Consensus methodology refers to structured approaches used to achieve agreement among a group of experts or stakeholders, particularly when empirical data is incomplete or expert opinions diverge.

• Process: Iterative rounds of anonymous questionnaires among experts. Feedback is shared between rounds.
• Goal: Converge toward consensus.
• Applications: Health guidelines, forecasting, policy development.
• Advantages: Anonymity reduces bias; allows remote participation.
• Limitations: Time-consuming; risk of participant drop-off.

• Process: Structured in-person session. Ideas are generated silently, then shared and ranked.
• Goal: Rapid prioritization through voting.
• Applications: Needs assessment, guideline creation.
• Advantages: Promotes equal participation; fast.
• Limitations: Requires physical presence; no anonymity.

• Process: Combines Delphi with systematic literature review. Experts rate clinical scenarios in two rounds.
• Goal: Assess appropriateness of interventions.
• Applications: Clinical decision-making tools.
• Advantages: Evidence-informed; highly structured.
• Limitations: Resource and time-intensive.

• Process: Public or expert panel discusses and issues a joint consensus statement.
• Goal: Incorporate diverse perspectives.
• Applications: Ethical issues, public health, biotechnology.
• Advantages: Democratic, transparent.
• Limitations: Complex logistics; unpredictable outcomes.

• Process: Online version of Delphi; often with fewer rounds.
• Goal: Speed up consensus while maintaining rigor.
• Applications: Virtual expert panels, core outcome sets.
• Advantages: Efficient and accessible.
• Limitations: May lack depth or iterative refinement.

• Evidence is limited or conflicting
• Expert opinion is needed to guide practice
• Developing:
  1. Clinical practice guidelines
  2. Core outcome sets
  3. Ethical or policy frameworks

• CREDES – for Delphi methodology
• COS-STAD – for developing Core Outcome Sets
• AGREE II – for guideline reporting quality

Feel free to adapt for specific projects (e.g. cranioplasty outcome sets or neurosurgical guidelines).