥97.5 percentile, their cytogenetic results and birth outcomes.

Results

A total of 533 (4.3%) pregnant women had a risk in combined first trimester screening above 1/300. In this group, sixty nine had an unbalanced karyotype. The abnormal/normal karyotype ratio was 1/28 in pregnant women with intermediate risk (1/51-1/300) for trisomy 21 and trisomy 18, 1/58 with intermediate risk just for trisomy 21 and 1/37 with intermediate risk just for trisomy 18. A 19.8% of the unbalanced karyotypes had chromosomal abnormalities other than trisomies 21, 18 and 13. Two false negatives cases at first trimester combined screening presented a nuchal translucency ≥ p97.5^th.

Conclusion

We propose the introduction of the cell-free fetal DNA test when the risk of first trimester combined screening is intermediate (1/51–1/300) and when nuchal translucency is ≥ p97.5^th with a low risk in the combined screening. This policy would allow us to continue to detect uncommon chromosomal abnormalities.

Cost-effectiveness of cell-free DNA in maternal blood testing for prenatal detection of trisomy 21, 18 and 13: a systematic review

The aim of this paper was to conduct a systematic review of the cost-effectiveness of the analysis of cell-free DNA in maternal blood, often called the non-invasive prenatal test (NIPT), in the prenatal screening of trisomy in chromosomes 21, 18 and 13. MEDLINE, MEDLINE in process, EMBASE, and Cochrane Library were searched in April 2017. We selected: (1) economic evaluations that estimated the costs and detected cases of trisomy 21, 18 or 13; (2) comparisons of prenatal screening with NIPT (universal or contingent strategies) and the usual screening without NIPT, (3) in pregnant women with any risk of foetal anomalies. Studies were reviewed by two researchers. Data were extracted, the methodological quality was assessed and a narrative synthesis was prepared. In total, 12 studies were included, four of them performed in Europe. Three studies evaluated NIPT as a contingent test, three studies evaluated a universal NIPT, and six studies evaluated both. The results are heterogeneous, especially for the contingent NIPT where the results range from NIPT being dominant to a dominated strategy. Universal NIPT was found to be more effective but also costlier than the usual screening, with very high incremental cost-effectiveness ratios. One advantage of screening with NIPT is lower invasive procedure-related foetal losses than with usual screening. In conclusion, the cost-effectiveness of contingent NIPT is uncertain according to several studies, while the universal NIPT is not cost-effective currently.

Clinical and Economic Impact of Adopting Noninvasive Prenatal Testing as a Primary Screening Method for Fetal Aneuploidies in the General Pregnancy Population

OBJECTIVE

To evaluate the clinical and economic impact of adopting noninvasive prenatal testing (NIPT) using circulating cell-free DNA as a first-line screening method for trisomy 21, 18, and 13 in the general pregnancy population.

METHODS

A decision-analytical model was developed to assess the impact of adopting NIPT as a primary screening test compared to conventional screening methods. The model takes the Belgium perspective and includes only the direct medical cost of screening, diagnosis, and procedure-related complications. NIPT costs are EUR 260. Clinical outcomes and the cost per trisomy detected were assessed. Sensitivity analysis measured the impact of NIPT false-positive rate (FPR) on modelled results.

RESULTS

The cost per trisomy detected was EUR 63,016 for conventional screening versus EUR 66,633 for NIPT, with a difference of EUR 3,617. NIPT reduced unnecessary invasive tests by 94.8%, decreased procedure-related miscarriages by 90.8%, and increased trisomies detected by 29.1%. Increasing the FPR of NIPT (from < 0.01 to 1.0%) increased the average number of invasive procedures required to diagnose a trisomy from 2.2 to 4.5, respectively.

CONCLUSION

NIPT first-line screening at a reasonable cost is cost-effective and provides better clinical outcomes. However, modelled results are dependent on the adoption of an NIPT with a low FPR.

Cell-free DNA noninvasive prenatal screening for aneuploidy versus conventional screening: A systematic review of economic evaluations

Although noninvasive prenatal testing (NIPT) for aneuploidies using cell-free fetal DNA in maternal blood has been reported to have a high accuracy, only little evidence about its cost-effectiveness is available. We systematically reviewed and assessed quality of economic evaluation studies published between January 1, 2009 and January 1, 2016 where NIPT was compared to the current screening practices consisting of biochemical markers with or without nuchal translucency (NT) and/or maternal age. We included 16 studies and we found that, at current level of NIPT prices, contingent NIPT provide the best value for money, especially for publicly funded screening programs. NIPT as first-line test was found not cost-effective in the majority of studies. The NIPT unit cost, the risk cut-offs for current screening practice, the screening uptake rates (first- and second-line screening) as well as the costs and uptake rates of invasive diagnostic screening were the most common uncertain variables. The overall quality of included studies was fair. Considering a possible drop in prices and an ongoing NIPT expansion to include other chromosomes abnormalities other than T21, T18, T13 and sex chromosomes aneuploidies, future research are needed to examine the potential cost-effectiveness of implementing NIPT as first-line test.

