Net benefit

In order to evaluate the potential clinical value of using the risk prediction model to inform decision-making, we performed net benefit analyses (which was not prespecified), where benefits and harms of a risk prediction model are put on the same scale to allow direct comparison [28]. We plotted the standardised net benefit across a range of predicted risks of preterm birth within 7 days (0% to 20%). For the purpose of this analysis, we assumed that the standard of care for this population with signs and symptoms of preterm labour was to “treat” (e.g., admit to an appropriate hospital, give antenatal corticosteroids and magnesium sulphate) and that a percentage predicted risk of preterm birth would be used for “ruling out” treatment.