Updating the OMERACT filter: implications for patient-reported outcomes.

Objective: At a previous Outcome Measures in Rheumatology (OMERACT) meeting, participants reflected on the underlying methods of patient-reported outcome (PRO) instrument development. The participants requested proposals for more explicit instrument development protocols that would contribute to an enhanced version of the "Truth" statement in the OMERACT Filter, a widely used guide for outcome validation. In the present OMERACT session, we explored to what extent these new Filter 2.0 proposals were practicable, feasible, and already being applied.

Methods: Following overview presentations, discussion groups critically reviewed the extent to which case studies of current OMERACT Working Groups complied with or negated the proposed PRO development framework, whether these observations had a more general application, and what issues remained to be resolved.

Results: Several aspects of PRO development were recognized as particularly important, and the need to directly involve patients at every stage of an iterative PRO development program was endorsed. This included recognition that patients contribute as partners in the research and not merely as subjects. Correct communication of concepts with the words used in questionnaires was central to their performance as measuring instruments, and ensuring this understanding crossed cultural and linguistic boundaries was important in international studies or comparisons.

Conclusion: Participants recognized, endorsed, and were generally already putting into practice the principles of PRO development presented in the plenary session. Further work is needed on some existing instruments and on establishing widespread good practice for working in close collaboration with patients.