Intervention description (CONSORT-NPT items 5 and 5a)
Reporting of details about the interventions was assessed by recording verbatim descriptions of the operative components and steps of the procedure (item 5a). A description was deemed to have been provided if anything more than the name of the intervention or device was reported. For example, a study reporting that ‘women had their birth assisted using forceps’ would not constitute a description, whereas information about how to apply the device to the fetal head would be considered as a description of the intervention. Although CONSORT-NPT requires ‘precise details’ of the intervention to be provided, this is not defined (item 5). Items 5 and 5a further stipulate the reporting of the‘sufficient details to allow replication’ and of ‘different components of the intervention’. We therefore defined ‘precise details’ of an intervention as provision of a description for each component of an AVB: device application, creation of a vacuum (ventouse only), device traction and device removal. Descriptions of co-interventions (defined as ‘naturally accompanying or associated elements to the intervention itself’) such as provision of analgesia was also recorded. Reporting of whether an intervention was described as novel was also recorded to understand whether ‘new’ interventions had better reporting details.