Economic analysis of prenatal screening strategies for Down syndrome in singleton pregnancies in Turkey

Placental elasticity in trisomy 21: prenatal assessment with shear-wave elastography

OBJECTIVES

To quantitatively examine placental tissue elasticity in Trisomy 21 (T21) pregnancies using shear wave elastography (SWE) and to evaluate the potential contribution of placental SWE measurements in predicting T21 fetuses.

METHODS

This prospective case-control study was conducted at tertiary centers between January 2022 and January 2024. The study included 30 pregnant women who underwent invasive prenatal diagnostic testing and were found to have T21, along with 30 pregnant women with a normal karyotype. Central placental elasticity measurements were performed from the middle of the thickest part of the placenta, avoiding vascular areas and lacunae, and peripheral measurements were performed two centimeter (cm) medial to the lateral border of the placenta.

RESULTS

The mean gestational week at measurement was 16 ± 2 weeks. Peripheral placental SWE velocity was significantly higher in the T21 group (7.4 ± 3.7 kPa vs. 4.8 ± 3.6 kPa, p=0.004). Similarly, central placental SWE velocity was also significantly higher in the T21 group (6.5 ± 2.1 kPa vs. 4.1 ± 2.6 kPa, p<0.001). In predicting T21, central placental SWE velocity had 76.7 % sensitivity and 73.3 % specificity with a cut-off value of ≥4.35 kPa (p<0.001), and peripheral had 70 % sensitivity and 66.7 % specificity with a cut-off value of ≥4.65 kPa (p=0.004). When central placental SWE velocity was ≥4.35 kPa, the risk of T21 was increased 6.64-fold, even after adjusting for maternal age, which is a well-known risk factor for T21.

CONCLUSIONS

Placental stiffness was significantly higher in T21 in both central and peripheral areas. Placental elasticity, especially in the central part, may be a potential marker for T21.

Impact of Structural Differences on the Modeled Cost-Effectiveness of Noninvasive Prenatal Testing

BACKGROUND

Noninvasive prenatal testing (NIPT) was developed to improve the accuracy of prenatal screening to detect chromosomal abnormalities. Published economic analyses have yielded different incremental cost-effective ratios (ICERs), leading to conclusions of NIPT being dominant, cost-effective, and cost-ineffective. These analyses have used different model structures, and the extent to which these structural variations have contributed to differences in ICERs is unclear.

AIM

To assess the impact of different model structures on the cost-effectiveness of NIPT for the detection of trisomy 21 (T21; Down syndrome).

METHODS

A systematic review identified economic models comparing NIPT to conventional screening. The key variations in identified model structures were the number of health states and modeling approach. New models with different structures were developed in TreeAge and populated with consistent parameters to enable a comparison of the impact of selected structural variations on results.

RESULTS

The review identified 34 economic models. Based on these findings, demonstration models were developed: 1) a decision tree with 3 health states, 2) a decision tree with 5 health states, 3) a microsimulation with 3 health states, and 4) a microsimulation with 5 health states. The base-case ICER from each model was 1) USD$34,474 (2023)/quality-adjusted life-year (QALY), 2) USD$14,990 (2023)/QALY, (3) USD$54,983 (2023)/QALY, and (4) NIPT was dominated.

CONCLUSION

Model-structuring choices can have a large impact on the ICER and conclusions regarding cost-effectiveness, which may inadvertently affect policy decisions to support or not support funding for NIPT. The use of reference models could improve international consistency in health policy decision making for prenatal screening.

HIGHLIGHTS

NIPT is a clinical area in which a variety of modeling approaches have been published, with wide variation in reported cost-effectiveness.This study shows that when broader contextual factors are held constant, varying the model structure yields results that range from NIPT being less effective and more expensive than conventional screening (i.e., NIPT was dominated) through to NIPT being more effective and more expensive than conventional screening with an ICER of USD$54,983 (2023)/QALY.Model-structuring choices may inadvertently affect policy decisions to support or not support funding of NIPT. Reference models could improve international consistency in health policy decision making for prenatal screening.

Does health economics research align with the disease burden in the Middle East and North Africa region? A systematic review of economic evaluation studies on public health interventions

INTRODUCTION

Economic evaluation studies demonstrate the value of money in health interventions and enhance the efficiency of the healthcare system. Therefore, this study reviews published economic evaluation studies of public health interventions from 26 Middle East and North Africa (MENA) countries and examines whether they addressed the region's major health problems.

METHODS

PubMed and Scopus were utilized to search for relevant articles published up to June 26, 2021. The reviewers independently selected studies, extracted data, and assessed the quality of studies using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

RESULTS

The search identified 61 studies. Approximately half (28 studies; 46%) were conducted in Israel and Iran. The main areas of interest for economic evaluation studies were infectious diseases (21 studies; 34%), cancers (13 studies; 21%), and genetic disorders (nine studies; 15%). Five (8%), 39 (64%), 16 (26%), and one (2%) studies were classified as excellent, high, average, and poor quality, respectively. The mean of CHEERS checklist items reported was 80.8% (SD 14%). Reporting the structure and justification of the selected model was missed in 21 studies (37%), while price and conversion rates and the analytical methods were missed in 21 studies (34%).

CONCLUSIONS

The quantity of economic evaluation studies on public health interventions in the MENA region remains low; however, the overall quality is high to excellent. There were obvious geographic gaps across countries regarding the number and quality of studies and gaps within countries concerning disease prioritization. The observed research output, however, did not reflect current and upcoming disease burden and risk factors trends in the MENA region.

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.

