The German version of the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM): Factorial validity, internal consistency, and gender differences in a large outpatient sample.

Objective: The Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) is a pantheoretical mental health assessment instrument that has been translated into over 50 languages. Despite its widespread international use in clinical practice and research, the psychometric properties of CORE-OM require further investigation.

Method: We explored and tested the factorial validity of the German version of CORE-OM in a large adult clinical outpatient sample (N = 4355) using exploratory and confirmatory factor analysis. Internal consistency and correlations of the four CORE-OM domains (Well-being, Problems, Functioning, and Risk) across gender identities are presented.

Results: While no model satisfied all fit criteria in confirmatory analyses, the three-factor structure derived from exploratory factor analysis outperformed the theoretically favored four-domain solution. Internal consistency was overall acceptable with Well-being scoring slightly lower than the other scales. Non-binary respondents had statistically significantly higher average Risk scores then men and women.

Conclusion: Our findings support the reliability of CORE-OM and lend limited support to its factorial structure in a large German-speaking sample, and emphasize the importance of considering diverse gender identities in mental health assessment. The analyses further indicate a need for refinement in the scoring of CORE-OM in various cultural contexts.