Using experts to inform health care decision making: what is role for subjective priors and can better guidance maximise their potential?

The evidence used to establish cost-effectiveness and inform health care decision making is typically uncertain. In these situations, the experience of experts is essential. Experts are used in many formal decision making processes, to interpret available evidence and also to provide their own subjective priors, which can be used in the absence of evidence or where evidence is unsuitable. The presentation reports on a recently completed project to develop guidance for the formal elicitation of expert opinion in health care, focussing on the elicitation of prior distributions from multiple experts. Experimental evidence was gathered to determine the most suitable approach for elicitation to inform health care decision making. The complexities and challenges in using structured and best practice approaches across a range of decision making contexts is also explored, for example in evaluations carried out earlier in the R&D pathway and for complex interventions.