Cell-Free DNA Screening: Complexities and Challenges of Clinical Implementation

Screening for fetal aneuploidy in pregnant women using cell-free DNA has increased dramatically since the technology became commercially available in 2011. Since that time, numerous trials have demonstrated high sensitivity and specificity to screen for common aneuploidies in high-risk populations. Studies assessing the performance of these tests in low-risk populations have also demonstrated improved detection rates compared with traditional, serum-based screening strategies. Concurrent with the increased use of this technology has been a decrease in invasive procedures (amniocentesis and chorionic villus sampling). As the technology becomes more widely understood, available, and utilized, challenges regarding its clinical implementation have become apparent. Some of these challenges include test failures, false-positive and false-negative results, limitations in positive predictive value in low-prevalence populations, and potential maternal health implications of abnormal results. In addition, commercial laboratories are expanding screening beyond common aneuploidies to include microdeletion screening and whole genome screening. This review article is intended to provide the practicing obstetrician with a summary of the complexities of cell-free DNA screening and the challenges of implementing it in the clinical setting.

Uptake, outcomes, and costs of implementing non-invasive prenatal testing for Down's syndrome into NHS maternity care: prospective cohort study in eight diverse maternity units

OBJECTIVE

 To investigate the benefits and costs of implementing non-invasive prenatal testing (NIPT) for Down's syndrome into the NHS maternity care pathway.

DESIGN

 Prospective cohort study.

SETTING

 Eight maternity units across the United Kingdom between 1 November 2013 and 28 February 2015.

PARTICIPANTS

 All pregnant women with a current Down's syndrome risk on screening of at least 1/1000.

MAIN OUTCOME MEASURES

 Outcomes were uptake of NIPT, number of cases of Down's syndrome detected, invasive tests performed, and miscarriages avoided. Pregnancy outcomes and costs associated with implementation of NIPT, compared with current screening, were determined using study data on NIPT uptake and invasive testing in combination with national datasets.

RESULTS

 NIPT was prospectively offered to 3175 pregnant women. In 934 women with a Down's syndrome risk greater than 1/150, 695 (74.4%) chose NIPT, 166 (17.8%) chose invasive testing, and 73 (7.8%) declined further testing. Of 2241 women with risks between 1/151 and 1/1000, 1799 (80.3%) chose NIPT. Of 71 pregnancies with a confirmed diagnosis of Down's syndrome, 13/42 (31%) with the diagnosis after NIPT and 2/29 (7%) after direct invasive testing continued, resulting in 12 live births. In an annual screening population of 698 500, offering NIPT as a contingent test to women with a Down's syndrome screening risk of at least 1/150 would increase detection by 195 (95% uncertainty interval -34 to 480) cases with 3368 (2279 to 4027) fewer invasive tests and 17 (7 to 30) fewer procedure related miscarriages, for a non-significant difference in total costs (£-46 000, £-1 802 000 to £2 661 000). The marginal cost of NIPT testing strategies versus current screening is very sensitive to NIPT costs; at a screening threshold of 1/150, NIPT would be cheaper than current screening if it cost less than £256. Lowering the risk threshold increases the number of Down's syndrome cases detected and overall costs, while maintaining the reduction in invasive tests and procedure related miscarriages.

CONCLUSIONS

 Implementation of NIPT as a contingent test within a public sector Down's syndrome screening programme can improve quality of care, choices for women, and overall performance within the current budget. As some women use NIPT for information only, the Down's syndrome live birth rate may not change significantly. Future research should consider NIPT uptake and informed decision making outside of a research setting.

