OMERACT consensus-based operational definition of contextual factors in rheumatology clinical trials: A mixed methods study.

To develop an operational definition of contextual factors (CF) [1]. Based on previously conducted interviews, we presented three CF types in a Delphi survey; Effect Modifying -, Outcome Influencing - and Measurement Affecting CFs. Subsequently, a virtual Special Interest Group (SIG) session was held for in depth discussion of Effect Modifying CFs. Of 161 Delphi participants, 129 (80%) completed both rounds. After two rounds, we reached consensus (≥70% agreeing) for all but two statements. The 45 SIG participants were broadly supportive. Through consensus we developed an operational definition of CFs, which was well received by OMERACT members. [ABSTRACT FROM AUTHOR]