Demonstrating the value for money of implementing evidence-based treatment: the case for further investment in magnesium sulphate as a neuroprotectant for preterm births

Carlos Sillero-Rejon^1,2*Hannah B Edwards^1,2Brent C Opmeer^2,3William Hollingworth^1,2Christalla Pithara-Mckeown^1,2Frank de Vocht^1,2Sabi Redwood^1,2David Odd^4,5Karen Luyt^1,2Hugh Mcleod^1,2

• ¹University of Bristol, Bristol, United Kingdom
• ²NIHR Applied Research Collaboration West, Bristol, United Kingdom
• ³Vilans, Utrecht, Netherlands
• ⁴Cardiff University, Cardiff, United Kingdom
• ⁵NHS Wales Cardiff and Vale University Health Board, Cardiff, United Kingdom

Background: Effective and cost-effective treatments are not always optimally implemented. The benefit forgone due to sub-optimal implementation is often not considered or estimated. We use the economic concept of 'incremental net monetary benefit' (INMB) to demonstrate how this can be valued. This approach can inform decision-making when used to estimate the value for money of potential future quality improvement (QI) programmes. We illustrate these analyses using the case of antenatal magnesium sulphate (MgSO4), a cost-effective treatment for the prevention of cerebral palsy in preterm births. We estimate the optimal implementation of MgSO4, the INMB lost due to sub-optimal implementation, and the value of future implementation initiatives to increase the use of MgSO4. Methods: We estimated MgSO4 treatment implementation for babies under 32 weeks' gestation using routine data on its uptake between 2014 and 2022 in England, Scotland, and Wales. The optimal uptake level of MgSO4 was estimated using clinical judgment. The societal lifetime INMB of MgSO4 for the prevention of cerebral palsy in preterm births was obtained from the literature. The INMB of sub-optimal implementation over time was estimated as the difference between optimal and actual uptake over time in each country. We estimated the cost-effectiveness of a hypothetical future QI programme based on different scenarios of implementation effectiveness and costs. Results: The optimal uptake of MgSO4 was 95%. The INMB forgone associated with sub-optimal MgSO4 uptake has reduced over time, as uptake has increased. However, in 2022, the societal lifetime INMB forgone was still £18.2m in England, £3.7m in Scotland, and £1.0m in Wales. A future QI programme across all three countries achieving a 5% increase in MgSO4 uptake over one year, and costing £987,500 to implement, would be cost-effective; generating £7.5m in INMB. Future implementation initiatives are likely to be cost-effective within a range of different implementation effectiveness and costs. Conclusions: The case of MgSO4 treatment for preterm birth illustrates how sub-optimal implementation of evidence-based interventions can be associated with high opportunity costs measured as INMB forgone. This approach provides valuable quantification of the value for money of future QI programmes to improve the implementation of these interventions.