Decision analysis in evidence-based decision making.

Many real world decisions have to be made on a limited evidence base, and clinical decisions are at best problematic. We explored some of the reasons why decision making in health care is so complex, and examined how decision analytic techniques might contribute to problem structuring and to implementation of evidence-based practice. We argued that decision analysis could, to some extent, overcome complexity of decision making by a clear structuring of the problem and a formal analysis of the implications of different decisions. Decision-analytic techniques can guide the management of individual patients or can be used to address policy questions about the use of treatment for groups of patients. However, decision analysis is not without its criticisms, e.g. problems are narrowly defined, replacing judgement and dehumanizing care, neglect of process utility and lack of primary data to develop decision analytic models. The development of evidence-based guidelines is a key component of the UK Government's quality strategy led by the National Institute for Clinical Excellence (NICE). However, the guidelines approach may lead to conflict when assessments of the effectiveness of interventions for individuals (whether or not supported by a formal decision analysis) conflict with the recommendations made by NICE for cost and clinical effectiveness for aggregate groups of patients. Decision analysis may or may not help with this but if guidelines are derived from a decision analysis, then the implications of patient preferences should be made clearer. However, decision analysis-derived guidelines will make general recommendations that may not be appropriate for all individuals. Nonetheless, decision analysis does make such implications explicit and propose that the guidelines should be supported by some mechanism for determining individual patient preferences. It will now need to consider whether some of NICE resources should be directed beyond evidence-based guidelines into decision analysis-derived guidelines and into decision analytical techniques to provide support for clinical and cost effective decision making within the patient-clinician encounter.