Panellist consistency in the assessment of medical appropriateness.

Where information about the appropriateness of a surgical procedure is lacking, expert panels have been used to establish guidelines for medical practitioners. Such a panel was convened to assess the appropriateness of percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery in the Netherlands. The panel, consisting of interventional cardiologists and cardiothoracic surgeons, used a modified Delphi process to rate 1126 clinical indications over two rounds. This article describes the degree of change in both agreement amongst members and in the appropriateness ratings over the two rounds, and examines the internal consistency of the ratings of individual panellists. Over the two rounds, agreement increased. Although most appropriateness ratings remained unchanged, there was significant movement from equivocal ratings to determinate ratings. While individual members showed some degree of inconsistency in their scoring, the panel as a whole scored very consistently. The observed changes in appropriateness were consistent with expectations, showing that the appropriateness method is used logically and consistently by panellists.