Results
Our search identified 5,227
individual citations. We excluded 5,096 records at the title and
abstract screen, and a further 99 after screening the full paper (see
Figure S2). A summary of reasons for exclusion of the full papers is
presented in Table S1. Thirty-two papers relating to 26 individual core
outcome sets met the inclusion criteria representing published COS
related to maternal (n = 18 papers; 17 COS) and neonatal (n = 14 papers;
9 COS) health.
Study and registry characteristics
Of the 18 papers related to maternal COS, 17 were primary journal
articles and one was a published conference paper (secondary paper)
(outlined in Table S2). Of the 14 papers related to neonatal COS, 10
were primary journal articles three were published conference papers and
one was a meeting abstract (secondary papers). Fifteen COS (58%) were
published from 2017 onwards (range 2006 – 2020). All 26 COS projects
were registered with COMET and 11 with CROWN: four as published and
seven as ongoing projects.
Eighteen studies (69%) were published in free to view journals and
three quarters were funded projects (n = 20). Of the eight COS with
separately published protocols, all related COS were published from 2017
onwards. Fifteen individual systematic reviews were identified relating
to 11 separate COS, with all but one COS published from 2016 onwards.
Fourteen of the 26 COS (54%) were included in previous reviews. The
current review includes twelve new COS (46%).
Methods used in COS
development
The scope and methods for development are outlined in Table S3 and
summarised in the following sections.
Scope
The scope of included studies is summarised in Table 1. While most COS
were intended for research (81%), almost one in five were also
recommended for clinical practice. One COS developed by ICHOM was
designed specifically for clinical application.19 Of
the 25 COS developed for research, most cover any intervention (81%).
[Insert Table 1 about here]
Stakeholders involvement
Stakeholder groups involvement is summarised in Table 2. Clinical
experts from 18 disciplines were involved in COS development.
Neonatologists (54%), obstetricians (46%) and midwives (42%)
represented the largest clinical expert groups involved. Public
representation was sought in 18 COS (69%). Countries represented by
stakeholder groups are outlined in Table S4. Of the 18 COS for which
country representation data was available, each COS stakeholder group
represented a median 26 countries (range 1- 36). High income countries,
as defined by the World Bank
(https://www.worldbank.org/), dominated
representation. Developing countries were poorly represented in almost
all COS.
Patient participation and retainment was reported in 18 COS projects
(Table S5). Among 18 Delphi studies, half of all stakeholders were
retained at final round (Mdn = 48%, range 20 - 86%). Reported median
patient participation in 13 Delphi studies was 16% (range 11 - 53%) at
round one and 16% (range 2 - 61%) at the final round. It was not
possible to evaluate healthcare professional participation and attrition
by discipline due to limitations of joint category reporting in several
studies.
[Insert Table 2 about here]
Methods used in consensus
process
Methods used during the consensus process are summarised in Table 3.
Commonly, the initial list of outcomes was generated by
literature/systematic review (n = 19; 73%). Consensus was most often
reached through electronic Delphi procedure (n = 19, 73%) using either
a two- (n = 8) or three-round (n = 10) process. Around half of all COS
projects used a combination of Delphi with some form of final consensus
meeting (n = 15). Scoring and consensus processes were employed in 18
(69%) COS. Of these, a 9-point Likert scale was the most common
procedure to score outcomes (72.2%) and the 70%/15% process (see
example description in Table 3) was the most common consensus definition
(67%).
[Insert Table 3 about here]
Standard of COS
development
Each COS was evaluated against COS-STAD minimum standards as outlined in
Table S6 and summarised in Table 4. None of the included studies met all
minimum standards for COS development. Median number of standards met
was 8 (range 5 – 11). For 14 COS published up to and including 2017,
the medium number of standards met was 6.5 (range 5-11), while the
median number of standards met for COS published from 2018 onwards was
10 (range 6 – 11).
[Insert Table 4 about here]
Scope specification (Standards
1–4)
All 26 COS (100%) described in some way the research or practice
setting (Standard 1 ), health condition (Standard 2 ),
population (Standard 3 ), and intervention (Standard 4 )
covered by the COS, meeting the criteria representing the scope covered
by the COS. Where no specific intervention was specified, any
intervention was assumed.
Stakeholders involved (Standards
5–7)
Eighteen (69%) studies met all three standards for stakeholder
involvement including health professionals, researchers and patients or
their representatives. Some assumptions were made regarding research and
health professional stakeholder involvement. Author contribution and
affiliation indicated standards were most probably met in these studies.
Health care professionals and researchers were well presented in all
stakeholder groups. Eighteen studies (69%) met the criteria for patient
or representative involvement. While eight (31%%) did not meet this
criterion, these were assumed as stakeholder involvement occurred during
professional conference meetings or expert working groups.
Consensus process (Standards
8-11)
No studies met all standards for the consensus process. As such
standards within this domain are addressed individually.
Standard 8: Initial list of outcomes considered both
health care professionals’ and patients’
views’
Six studies (23%) met this standard, seven were unclear (27%) and 13
(50%) did not meet the standard. Those that met the standard
demonstrated clear consideration of patient views by conducting either
qualitative research studies of patients’ views or conducted patient
interviews to generate the initial list of outcomes. Jones et al., for
example, stated, ‘The list of core outcomes was developed incollaboration with the PCG consumers group….outcomes that
were of importance to them’ 20 whereas Van’t Hooft et
al.,21 stated ‘Patient representatives and
parents were invited through social media…to share their opinions
regarding outcomes relevant to preterm birth ’.