Participating in core outcome set development via Delphi surveys: qualitative interviews provide pointers to inform guidance

Objectives To explore participants’ views of Delphi
surveys in core outcome set (COS) development.
Study design and setting Patients and health
professionals (n=24) from seven recently concluded COS
studies that had involved a Delphi survey took part in
semistructured qualitative interviews (telephone and email
exchange). Interviews explored participants’ understanding
of COS and their experiences of the Delphi survey. Analysis
was thematic.
Results Several interviewees had previously participated
in two or more COS or Delphi surveys. Those with multiple
experiences of participation generally understood the
purpose of COS and were satisfied with the Delphi
survey. However, some interviewees who were first-time
participants struggled to understand the purpose
of COS and aspects of the Delphi survey, which limited
their contribution and satisfaction with the study.
Interviewees also differed in how they interpreted and
subsequently used the written documentation provided
to COS participants. Some interviewees wanted guidance
regarding whose perspective to take into account when
scoring outcomes and on how to use the scoring system.
Interviewees reported being motivated to take part by the
international and expert consensus aspects of the Delphi
survey. A few interviewees reported experiencing either
positive or negative emotional impacts arising from when
they reviewed outcomes and stakeholder feedback.
Conclusion This study identifies important information
that should be communicated to COS Delphi study
participants. It also indicates the importance of
communicating about COS Delphi studies in ways that are
accessible and salient to participants, to enhance their
experience of participation and make the process more
meaningful for all.