Testing the applicability and additional value of a consultation round after the consensus meeting in the development of two core outcome sets

Objectives Test applicability and additional value of a consultation round after the consensus meeting in the development of core outcome sets (COSs). Study design and setting In two COS procedures (Core Outcome Set for the prevention and treatment of fetal GROwth restriction: deVeloping Endpoints (COSGROVE) and Definition and Core Outcomes on Hyperemesis Gravida (DCOHG)) that followed the Core Outcome Measures in Effectiveness Trials methodology, the first round of convergence to consensus among stakeholder groups in an online Delphi procedure was followed by a face-to-face consensus meeting during which a COS was formulated. We subsequently presented the COS to the online panel in a consultation round to confirm that the online panel agreed with the choices made at the consensus meeting, defined as 80% agreement. Participants In the COSGROVE Study, there were eight stakeholder groups, and 83 out of 107 participants completed the consultation round. In the DCOHG Study, there were four stakeholder groups, and 96 out of 125 completed the consultation round. Interventions Adding a consultation round after completing a modified Delphi method with a consensus meeting. Results There was a level of agreement of 81% and 84%, respectively, in the consultation round of both procedures. This was above the preset level of agreement. The consultation round yielded additional suggestions to refine COS formulation in one of the studies. Conclusion Our study shows that in two procedures, the online expert panel agreed with the participants of the consensus meeting in these procedures, lending validity to existing COS methodology. Future studies could evaluate whether bringing back the COS for confirmation after the consensus meeting could potentially increase the uptake of the final COS.