INTRODUCTION
Assisted vaginal birth (AVB) is an invasive procedure that, in skilled hands, can markedly improve maternal and neonatal outcomes arising from complications in the second stage of labour. Typically, AVB involves the use of devices such as forceps or ventouse and, more recently, new devices. Well-designed randomised controlled trials (RCTs) are essential for assessing the effectiveness of invasive procedures such as AVB, thereby enabling clinicians to make evidence-based decisions about whether to introduce them in routine practice. Similarly, high-quality reporting of RCTs is necessary to ensure that such procedures and devices are adopted and implemented correctly. However, the design and conduct of RCTs involving invasive procedures and devices (such as AVB) can be challenging because of their complexity. Complex interventions are defined as those with multiple interacting components that can act independently or interdependently to influence outcomes. This complexity can create difficulties in establishing how interventions should be delivered (standardisation) and ascertaining whether they are actually delivered as intended (adherence) within an RCT. Additional challenges are that the delivery of complex interventions can be influenced by clinicians’ skill (expertise). There may also be repeated modifications of new invasive procedures or devices during the developmental phase, which may not be reported or accounted for in trial design, that may influence trial outomes.
With accumulating numbers of reports citing complications associated with new invasive procedures and devices, expert panels have suggested that more rigorous clinical evaluation is required through improved RCT design. The need for methodological rigour has also been acknowledged in reporting guidance documents such as the Consolidating Standards of Reporting Trials extension for non-pharmacological treatments (CONSORT-NPT), which includes invasive procedures and devices such as those used for AVB. CONSORT-NPT suggests that ‘precise details of the experimental treatment’, ‘details on whether and how the interventions were standardised’, ‘details of whether and how adherence of care providers to the protocol was assessed’, and ‘information about the expertise of care providers’ should all be described in trial reports. As well as reducing bias and improving methodological quality, provision of this information should help to contextualise trial findings, enable successful interventions to be replicated in practice, and reduce research waste.
The aim of this review was to assess the reporting standards in RCTs of AVB according to CONSORT-NPT guidance, specifically focusing on intervention description, standardisation, adherence and clinician expertise.