The Delphi Method. Figure 1 outlines how the Delphi method proceeded through three rounds of consultation with expert panel members in order to achieve consensus. If between 90-100% of panel members rated a statement as either Essential or Important, the statement was endorsed as a guideline. If between 80-89% of panel members rated a statement as either Essential or Important, the statement was then entered into a second round questionnaire to be rated again. To perform this next round of re-rating, participants were given a report outlining the results of the previous round, which showed their own individual ratings as well as the pooled ratings of the group. If the statement failed to meet the 90% endorsement level in the second re-rating round, it was then rejected. If a statement received a rating of 79% or less, it was rejected outright. Participants provided feedback in Round 1 which contributed to the edition of new items in Round 2. Only those items that fell into the re-rate category at the end of Round 2 were entered into a third a final round.
Hart et al. BMC Psychiatry 2009 9:47 doi:10.1186/1471-244X-9-47