Effect of antiepileptic drugs on serum biochemical marker levels of first and second trimester screening tests

OBJECTIVES

Our aim in this study was to evaluate the effect of antiepileptic drugs on biochemical components of screening tests.

MATERIALS AND METHODS

This longitudinal case-control study was performed at Ankara City Hospital, Ankara, Turkey, from June 2020 to January 2021. The case group included epileptic singleton pregnant women which were using antiepileptic drugs, between 18 and 44 years of age. The control group included healthy pregnant women between 18 and 44 years old who did not use any drugs. Maternal medical, obstetric, and gynecological history were recorded. The antiepileptic agents that are used in our study were; lamotrigine, levetiracetam, carbamazepine, oxcarbazepine, valproic acid, and clonazepam. For the aneuploidy screening program conducted in our laboratory, the biochemical markers that are analyzed include; free b-hCG and PAPP-A in the first trimester, as well as AFP, HCG, and unconjugated estriol (uE3) in the second trimester. MoM values of these markers were compared between the case and control groups.

RESULTS

Fifty-three pregnant women with epilepsy using antiepileptic drugs were compared with 106 healthy pregnant women. The levels of serum-free b-hCG, and PAPP-A were similar between the case and control groups (p = 0.653, p = 0.351). For the second-trimester screening biochemical markers, the maternal serum uE3 and AFP levels expressed as MoM were significantly higher in the epileptic group than in the control patients (p = 0.015 and p = 0.001).

CONCLUSION

Serum marker levels of second-trimester screening tests may be affected by antiepileptic drugs, which may lead to misinterpretation of the risk level. Antiepileptic drug usage should be considered when evaluating screening test results.

Out-of-pocket and private pay in clinical genetic testing: A scoping review

Full coverage of the cost of clinical genetic testing is not always available through public or private insurance programs, or a public healthcare system. Consequently, some patients may be faced with the decision of whether to finance testing out-of-pocket (OOP), meet OOP expenses required by their insurer, or not proceed with testing. A scoping review was conducted to identify literature associated with patient OOP and private pay in clinical genetic testing. Seven databases (EMBASE, MEDLINE, CINAHL, PsychINFO, PAIS, the Cochrane Database of Systematic Reviews, and the JBI Evidence-Based Practice database) were searched, resulting in 83 unique publications included in the review. The presented evidence includes a descriptive analysis, followed by a narrative account of the extracted data. Results were divided into four groups according to clinical indication: (1) hereditary breast and ovarian cancer, (2) other hereditary cancers, (3) prenatal testing, (4) other clinical indications. The majority of studies focused on hereditary cancer and prenatal genetic testing. Overall trends indicated that OOP costs have fallen and payer coverage has improved, but OOP expenses continue to present a barrier to patients who do not qualify for full coverage.

Effect of anti-epileptic drugs on first trimester screening test results

OBJECTIVE

To evaluate first trimester screening test parameters in epileptic patients using anti-epileptic drugs.

MATERIALS AND METHODS

We retrospectively evaluated first trimester screening test results of 23 epileptic pregnant women using anti-epileptic drugs with a control group consisting of 92 healthy pregnancies. The anti-epileptic drugs used in this study were carbamazepine, levatiracetam, valproic acid and lamotrigine. Single drug or multi-drug regimens were used according to the clinical conditions. Patients with any known chronic or acute disease and drug usage were excluded from the study. Comparisons were performed via Mann-Whitney U test.

RESULTS

First trimester screening test biochemical markers were compared and maternal serum PAPP-A MoM values were found to be similar in study and control groups while β-hCG MoM values were significantly higher in pregnancies using epileptic drugs (p: 0,737 and p < 0.001, respectively).

CONCLUSION

Biochemical first trimester screening test results may be affected by anti-epileptic drug usage, which may lead to misinterpretation of the risk level. Thus, validation of MoM values should be necessary in order to obtain optimal results.

Detection of chromosome abnormalities using current noninvasive prenatal testing: A multi-center comparative study

Noninvasive prenatal testing (NIPT) is increasingly recognized and utilized in the antenatal care field. In the current study, we aimed to evaluate the clinical application and compare test outcomes of two generations of currently used NIPT techniques for detecting fetal chromosome abnormalities in a high-risk prenatal population. A total of 7,252 pregnant women were included from twenty-one hospitals from January 2015 to September 2017. A maternal blood sample of each participant was collected for fetal DNA sequencing. Group I received a first generation NIPT sequencing technique to detect chromosome aneuploidies, and Group II received a second generation NIPT sequencing technique to detect subchromosome abnormalities. An abnormal NIPT result was reported in 0.90% (44/4,868) of the women in Group I and 2.68% (64/2,384) in Group II. In Group I, seventeen (17/37, 45.95%) women with suspected fetal aneuploidy received amniocentesis, which confirmed 100% (10/10) of positive trisomy 21 samples, 100% (1/1) of trisomy 18, 100% (1/1) of sex chromosome abnormality, 0% (0/2) of trisomy 16, 0% (0/2) of trisomy 13, and 0% (0/1) of trisomy 20 and 13. In Group II, aneuploidy accounted for 46.88% (30/64) of the abnormal results. Five underwent amniocentesis and three had an abnormal result, including two cases of trisomy 21 and one case of chromosome 5p deletion syndrome. Whereas one case of 46,XN,del(16q11.2-q22.3) and another case of 46,XN,dup(Xp22.31) were considered as normal. NIPT is a quick and reliable screening method for detecting fetal chromosome aneuploidies and subchromosome deletions/duplications. Challenges remain for the comprehensive clinical application of NIPT.