"I think we've got too many tests!": Prenatal providers' reflections on ethical and clinical challenges in the practice integration of cell-free DNA screening

BACKGROUND

The recent introduction of cell-free DNA-based non-invasive prenatal screening (cfDNA screening) into clinical practice was expected to revolutionize prenatal testing. cfDNA screening for fetal aneuploidy has demonstrated higher test sensitivity and specificity for some conditions than conventional serum screening and can be conducted early in the pregnancy. However, it is not clear whether and how clinical practices are assimilating this new type of testing into their informed consent and counselling processes. Since the introduction of cfDNA screening into practice in 2011, the uptake and scope have increased dramatically. Prenatal care providers are under pressure to stay up to date with rapidly changing cfDNA screening panels, manage increasing patient demands, and keep up with changing test costs, all while attempting to use the technology responsibly and ethically. While clinical literature on cfDNA screening has shown benefits for specific patient populations, it has also identified significant misunderstandings among providers and patients alike about the power of the technology. The unique features of cfDNA screening, in comparison to established prenatal testing technologies, have implications for informed decision-making and genetic counselling that must be addressed to ensure ethical practice.

OBJECTIVES

This study explored the experiences of prenatal care providers at the forefront of non-invasive genetic screening in the United States to understand how this testing changes the practice of prenatal medicine. We aimed to learn how the experience of providing and offering this testing differs from established prenatal testing methodologies. These differences may necessitate changes to patient education and consent procedures to maintain ethical practice.

METHODS

We used the online American Congress of Obstetricians and Gynecologists Physician Directory to identify a systematic sample of five prenatal care providers in each U.S. state and the District of Columbia. Beginning with the lowest zip code in each state, we took every fifth name from the directory, excluding providers who were retired, did not currently practice in the state in which they were listed, or were not involved in a prenatal specialty. After repeating this step twice and sending a total of 461 invitations, 37 providers expressed interest in participating, and we completed telephone interviews with 21 providers (4.6%). We developed a semi-structured interview guide including questions about providers' use of and attitudes toward cfDNA screening. A single interviewer conducted and audio-recorded all interviews by telephone, and the interviews lasted approximately 30 minutes each. We collaboratively developed a codebook through an iterative process of transcript review and code application, and a primary coder coded all transcripts.

RESULTS

Prenatal care providers have varying perspectives on the advantages of cfDNA screening and express a range of concerns regarding the implementation of cfDNA screening in practice. While providers agreed on several advantages of cfDNA, including increased accuracy, earlier return of results, and decreased risk of complications, many expressed concern that there is not enough time to adequately counsel and educate patients on their prenatal screening and testing options. Providers also agreed that demand for cfDNA screening has increased and expressed a desire for more information from professional societies, labs, and publications. Providers disagreed about the healthcare implications and future of cfDNA screening. Some providers anticipated that cfDNA screening would decrease healthcare costs when implemented widely and expressed optimism for expanded cfDNA screening panels. Others were concerned that cfDNA screening would increase costs over time and questioned whether the expansion to include microdeletions could be done ethically.

CONCLUSIONS

The perspectives and experiences of the providers in this study allow insight into the clinical benefit, burden on prenatal practice, and potential future of cfDNA screening in clinical practice. Given the likelihood that the scope and uptake of cfDNA screening will continue to increase, it is essential to consider how these changes will affect frontline prenatal care providers and, in turn, patients. Providers' requests for additional guidance and data as well as their concerns with the lack of time available to explain screening and testing options indicate significant potential issues with patient care. It is important to ensure that the clinical integration of cfDNA screening is managed responsibly and ethically before it expands further, exacerbating pre-existing issues. As prenatal screening evolves, so should informed consent and the resources available to women making decisions. The field must take steps to maximize the advantages of cfDNA screening and responsibly manage its ethical issues.

Non-invasive prenatal testing for fetal chromosome abnormalities: review of clinical and ethical issues

Genomics-based non-invasive prenatal screening using cell-free DNA (cfDNA screening) was proposed to reduce the number of invasive procedures in current prenatal diagnosis for fetal aneuploidies. We review here the clinical and ethical issues of cfDNA screening. To date, it is not clear how cfDNA screening is going to impact the performances of clinical prenatal diagnosis and how it could be incorporated in real life. The direct marketing to users may have facilitated the early introduction of cfDNA screening into clinical practice despite limited evidence-based independent research data supporting this rapid shift. There is a need to address the most important ethical, legal, and social issues before its implementation in a mass setting. Its introduction might worsen current tendencies to neglect the reproductive autonomy of pregnant women.

Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non-laboratory aspects such as information and counseling), education of professionals, systematic evaluation of all aspects of prenatal screening, development of better evaluation tools in the light of the aim of the practice, accountability to all stakeholders including children born from screened pregnancies and persons living with the conditions targeted in prenatal screening and promotion of equity of access.

