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

ObjectiveTo evaluate the cost-effectiveness of high-throughput, non-invasive prenatal testing (HT-NIPT) for fetalRhesus D (RhD) genotype to guide antenatal prophylaxis with anti-D immunoglobulin compared with routine antenatal anti-D immunoglobulin prophylaxis (RAADP). DesignCost-effectiveness decision-analytic modelling. SettingPrimary care. ParticipantsA simulated population of 100000 RhD-negative women not known to be sensitised to the RhD antigen. MethodsA 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 bivariatemeta-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, whereas women with a negative result received none. Five alternative strategies in which the use of HT-NIPT may affect the existing postpartum care pathway were considered. Main outcome measuresCosts expressed in 2015GBP and impact on health outcomes expressed in terms of quality-adjusted life-years over a lifetime. ResultsThe results suggested that HT-NIPT appears cost saving but also less effective than current practice, irrespective of the postpartum strategy evaluated. A postpartum 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. ConclusionsHT-NIPT would reduce unnecessary treatment with routine anti-D immunoglobulin and is cost saving when compared with current practice. The extent of any savings and cost-effectiveness is sensitive to the overall test cost. Tweetable abstractHT-NIPT is cost saving compared with providing anti-D to all RhD-negative pregnant women. Tweetable abstract HT-NIPT is cost saving compared with providing anti-D to all RhD-negative pregnant women.