Interventions standardisation (CONSORT-NPT item 5b)
Conditions for device use were reported in 35 papers (97%) although in 21 (66%) it was not clear whether these were the same across all study arms.
Information about any mandatory, flexible and optional operative components or steps was provided in 23 papers (64%). All except three related to ventouse, even when forceps were the intervention rather than the comparator (Table 3). ,
Seventeen papers (42%) reported flexibility in the devices clinicians were permitted to use, relating to the comparator group (n=12), intervention (n=1) and both intervention and comparator (n=4). Five of the papers described flexibility in the specific brand of device that could be used, (ventouse = 4, forceps = 1), stating that the choice was left to the clinician. In a further study, women were randomised by clinician preference, ‘Decision for forceps delivery or ventouse extraction was of consultant and the choice of method was dependent entirely on his/her judgement’.
Standardisation was also reported for co-interventions in 11 papers (31%) and related to the provision of analgesia (n =4) and use of episiotomy (n =9) (Table 2).