The Delphi Technique: Methodological Considerations and the Need for Reporting Guidelines in Medical Journals

Abstract

Background. The Delphi technique has been increasingly used in healthcare research over the past decade. Study aim. To present the development workflow and methodological issues encountered while designing a Delphi study targeting family care practitioners in northeast Romania. Method. Extraction from existing literature and analysis of several reported factors which may decrease the internal validity of a Delphi study and therefore, the overall study reliability: expert selection criteria and process, expert retention, dropout management, types of questionnaires, questionnaire delivery, data analysis in qualitative and qualitative rounds and construct of Likert questionnaires. Result. Based on the existing literature data and taking into account the study objectives we propose a design allowing a decrease of the systematic bias and an improvement of the study findings: purposive stratified sampling, financial incentives, dropouts’ inclusion in the analysis, dual administration of questionnaires, open-ended questionnaire for round 1, Likert forms with 7 ascending, fully labeled, horizontal response options including a midpoint. Conclusion. Careful consideration should be given to all variables that may influence the internal validity or induce a consensus bias in healthcare studies using the Delphi technique. A more detailed and standardized reporting is needed for Delphi studies published in biomedical journals and we propose a checklist to be used by readers and editors.