Methodological limitations of economic evaluations of antenatal screening

A Systematic Review of Methods and Practice for Integrating Maternal, Fetal, and Child Health Outcomes, and Family Spillover Effects into Cost-Utility Analyses

BACKGROUND

Maternal-perinatal interventions delivered during pregnancy or childbirth have unique characteristics that impact the health-related quality of life (HRQoL) of the mother, fetus, and newborn child. However, maternal-perinatal cost-utility analyses (CUAs) often only consider either maternal or child health outcomes. Challenges include, but are not limited to, measuring fetal, newborn, and infant health outcomes, and assessing their impact on maternal HRQoL. It is also important to recognize the impact of maternal-perinatal health on family members' HRQoL (i.e., family spillover effects) and to incorporate these effects in maternal-perinatal CUAs.

OBJECTIVE

The aim was to systematically review the methods used to include health outcomes of pregnant women, fetuses, and children and to incorporate family spillover effects in maternal-perinatal CUAs.

METHODS

A literature search was conducted in Medline, Embase, EconLit, Cochrane Collection, Cumulative Index to Nursing and Allied Health Literature (CINAHL), International Network of Agencies for Health Technology Assessment (INAHTA), and the Pediatric Economic Database Evaluation (PEDE) databases from inception to 2020 to identify maternal-perinatal CUAs that included health outcomes for pregnant women, fetuses, and/or children. The search was updated to December 2022 using PEDE. Data describing how the health outcomes of mothers, fetuses, and children were measured, incorporated, and reported along with the data on family spillover effects were extracted.

RESULTS

Out of 174 maternal-perinatal CUAs identified, 62 considered the health outcomes of pregnant women, and children. Among the 54 quality-adjusted life year (QALY)-based CUAs, 12 included fetal health outcomes, the impact of fetal loss on mothers' HRQoL, and the impact of neonatal demise on mothers' HRQoL. Four studies considered fetal health outcomes and the effects of fetal loss on mothers' HRQoL. One study included fetal health outcomes and the impact of neonatal demise on maternal HRQoL. Furthermore, six studies considered the impact of neonatal demise on maternal HRQoL, while four included fetal health outcomes. One study included the impact of fetal loss on maternal HRQoL. The remaining 26 only included the health outcomes of pregnant women and children. Among the eight disability-adjusted life year (DALY)-based CUAs, two measured fetal health outcomes. Out of 174 studies, only one study included family spillover effects. The most common measurement approach was to measure the health outcomes of pregnant women and children separately. Various approaches were used to assess fetal losses in terms of QALYs or DALYs and their impact on HRQoL of mothers. The most common integration approach was to sum the QALYs or DALYs for pregnant women and children. Most studies reported combined QALYs and incremental QALYs, or DALYs and incremental DALYs, at the family level for pregnant women and children.

CONCLUSIONS

Approximately one-third of maternal-perinatal CUAs included the health outcomes of pregnant women, fetuses, and/or children. Future CUAs of maternal-perinatal interventions, conducted from a societal perspective, should aim to incorporate health outcomes for mothers, fetuses, and children when appropriate. The various approaches used within these CUAs highlight the need for standardized measurement and integration methods, potentially leading to rigorous and standardized inclusion practices, providing higher-quality evidence to better inform decision-makers about the costs and benefits of maternal-perinatal interventions. Health Technology Assessment agencies may consider providing guidance for interventions affecting future lives in future updates.

Benefits and harms of antenatal and newborn screening programmes in health economic assessments: the VALENTIA systematic review and qualitative investigation

Background

Health economic assessments are used to determine whether the resources needed to generate net benefit from an antenatal or newborn screening programme, driven by multiple benefits and harms, are justifiable. It is not known what benefits and harms have been adopted by economic evaluations assessing these programmes and whether they omit benefits and harms considered important to relevant stakeholders.

Objectives

(1) To identify the benefits and harms adopted by health economic assessments in this area, and to assess how they have been measured and valued; (2) to identify attributes or relevance to stakeholders that ought to be considered in future economic assessments; and (3) to make recommendations about the benefits and harms that should be considered by these studies.

Design

Mixed methods combining systematic review and qualitative work.

