Delphi consensus methodology.

Structure

Each project runs two anonymous online Delphi rounds followed by in-person ratification at Congress. The protocol — scope, panel, evidence method, scoring scale, thresholds, conflict controls and reporting plan — is published before ratings are collected.

Rating scale and thresholds

Statements are rated 1–9: 1–3 disagree, 4–6 uncertain, 7–9 agree. “Unable to rate” responses are excluded from that statement’s denominator.

• Consensus in: at least 80% rate 7–9 and no more than 10% rate 1–3.
• Consensus out: at least 80% rate 1–3 and no more than 10% rate 7–9.
• Borderline (75–79% in the relevant band): revise and re-rate if comments identify a remediable issue.
• No consensus: below 75% in the relevant band, or a conflicting distribution.
• A project may only use a different threshold if it is justified and published before results are seen — thresholds are never lowered after results are known.

Panel composition

Projects target at least 30 participants starting Round 1 and at least 20 completing Round 2. For an international clinical topic, panels target at least five countries, with no single discipline above 50% and no single institution above 20%; industry primary-role participants should not exceed 20%. Patient/public contributors are included where practicable.

Congress ratification and reporting

At Congress the results are discussed and ratified. The meeting may clarify wording without changing meaning, but cannot overturn an anonymous threshold by applause, a show of hands, seniority or office; a material change returns to an anonymous ballot. Remote attendance is not offered.

Consensus is not evidence of efficacy by itself: the strength of a recommendation must reflect the underlying evidence, not merely the percentage agreement. Outputs are reported with the full method (ACCORD/CREDES) and reviewed within three years or earlier on major change.