Development of Priority Outcome Domains for Community Mental Health Research via Consensus Among Multiple Stakeholders: Online Delphi Study in Japan

Several core outcome sets (COS) have been developed in the field of mental health; however, the specific outcome domains that should be prioritised in community mental health research remain unclear. This study aimed to identify the key outcome domains for community mental health research in Japan, as determined by multiple stakeholders. First, a comprehensive list of outcome domains was compiled by scoping reviews, focus group interviews, and web-based questionnaire surveys. This was followed by two rounds of preliminary surveys with multiple stakeholders. Finally, three rounds of a web-based Delphi survey were conducted to determine the most important outcome domains of community mental health research in Japan. A total of 96 outcome domains were evaluated by 297 participants, with a response rate of 93.6%. This study identified 24 outcome domains that are essential for community mental health research in Japan. These 24 domains, which reached a consensus, included aspects related to comprehensive symptom assessment and personal recovery. Given that community care serves patients with diverse illnesses, identifying outcome domains that are broadly applicable across different community care settings rather than being limited to specific conditions is critical for future research. The study also highlights differences in perspectives among stakeholders regarding the importance of various outcomes. Despite these differences, several outcome domains have been recognised as being significantly important in the overall consensus. Trial Registration: University Hospital Medical Information Network (UMIN) Clinical Trials Registry: UMIN000044680.