Cost and resource implications with serum angiogenic factor estimation in the triage of pre-eclampsia

Objectives To analyse the economic and resource implications of using plasma soluble fms-like tyrosine kinase-1 s(Flt1) and placenta growth factor (PlGF) measurements in pre-eclampsia evaluation and management. Design Retrospective cost analysis of our prospective cohort study. Setting Boston, Massachusetts (USA). Population Women (n = 176) presenting to the hospital at < 34 weeks of gestation for evaluation of possible pre-eclampsia during 2009-10. Cases without complete cost or outcome data (n = 9) and re-enrolments (n = 18) were excluded. Methods Modelled comparisons between the standard approach (combination of blood pressure, urinary protein excretion, alanine aminotransferase and platelet counts) and a novel approach (ratio of plasma sFlt1 and PlGF) using actual hospital data converted to 2012 US dollars in accordance with the Centers for Medicare and Medicaid Services. Main outcome measures Direct 2-week costs and resource use by groups having true or false positive and negative test results for adverse outcomes according to approach. Results The improved specificity of the novel approach decreased the proportion of women falsely labelled as test-positive from 42.3% (34.4-50.2%) to 4.0% (0.85-7.15%) and increased the proportion correctly labelled as test-negative from 23.5% (16.730.3%) to 61.7% (53.9-69.5%). This could potentially reduce average per-patient costs by $ 1215. Substantial quantities of resources [47.2% (35.7-58.7%) of antenatal admissions and 72.5% (68.0-77.0%) of tests for fetal wellbeing] were unnecessarily used for women who were truly negative. A proportion of iatrogenic preterm deliveries among women with negative results was potentially avoidable representing further cost and resource savings. Conclusions Clinical use of the plasma sFlt1 and PlGF ratio improves risk stratification among women presenting for preeclampsia evaluation and has the potential to reduce costs and resource use.