An Economic Analysis of Cell-Free DNA Non-Invasive Prenatal Testing in the US General Pregnancy Population

OBJECTIVE

Analyze the economic value of replacing conventional fetal aneuploidy screening approaches with non-invasive prenatal testing (NIPT) in the general pregnancy population.

METHODS

Using decision-analysis modeling, we compared conventional screening to NIPT with cell-free DNA (cfDNA) analysis in the annual US pregnancy population. Sensitivity and specificity for fetal aneuploidies, trisomy 21, trisomy 18, trisomy 13, and monosomy X, were estimated using published data and modeling of both first- and second trimester screening. Costs were assigned for each prenatal test component and for an affected birth. The overall cost to the healthcare system considered screening costs, the number of aneuploid cases detected, invasive procedures performed, procedure-related euploid losses, and affected pregnancies averted. Sensitivity analyses evaluated the effect of variation in parameters. Costs were reported in 2014 US Dollars.

RESULTS

Replacing conventional screening with NIPT would reduce healthcare costs if it can be provided for $744 or less in the general pregnancy population. The most influential variables were timing of screening entry, screening costs, and pregnancy termination rates. Of the 13,176 affected pregnancies undergoing screening, NIPT detected 96.5% (12,717/13,176) of cases, compared with 85.9% (11,314/13,176) by conventional approaches. NIPT reduced invasive procedures by 60.0%, with NIPT and conventional methods resulting in 24,596 and 61,430 invasive procedures, respectively. The number of procedure-related euploid fetal losses was reduced by 73.5% (194/264) in the general screening population.

CONCLUSION

Based on our analysis, universal application of NIPT would increase fetal aneuploidy detection rates and can be economically justified. Offering this testing to all pregnant women is associated with substantial prenatal healthcare benefits.

A Cost-Effectiveness Analysis of First Trimester Non-Invasive Prenatal Screening for Fetal Trisomies in the United States

Background

Non-invasive prenatal testing (NIPT) is a relatively new technology for diagnosis of fetal aneuploidies. NIPT is more accurate than conventional maternal serum screening (MSS) but is also more costly. Contingent NIPT may provide a cost-effective alternative to universal NIPT screening. Contingent screening used a two-stage process in which risk is assessed by MSS in the first stage and, based on a risk cutoff, high-risk pregnancies are referred for NIPT. The objective of this study was to (1) determine the optimum MSS risk cutoff for contingent NIPT and (2) compare the cost effectiveness of optimized contingent NIPT to universal NIPT and conventional MSS.

Study Design

Decision-analytic model using micro-simulation and probabilistic sensitivity analysis. We evaluated cost effectiveness from three perspectives: societal, governmental, and payer.

Results

From a societal perspective, universal NIPT dominated both contingent NIPT and MSS. From a government and payer perspective, contingent NIPT dominated MSS. Compared to contingent NIPT, adopting a universal NIPT would cost $203,088 for each additional case detected from a government perspective and $263,922 for each additional case detected from a payer perspective.

Conclusions

From a societal perspective, universal NIPT is a cost-effective alternative to MSS and contingent NIPT. When viewed from narrower perspectives, contingent NIPT is less costly than universal NIPT and provides a cost-effective alternative to MSS.

Prenatal screening for fetal aneuploidies with cell-free DNA in the general pregnancy population: a cost-effectiveness analysis

Objective: To estimate the cost-effectiveness of fetal aneuploidy screening in the general pregnancy population using non-invasive prenatal testing (NIPT) as compared to first trimester combined screening (FTS) with serum markers and NT ultrasound.

Methods: Using a decision-analytic model, we estimated the number of fetal T21, T18, and T13 cases identified prenatally, the number of invasive procedures performed, corresponding normal fetus losses, and costs of screening using FTS or NIPT with cell-free DNA (cfDNA). Modeling was based on a 4 million pregnant women cohort, which represents annual births in the U.S.

Results: For the general pregnancy population, NIPT identified 15% more trisomy cases, reduced invasive procedures by 88%, and reduced iatrogenic fetal loss by 94% as compared to FTS. The cost per trisomy case identified with FTS was $497 909. At a NIPT unit, cost of $453 and below, there were cost savings as compared to FTS. Accounting for additional trisomy cases identified by NIPT, a NIPT unit cost of $665 provided the same per trisomy cost as that of FTS.

Conclusions: NIPT in the general pregnancy population leads to more prenatal identification of fetal trisomy cases as compared to FTS and is more economical at a NIPT unit cost of $453.