Published protocols
Twenty-four protocols outlining COS development studies were identified
(table S2)(21-44) including: 14 (58%) in pregnancy and childbirth, 3
(13%) benign gynaecology and subfertility, 6 (25%) newborn and
neonatal health and 1 (4%) in oncology (table S2). The scope of the
proposed COS including the health condition, population, intervention
and setting was clearly specified in 20 (83%). Ten (42%) identified
the steering group for the protocol. Twenty-one (87%) described their
intention to carry out a systematic review of published research to
identify potential core outcomes; three (13%) referred to already
completed systematic reviews. Eight (33%) described the use of
qualitative methods to identify potential core outcomes: 6 described
interviews or focus groups alongside qualitative reviews and 2 proposed
only qualitative reviews. Eleven (46%) protocols discussed the impact
of missing data and/or attrition bias. All intended to identify core
outcomes using a modified Delphi method and 23 proposed a consensus
development meeting (96%). Overall, only four protocols (17%)
completely fulfilled COSāSTAP criteria (table S3).