Cosmin reporting guideline for studies on measurement properties of patient-reported outcome measures and its explanation and elaboration document: translation into Brazilian Portuguese.

PURPOSE: The COSMIN Reporting Guideline 2.0 and its Explanation & Elaboration document have been published to guide researchers in reporting studies on measurement properties of patient-reported outcome measures (PROMs). We aimed to translate the COSMIN Reporting Guideline 2.0 and its Explanation & Elaboration document to report studies on measurement properties of PROMs into Brazilian Portuguese. METHODS: We followed an adapted four-step methodology, including artificial intelligence (AI) forward-translation and back-translation, and appraisal of all written reports by the developers/committee. RESULTS: The AI produced uncommon terms, later standardized to usual Brazilian Portuguese expressions. Back-translation showed minor discrepancies without altering meaning. Expert review corrected grammar and refined terminology. CONCLUSION: The COSMIN Reporting Guideline 2.0 and its Explanation & Elaboration document have been translated into Brazilian Portuguese and can overcome language barriers and guide Brazilian-speaking researchers, clinicians, patients, and policymakers in reporting studies on measurement properties of PROMs. Both documents are available on the COSMIN website.