Fig 1.
PRISMA flowchart.
Table 1.
Reasons for exclusion of records at full text stage.
Table 2.
COS minimum standards assessments summary (N = 30).
Fig 2.
Year of first publication of each COS study (n = 337).
Table 3.
The scope of included studies (n = 337).
Fig 3.
Number of COS developed in each disease category (n = 337).
Table 4.
Participant groups involved in selecting outcomes for inclusion in COS (n = 337).
Table 5.
Nature of patient participation where detail is reported (n = 23).
Table 6.
Geographical locations of participants included in the development of each COS (n = 281).
Table 7.
The methods used to develop COS (n = 337).