Systematic review methods

We searched the published and grey literature from January 2000 to January 2021 using all major electronic databases. Economic evaluations of an antenatal or newborn screening programme in one or more Organisation for Economic Co-operation and Development countries were considered eligible. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards checklist. We identified benefits and harms using an integrative descriptive analysis and constructed a thematic framework.

Qualitative methods

We conducted a meta-ethnography of the existing literature on newborn screening experiences, a secondary analysis of existing individual interviews related to antenatal or newborn screening or living with screened-for conditions, and a thematic analysis of primary data collected with stakeholders about their experiences with screening.

Results

The literature searches identified 52,244 articles and reports, and 336 unique studies were included. Thematic framework resulted in seven themes: (1) diagnosis of screened for condition, (2) life-years and health status adjustments, (3) treatment, (4) long-term costs, (5) overdiagnosis, (6) pregnancy loss and (7) spillover effects on family members. Diagnosis of screened-for condition (115, 47.5%), life-years and health status adjustments (90, 37.2%) and treatment (88, 36.4%) accounted for most of the benefits and harms evaluating antenatal screening. The same themes accounted for most of the benefits and harms included in studies assessing newborn screening. Long-term costs, overdiagnosis and spillover effects tended to be ignored. The wide-reaching family implications of screening were considered important to stakeholders. We observed good overlap between the thematic framework and the qualitative evidence.

Limitations

Dual data extraction within the systematic literature review was not feasible due to the large number of studies included. It was difficult to recruit healthcare professionals in the stakeholder's interviews.

Conclusions

There is no consistency in the selection of benefits and harms used in health economic assessments in this area, suggesting that additional methods guidance is needed. Our proposed thematic framework can be used to guide the development of future health economic assessments evaluating antenatal and newborn screening programmes.

Study registration

This study is registered as PROSPERO CRD42020165236.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127489) and is published in full in Health Technology Assessment; Vol. 28, No. 25. See the NIHR Funding and Awards website for further award information.

Methods for evaluating the benefits and harms of antenatal and newborn screening programmes adopted by health economic assessments: protocol for a systematic review

INTRODUCTION

Complex organisational arrangements are required to deliver antenatal and newborn screening programmes. Decision-makers consider the benefits and harms of screening when reviewing the evidence about these programmes. Economic evaluations contribute one important part of this assessment process. However, it is not fully understood what approaches health economic assessments have adopted to measure and value benefits and harms. This study aims to systematically review and critique the published and grey literature on methods for identifying, measuring and valuing the benefits and harms of antenatal and newborn screening adopted by health economic assessments.

METHODS AND ANALYSIS

Nine bibliographic databases will be searched from 2000 onwards. These search strategies will be supplemented by manual reference searching of bibliographies, forward citation searching, contacts with experts, author searching and web searching for grey literature. Studies will be selected for review if they report health economic assessments of an antenatal or newborn screening programme. Assessments of title and abstracts and full reports will be undertaken independently with disagreements resolved through discussion. Data extraction will include fields to assess the reporting quality of the studies using the Consolidated Health Economic Evaluation Reporting Standards statement and a bespoke ancillary form to assess how benefits and harms have been accounted for.

ETHICS AND DISSEMINATION

This is an evidence synthesis review from already published materials and hence ethics committee approval or written informed consent will not be required. Our results will be disseminated by publishing in high-impact peer-review journals and presenting at relevant conferences.

PROSPERO REGISTRATION NUMBER

CRD42020165236.

Challenges in economic evaluations in obstetric care: a scoping review and expert opinion

OBJECTIVE

The aim of this study is to identify items of economic evaluation guidelines that are frequently not complied within obstetric economic evaluations and to search for reasons for non-adherence.

DESIGN

Scoping review and qualitative study.

SETTING

Literature on economic evaluations in obstetric care and interviews with experts.

POPULATION OR SAMPLE

The sample included 229 scientific articles and five experts.

METHODS

A systematic literature search was performed. All types of literature about economic evaluations in obstetric care were included. The adherence to guidelines was assessed and articles were qualitatively analysed on additional information about reasons for non-adherence. Issues that arose from the scoping review were discussed with experts.

MAIN OUTCOME MEASURES

Adherence to guideline items of the included economic evaluations studies. Analytical themes describing reasons for non-adherence, resulting from qualitative analysis of articles and interviews with experts.

