High-throughput, non-invasive prenatal testing for fetal RHD genotype to guide antenatal prophylaxis with anti-D immunoglobulin : a cost-effectiveness analysis

OBJECTIVE: To evaluate the cost-effectiveness of high-throughput, non-invasive prenatal testing (HT-NIPT) for fetal RhD genotype to guide antenatal prophylaxis with anti-D immunoglobulin compared to routine antenatal anti-D immunoglobulin prophylaxis (RAADP). DESIGN: Cost-effectiveness decision-analytic modelling. SETTING: Primary care. PARTICIPANTS: A simulated population of 100,000 RhD negative women not known to be sensitised to the RhD antigen. METHODS: A decision tree model was used to characterise the antenatal care pathway in England and the long-term consequences of sensitisation events. The diagnostic accuracy of HT-NIPT was derived from a systematic review and bivariate meta-analysis; estimates of other inputs were derived from relevant literature sources and databases. Women in whom the HT-NIPT was positive or inconclusive continued to receive RAADP, while women with a negative result received none. Five alternative strategies in which the use of HT-NIPT may affect the existing post-partum care pathway were considered. MAIN OUTCOME MEASURES: Costs expressed in 2015GBP and impact on health outcomes expressed in terms of quality adjusted life years (QALYs) over a lifetime. RESULTS: The results suggested that HT-NIPT appears cost saving but also less effective than current practice, irrespective of the post-partum strategy evaluated. A post-partum strategy in which inconclusive test results are distinguished from positive results performed best. HT-NIPT is only cost-effective when the overall test cost is £26.60 or less. CONCLUSIONS: HT-NIPT would reduce unnecessary treatment with routine anti-D immunoglobulin and is cost saving when compared to current practice. The extent of any savings and cost-effectiveness is sensitive to the overall test cost. This article is protected by copyright. All rights reserved.