Use of the Delphi technique to develop standards for quality assessment in diagnostic radiology.

The Delphi technique is a method for obtaining answers to questions that are issues of uncertainty even to experts. The aim of this study was to use the Delphi technique to develop two standards for the assessment of the diagnostic performance of dentists using radiographs. Two Delphi consensus procedures were initiated to determine the presence of visible abnormalities on radiographs and their pathological nature. A panel of expert radiologists was independently selected. This panel reached consensus on the items of both Delphi procedures through a number of rounds of written correspondence. The outcomes of the procedures were compared to a histopathologic norm for the presence of pathology. The group procedure was described as well as tested for dominance on part of any of the individual panellists. It was found that up to 98 per cent agreement occurred among the majority of panellists on items of the procedures. The panellists were significantly better than dentists in the diagnosis of pathology (P < 0.05) and kept improving during the process of consensus formation. In neither of the Delphi procedures was the judgement of any panellist dominant (P > 0.4). It is concluded that, if carefully controlled, the Delphi technique may be used in the development of diagnostic standards in oral radiology.