RESULTS

A total of 184 economic evaluations and 45 other type of articles were included. Guideline items frequently not complied with were time horizon, type of economic evaluation and effect measure. Reasons for non-adherence had to do with paucity of long-term health data and assessing and combining outcomes for mother and child resulting from obstetric interventions.

CONCLUSIONS

This study identified items of guidelines that are frequently not complied with and the reasons behind this. The results are a starting point for a broad consensus building on how to deal with these challenges that can result in special guidance for the conduct of economic evaluations in obstetric care.

TWEETABLE ABSTRACT

Non-adherence to guidelines in obstetric economic evaluation studies: the difficulties in detail.

An economic analysis of chromosome testing in couples with children who have structural chromosome abnormalities

Background

Structural chromosome abnormalities can cause significant negative reproductive outcomes as they typically result in morbidity and mortality of newborns. The prevalence of structural chromosomal abnormalities in live births is at least 0.05%, of which many of them have parental origins. It is uncommon to predict structural chromosome abnormalities at birth in the first child but it is possible to prevent repeated abnormalities through screening and diagnostic programmes. This study will provide an economic analysis of the prenatal detection of these abnormalities.

Methods

A cost-benefit analysis using a decision analytic model was employed to compare the status quo (doing nothing) with two interventional strategies. The first strategy (Strategy I) is preconceptional screening plus amniocentesis, and the second strategy (Strategy II) is amniocentesis alone. The monetary values in Thai baht (THB) were adjusted to international dollars (I$) using purchasing power parity (PPP) (I$1 = THB 17.60 for the year 2013). The robustness of the results was tested by applying a probabilistic sensitivity analysis.

Results

Both diagnostic strategies can reduce approximately 10.7–11.1 births with abnormal chromosomes per 1,000 diagnosed couples. The benefit cost ratios were 1.62 for Strategy I and 1.24 for Strategy II. Net present values per 1,000 diagnoses in couples were I$464,000 for Strategy I and I$267,000 for Strategy II. The probabilistic sensitivity analysis suggested that the cost-benefit analysis was sufficiently robust, confirming that both strategies provided higher benefits than costs.

Conclusions

Since the benefits of both diagnostic strategies exceeded their costs, both strategies are economical–with Strategy I being more economically attractive. Strategy I is superior to Strategy II because it decreases the risk of normal children potentially dying from the amniocentesis process.

Evaluating Cost-effectiveness of Interventions That Affect Fertility and Childbearing: How Health Effects Are Measured Matters

BACKGROUND

Current guidelines for economic evaluations of health interventions define relevant outcomes as those accruing to individuals receiving interventions. Little consensus exists on counting health impacts on current and future fertility and childbearing. Our objective was to characterize current practices for counting such health outcomes.

METHODS

We developed a framework characterizing health interventions with direct and/or indirect effects on fertility and childbearing and how such outcomes are reported. We identified interventions spanning the framework and performed a targeted literature review for economic evaluations of these interventions. For each article, we characterized how the potential health outcomes from each intervention were considered, focusing on quality-adjusted life-years (QALYs) associated with fertility and childbearing.

RESULTS

We reviewed 108 studies, identifying 7 themes: 1) Studies were heterogeneous in reporting outcomes. 2) Studies often selected outcomes for inclusion that tend to bias toward finding the intervention to be cost-effective. 3) Studies often avoided the challenges of assigning QALYs for pregnancy and fertility by instead considering cost per intermediate outcome. 4) Even for the same intervention, studies took heterogeneous approaches to outcome evaluation. 5) Studies used multiple, competing rationales for whether and how to include fertility-related QALYs and whose QALYs to include. 6) Studies examining interventions with indirect effects on fertility typically ignored such QALYs. 7) Even recent studies had these shortcomings. Limitations include that the review was targeted rather than systematic.

CONCLUSIONS

Economic evaluations inconsistently consider QALYs from current and future fertility and childbearing in ways that frequently appear biased toward the interventions considered. As the Panel on Cost-Effectiveness in Health and Medicine updates its guidelines, making the practice of cost-effectiveness analysis more consistent is a priority. Our study contributes to harmonizing methods in this respect.

