Do hospitals taking part in the trial need to manage labour in the same way?
In a large trial involving hundreds of hospitals internationally it is inevitable that there will be some differences in the management of labour between hospitals. However, these will not bias the trial results. Providing that the trial is large enough, randomisation will ensure that the intervention and control groups are identical with regard to both known and unknown confounders. It is possible that the size of the intervention effect may vary a little bit depending on the type of management given; information will be collected on key aspects of patient management. Nevertheless, any differences would not affect the direction of the treatment effects. Patients in the future will almost certainly receive different forms of care than they do today. Treatments shown to be effective today may be more or less effective in the future, but the direction of the effect will be the same. Rather than standardise patient management, it is more important that the trials are large enough and the
