Economic evaluation in implementation science: A reconciled approach evaluating programmes to increase the uptake of magnesium sulphate in pre-term births

Abstract

Abstract Background: Methods for the economic evaluation of implementation initiatives to increase the uptake of cost-effective healthcare interventions are not standardised. Value of implementation and policy cost-effectiveness are two proposed approaches. This research aims to compare these two methods and propose a standardised approach. To illustrate this, we evaluated two implementation programmes to increase magnesium sulphate (MgSO4) uptake in preterm labour to reduce the risk of cerebral palsy: i) the National PReCePT Programme (NPP) which provided regional support and funded clinical time in maternity units in England, and ii) an enhanced support programme (ESP) with additional unit-level coaching and extra funded time, which was nested within NPP and subject to a cluster RCT. Methods: After summarising value of implementation and policy cost-effectiveness methods, we explored the extent to which the two methods can be viewed as mathematically equivalent for the purpose of evaluating the NPP (versus pre-existing trends) and the ESP (versus the NPP) calculating their incremental cost-effectiveness ratios, net monetary benefits, and their probability of being cost-effective. Results: We demonstrate that value of implementation and policy cost-effectiveness methods can be expressed in mathematically equivalent terms and propose a standardised stepwise approach. Both methods depend on the change in the uptake of the healthcare technology, cost of the implementation activity, size of the eligible population affected over time, and the cost-effectiveness of the healthcare technology. We illustrated our standardised approach in two economic evaluations: the NPP generated a societal lifetime net monetary benefit of £30,247 per maternity unit over 12 months, at a willingness-to-pay threshold of £20,000; the probability of being cost-effective was 98%. In contrast, the ESP generated a net monetary benefit of -£28,682 per maternity unit in comparison to the NPP; the probability of being cost-effective was 22%. Conclusions: Policy cost-effectiveness and value of implementation approaches can be represented by a standardised stepwise method for the economic evaluation of implementation initiatives. Our illustrative examples show how the value of different quality improvement interventions for the same cost-effective treatment can be evaluated and compared. Our standardised method may facilitate a more systematic assessment of the value for money of implementation initiatives, which should be viewed as an important component of implementation research.