Introducing the non-invasive prenatal test for trisomy 21 in Belgium: a cost-consequences analysis

BACKGROUND

The first- and second-trimester screening for trisomy 21 (T21) are reimbursed for all pregnant women in Belgium. Using a cut-off risk of 1:300 for T21, about 5% of all pregnant women are referred for definitive prenatal diagnosis using an invasive test, at a sensitivity of (only) 72.5%. The sensitivity and specificity of the non-invasive prenatal test (NIPT) are over 99% but come at a cost of €460 (£373) per test. The objective is to estimate the consequences of introducing NIPT for the detection of T21.

METHODS

A cost-consequences analysis was performed presenting the impact on benefits, harms and costs. Context-specific real-world information was available to set up a model reflecting the current screening situation in Belgium. This model was used to construct the second and first line NIPT screening scenarios applying information from the literature on NIPT's test accuracy.

RESULTS

Introducing NIPT in the first or second line reduces harm by decreasing the number of procedure-related miscarriages after invasive testing. In contrast with NIPT in the second line, offering NIPT in the first line additionally will miss fewer cases of T21 due to less false-negative test results. The introduction of NIPT in the second line results in cost savings, which is not true for NIPT at the current price in the first line. If NIPT is offered to all pregnant women, the price should be lowered to about €150 to keep the screening cost per T21 diagnosis constant.

CONCLUSIONS

In Belgium, the introduction and reimbursement of NIPT as a second line triage test significantly reduces procedure-related miscarriages without increasing the short-term screening costs. Offering and reimbursing NIPT in the first line to all pregnant women is preferred in the long term, as it would, in addition, miss fewer cases of T21. However, taking into account the government's limited resources for universal reimbursement, the price of NIPT should first be lowered substantially before this can be realised.

Economic evaluation of multiplex ligation-dependent probe amplification and karyotyping in prenatal diagnosis: a cost-minimization analysis

Purpose

To assess the cost-effectiveness of Multiplex Ligation-dependent Probe Amplification (MLPA, P095 kit) compared to karyotyping.

Methods

A cost-minimization analysis alongside a nationwide prospective clinical study of 4,585 women undergoing amniocentesis on behalf of their age (≥36 years), an increased risk following first trimester prenatal screening or parental anxiety.

Results

Diagnostic accuracy of MLPA (P095 kit) was comparable to karyotyping (1.0 95% CI 0.999–1.0). Health-related quality of life did not differ between the strategies (summary physical health: mean difference 0.31, p = 0.82; summary mental health: mean difference 1.91, p = 0.22). Short-term costs were lower for MLPA: mean difference €315.68 (bootstrap 95% CI €315.63–315.74; −44.4%). The long-term costs were slightly higher for MLPA: mean difference €76.42 (bootstrap 95% CI €71.32–81.52; +8.6%). Total costs were on average €240.13 (bootstrap 95% CI €235.02–245.23; −14.9%) lower in favor of MLPA. Cost differences were sensitive to proportion of terminated pregnancies, sample throughput, individual choice and performance of tests in one laboratory, but not to failure rate or the exclusion of polluted samples.

Conclusion

From an economic perspective, MLPA is the preferred prenatal diagnostic strategy in women who undergo amniocentesis on behalf of their age, following prenatal screening or parental anxiety.

Electronic supplementary material

The online version of this article (doi:10.1007/s00404-011-1921-y) contains supplementary material, which is available to authorized users.

Viruses and other infections in stillbirth: what is the evidence and what should we be doing?

In Australia, as in other developed countries, approximately 40-50% of stillbirths are of unknown aetiology. Emerging evidence suggests stillbirths are often multifactorial. The absence of a known cause leads to uncertainty regarding the risk of recurrence, which can cause extreme anguish for parents that may manifest as guilt, anger or bewilderment. Further, clinical endeavours to prevent recurrences in future pregnancies are impaired by lack of a defined aetiology. Therefore, efforts to provide an aetiological diagnosis of stillbirth impact upon all aspects of care of the mother, and inform many parts of clinical decision making. Despite the magnitude of the problem, that is 7 stillbirths per 1000 births in Australia, diagnostic efforts to discover viral aetiologies are often minimal. Viruses and other difficult to culture organisms have been postulated as the aetiology of a number of obstetric and paediatric conditions of unknown cause, including stillbirth. Reasons forwarded for testing stillbirth cases for infectious agents are non-medical factors, including addressing all parents' need for diagnostic closure, identifying infectious agents as a sporadic cause of stillbirth to reassure parents and clinicians regarding risk for future pregnancies, and to reduce unnecessary testing. It is clear that viral agents including rubella, human cytomegalovirus (CMV), parvovirus B19, herpes simplex virus (HSV), lymphocytic choriomeningitis virus (LCMV), and varicella zoster virus (VZV) may cause intrauterine deaths. Evidence for many other agents is that minimal or asymptomatic infections also occur, so improved markers of adverse outcomes are needed. The role of other viruses and difficult-to-culture organisms in stillbirth is uncertain, and needs more research. However, testing stillborn babies for some viral agents remains a useful adjunct to histopathological and other examinations at autopsy. Modern molecular techniques such as multiplex PCR, allow searches for multiple agents. Now that such testing is available, it is important to assess the clinical usefulness of such testing.

