Inclusion of papers
RCTs, pilot and feasibility studies (with or without a comparator group)
were included. Retrospective studies (e.g. case-control or cohort
studies) were excluded because CONSORT-NPT guidance focuses on reporting
standards in RCTs. Simulation and animal studies were included if they
otherwise met the inclusion criteria. There were no language
restrictions. AVB devices were not limited to a single type or
manufacturer. Any type of comparator was included (i.e. spontaneous
vaginal birth (SVB), Caesarean section or another AVB device).
After removal of duplicate records, titles and abstracts of citations
were screened for eligibility by two researchers (EJH and SR) using
predetermined selection criteria. Reference lists of retrieved articles
were manually searched for additional references, including published
protocols for included studies. Each abstract was independently read by
at least two authors and full-text articles meeting the inclusion
criteria analysed by at least two authors (EJH, SR or NSB).
Discrepancies were resolved by discussion with NSB.