Clinician expertise (CONSORT-NPT item 15)
Some data were provided about the expertise of clinicians performing AVB in 23 papers (64%). None of the papers explicitly outlined the clinicians’ qualifications although their grade was reported in 22 papers (61%). One paper stated that ‘trained registrars or specialist obstetricians performed all deliveries’ but there was no clarification of the nature of this training. A further paper reported the number of AVBs previously undertaken by each clinician and grouped them according to whether they had performed fewer or greater than 20 procedures however, it was not clear if they used the intervention or comparator to determine the grouping. Only eight papers (22%) reported the number of AVB performed per year in the trial centres. Although 15 (42%) reported the number of clinicians performing AVB in the study, none explicitly stated that the same clinicians performed interventions across all trial arms.
Descriptions of the supervision of clinicians was provided in eight papers (22%); in the majority (n= 7) this referred to trainees being supported by senior clinicians. The one pilot study stated that‘all applications of the device were supervised, and assisted as required, by another obstetrician trained in the use of the device’ but did not specify what this training entailed. Clinician eligibility criteria was mentioned in two papers (6%) ‘obstetric registrars (year 2 to year 4) trained in the use of the vacuum extractor’ and ‘each operator was classified according to prior experience with each instrument [vacuum extractor and forceps]’. None of the papers required clinicians to have completed a certain number of AVBs prior to joining the study. Some information about pre-study training was reported in three papers (8%): ‘opportunity to watch a training video’ , ‘…verbal and written advice’ and ‘…instructed in the use of both methods…’ . An additional paper clarified that ‘clinicians had no specific training in the use of the disposable cup before the trial’ despite the authors acknowledging that this was a new device.
Eight papers (22%) made reference to clinicians’ learning curve, two of which were in relation to devices that were described as new. Of these eight studies, two accounted for the learning curve by comparing event rates across two time periods. The remaining six papers acknowledged that the learning curve may impact on study findings but did not adjust for this.