Misconstructions in health economics applied to the evaluation of prenatal screening

The application of economic evaluation to prenatal screening has led to ethical debates about the joint risks of rationing and eugenics. These debates have chosen the wrong target, as economic evaluations espouse the hypotheses and value judgment of their commissioners. This paper explores the difficulties in interpreting and using the results of economic evaluations. The first set of difficulties concerns the diversity in end points and the lack of an aggregate end point to reflect a generally desirable outcome. Another set results from the wider societal implications of economic evaluations and the implicit value judgments. Misunderstandings of the methods used for the economic evaluation of prenatal screening result from the lack of clearly stated objectives from policy makers.

Cost utility of prenatal diagnosis and the risk-based threshold

BACKGROUND

Prenatal testing guidelines recommend offering amniocentesis or chorionic villus sampling to women aged 35 years or older, or who have been found by screening to be at a similarly high risk of giving birth to an infant with Down's syndrome or another chromosomal abnormality. This threshold was chosen, in part, because 35 was the approximate age at which amniocentesis was cost beneficial when testing guidelines were developed in the USA in the 1970s. We aimed to assess the economic validity of thresholds based on age or risk for offering invasive prenatal diagnosis.

METHODS

We did a cost-utility analysis of chorionic villus sampling and amniocentesis versus no invasive testing using data from randomised trials, case registries, and a utility assessment of 534 diverse pregnant women aged 16-47 years.

FINDINGS

In the USA, compared with no diagnostic testing, amniocentesis costs less than US15000 dollars per quality-adjusted life year gained for women of all ages and risk levels. The results do not depend on maternal age or risk of Down's syndrome-affected birth. The cost-utility ratio for any individual woman depends on her preferences for reassurance about the chromosomal status of her fetus, and, to a lesser extent, for miscarriage.

INTERPRETATION

Prenatal diagnostic testing can be cost effective at any age or risk level. Current guidelines should be changed to offer testing to all pregnant women, not just those whose risk of carrying an affected fetus exceeds a specified threshold.

Preference-based approaches to measuring the benefits of perinatal care

Studies that measure benefits of health care interventions in natural or physical units cannot incorporate the several health changes that might occur within a single measure, and they overlook individuals' preferences for those health changes. This paper discusses and critically appraises the application of preference-based approaches to the measurement of the benefits of perinatal care that have developed out of economic theory. These include quality adjusted life year (QALY)-based approaches, monetary-based approaches, and discrete choice experiments. QALY-based approaches use scaling techniques, such as the rating scale, standard gamble approach, and time trade-off approach, or multi-attribute utility measures, to measure the health-related quality of life weights of health states. Monetary-based approaches include the revealed preference approach, which involves observing decisions that individuals actually make concerning health risks, and the willingness-to-pay approach, which provides a framework for investigating individuals' willingness to pay for benefits of health care interventions. Discrete choice experiments describe health care interventions in terms of their attributes, and elicit preferences for scenarios that combine different levels of those attributes. Empirical examples are used to illustrate each preference-based approach to benefit measurement, and several methodological issues raised by the application of these approaches to the perinatal context are discussed. Particular attention is given to identifying the relevant attributes to incorporate into the measurement instrument, appropriate respondents for the measurement exercise, potential sources of bias in description and valuation processes, and the practicality, reliability, and validity of alternative measurement approaches. The paper's conclusion is that researchers should be explicit and rigorous in their application of preference-based approaches to benefit measurement in the context of perinatal care.