Patient involvement:
A patient representative (FT) was included in the project management
group in order to ensure patient input into all aspects of the work.
Results
Eligible studies
The literature search yielded a total of 2699 citations: after review of
the abstracts, 138 were assessed in full. Eighty studies which did not
meet the inclusion criteria were excluded, leaving 58 relevant studies.
Of these, 19 were completed studies with prioritized outcomes and 39
were COS protocols, where the final COS was not yet published (Figure
2). For detailed information about
the included studies, see table S1. Excluded studies and the reason for
exclusion can be found in table S2. Of the 39 identified ongoing COS
studies, the full protocol was identified for 10. The ongoing studies
are described in table S3
Published core outcome
sets
Of the completed studies, 12 had an expressed intention to develop a COS
(8-19). In the remaining seven studies, outcomes were also prioritized,
but the main aim of the studies varied somewhat (20-26). The primary aim
of two articles was to prioritize future research questions, and this
included prioritizing the outcomes to be assessed (20, 26). Two other
articles investigated which outcomes should be prioritized in a
composite outcome, while other studies considered which outcomes should
be assessed in clinical follow-up of patients (21-25).
A brief overview of the included
completed studies is presented in Table 1.
Of the completed studies, all were
published after 2007 and 52% were published during 2018 and 2019
(Figure 3A). The large number of ongoing COS projects identified also
indicates a high degree of activity in the field.
Sorting the studies into
categories (figure 3B), discloses that most COS, both completed and
ongoing, focus on pregnancy and pregnancy-related complications and
conditions. There are surprisingly few COS for labour and delivery and
physical conditions associated with giving birth. We could, for example,
not find any COS with a focus on vaginal delivery or caesarean section
delivery as a whole or COS with a focus on interventions related to the
actual delivery process. All the identified COS concerned physical
health conditions, no COS where identified with respect to mental health
during pregnancy or after childbirth.