Sources
We reviewed all studies registered with the COMET and CROWN initiatives
from inception (2010) through to March 2020 (figure 1). COMET is a
registry of COS studies, including citations to relevant protocols,
systematic reviews, and completed core outcome sets. Studies are
categorised by pre-defined ‘disease categories’ or ‘disease names.’ We
included all disease categories to identify all studies related to
women’s and neonatal health. The register is maintained by searches of
the Cochrane Methodology Register, MEDLINE, and Scopus, with core
outcome developers also encouraged to register prospectively.(7, 12) The
CROWN initiative maintains an informal database which encourages core
outcome developers to register their study.(12)