Using the Delphi expert consensus method in mental health research.

OBJECTIVE The article gives an introductory overview of the use of the Delphi expert consensus method in mental health research. It explains the rationale for using the method, examines the range of uses to which it has been put in mental health research, and describes the stages of carrying out a Delphi study using examples from the literature. METHOD To ascertain the range of uses, a systematic search was carried out in PubMed. The article also examines the implications of 'wisdom of crowds' research for how to conduct Delphi studies. RESULTS The Delphi method is a systematic way of determining expert consensus that is useful for answering questions that are not amenable to experimental and epidemiological methods. The validity of the approach is supported by 'wisdom of crowds' research showing that groups can make good judgements under certain conditions. In mental health research, the Delphi method has been used for making estimations where there is incomplete evidence (e.g. What is the global prevalence of dementia?), making predictions (e.g. What types of interactions with a person who is suicidal will reduce their chance of suicide?), determining collective values (e.g. What areas of research should be given greatest priority?) and defining foundational concepts (e.g. How should we define 'relapse'?). A range of experts have been used in Delphi research, including clinicians, researchers, consumers and caregivers. CONCLUSION The Delphi method has a wide range of potential uses in mental health research.