Table 2 Advantages and challenges of standardizing outcomes across all reviews for a particular condition

Advantage for a systematic review/meta-analysis

39

Development of a COS

23

Improves interpretation/guidance

19

Something about scope

21

Outcome likely to be more appropriate

16

How to persuade authors/trialists/industry to implement

20

Advantage for the design of a new study

13

‘How’ to measure once the ‘what’ has been decided

11

Improves something about the outcome itself

6

Important outcomes not currently being measured

2

Reduces outcome reporting bias

6

Resource to develop

2

Reduces resource requirement

1

Updating process

2

Conflict of interest

1