Use of Delphi in health sciences research: A narrative review

The use of the Delphi technique is prevalent across health sciences research, and it is used to identify priorities, reach consensus on issues of importance and establish clinical guidelines. Thus, as a form of expert opinion research, it can address fundamental questions present in healthcare. However, there is little guidance on how to conduct them, resulting in heterogenous Delphi studies and methodological confusion. Therefore, the purpose of this review is to introduce the use of the Delphi method, assess the application of the Delphi technique within health sciences research, discuss areas of methodological uncertainty and propose recommendations. Advantages of the use of Delphi include anonymity, controlled feedback, flexibility for the choice of statistical analysis, and the ability to gather participants from geographically diverse areas. Areas of methodological uncertainty worthy of further discussion broadly include experts and data management. For experts, the definition and number of participants remain issues of contention, while there are ongoing difficulties with expert selection and retention. For data management, there are issues with data collection, defining consensus and methods of data analysis, such as percent agreement, central tendency, measures of dispersion, and inferential statistics. Overall, the use of Delphi addresses important issues present in health sciences research, but methodological issues remain. It is likely that the aggregation of future Delphi studies will eventually pave the way for more comprehensive reporting guidelines and subsequent methodological clarity.