2.5. Delphi study The Delphi method was used to elicit and evaluate expert opinion on contentious issues where evidence was equivocal or absent. Delphi is a consensus technique used for problem solving and decision-making. It is a feasible and effective method for assessing expert agreement on clinical questions and it is increasingly used in research 22 We used the Delphi method to ascertain and refine expert opinion on the following contentious clinical questions: