MATERIALS AND METHODS: Overall methods were guided by the Core Outcome Set Measures in Effectiveness Trials (COMET) initiative. Initial outcome identification was achieved from focus groups with PWLE employing calibrated methods across two low-middle-income countries (China and Malaysia) and two high-income countries (Spain and the United Kingdom). Following consolidation of the results, the outcomes were incorporated into a three-stage Delphi process with PWLE participation. Finally, consensus between PWLE and DPs was achieved using a mixed live and recorded platform. The experiences of PWLE involvement in the process was also evaluated.

RESULTS: Thirty-one PWLE participated in four focus groups. Thirty-four outcomes were suggested across the focus groups. Evaluation of the focus groups revealed a high level of satisfaction with the engagement process and some new learning. Seventeen PWLE contributed to the first 2 Delphi rounds and 7 to the third round. The final consensus included 17 PWLE (47%) and 19 DPs (53%). Out of the total of 11 final consensus outcomes considered essential by both PWLE and health professionals, 7 (64%) outcomes mapped across to ones that PWLE initially identified, broadening their definition. One outcome (PWLE effort required for treatment and maintenance) was entirely novel.