Strength in Numbers

What types of methodologies are used to develop a consensus statement? I’m in the midst of helping to write a consensus statement manuscript in education and ran into this great review article. It’s from the British Medical Journal in 1995. 

Basically, there are 2 general types of methodologies:

  • Delphi Process
  • Nominal Group Technique 

Delphi Process

An example of a consensus topic might be: How will patient care be affected by the new ACGME Duty Hours rules? The Delphi process takes several rounds of discussions:

  • Round 1: Opinions are expressed on a particular issue and categorized into headings
  • Round 2: Participants rank their agreement with each statement in the summarized opinions.
  • Round 3: Participants view the Round #2 rankings and comments and re-rank their agreement with the opinions.

The final results are analyzed for agreement. If there is no consensus, Round 3 is repeated. The Delphi Process allows a large number of experts to participate in a consensus statement because this entire process can be performed via email.

Nominal Group Technique

In contrast to the Delphi Process, the nominal group technique involves fewer experts (usually 9-12).  Furthermore, this approach requires face-to-face discussion, which adds a more personal element to the methodology.

  • Step 1: Each participant contributes one idea to the facilitator, who records it on a flip chart/projector screen.
  • Step 2: The comments are grouped into different categories.
  • Step 3: Each participant privately ranks each idea.
  • Step 4: The results are tabulated and discussed in a large-group setting.
  • Step 5: Each participant privately re-ranks each idea.
  • Step 6: The results are tabulated to determine consensus.


Jones J, Hunter D. Consensus methods for medical and health services research. BMJ. 1995, 311(7001), 376-80. Download the free PDF.


Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at Bio:
Michelle Lin, MD