Cost-effectiveness of antenatal screening for pre-eclampsia using PlGF and sFlt-1/PlGF ratio in Tanzania: A pre-trial health economic modelling study

Pre-eclampsia (PE) is a major contributor to maternal and neonatal morbidity and mortality. Research in high-income countries has shown that biomarker-based PE screening can improve timely detection and management of women at high risk of PE. We conducted a pre-trail cost-effectiveness analysis of introducing biomarker screening in Tanzania to identify key parameters informing a full, trial-based economic evaluation. We developed a decision tree comparing current practice with two biomarker-based screening strategies: Strategy 1 introducing placental growth factor (PlGF), and Strategy 2 adding soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio. Under both strategies we assumed early aspirin prophylaxis and/or close monitoring for high-risk women. For each of the three options, we modelled PE diagnosis, as well as maternal and neonatal outcomes over a one-year time horizon, assuming a healthcare sector perspective. We quantified health outcomes in terms of disability-adjusted life years (DALYs) and costs in 2023 US$. When compared to current practice, the incremental cost per DALY averted was $410.45 for Strategy 1 and $1,011.78 for Strategy 2. Limiting the novel strategies to nulliparous women, decreased incremental cost-effectiveness ratios to $184.15 (Strategy 1) and $413.33 (Strategy 2). Key parameters impacting cost-effectiveness were PE prevalence, biomarker screening accuracy, adherence to and effectiveness of preventive treatment and monitoring, and related costs. Based on our findings, biomarker screening has the potential to be cost-effective in Tanzania, particularly if introduced early in pregnancy and targeted at nulliparous women. Further research in low-resource settings is needed to overcome the current data and evidence gaps.