Controversy and Debate Series on Core Outcome Sets. Paper 5: large-scale, mixed-methods knowledge exchange to establish core outcomes — The SONG approach

We read with interest the article by Chevance et al. in this issue in which the authors propose three adaptations to the Core Outcome Measures in Effectiveness Trials (COMET) guidance for developing core outcome sets (COS):

•Replace interviews/focus groups with an online international survey to elicit outcome domains from patients and stakeholders.
•Replace the multiround Delphi survey with a single-round, international ranking survey to determine priorities for outcomes.
•Conduct an online survey that includes patients when selecting outcome measures.

The author's primary rationale for these amendments is that insufficient numbers and diversity of patients participate in interviews and focus groups, and they highlight concerns around using the Delphi method in a COS context. They suggest that overall patient involvement is limited in COS development, there is poor engagement of stakeholders internationally (particularly in non-English speaking regions), and that these issues may constrain the credibility and implementation of COS.