Patient-reported outcome (PRO) is a measurement based on a report that comes directly from the patient (i.e., participant) about the status of a patient’s health condition without interpretation of the patient’s response by a clinician or anyone else. A PRO can be measured by self-report or by interview, provided that the interviewer records only the patient’s response. Symptoms or other unobservable concepts known only to the patient (e.g., pain severity or nausea) can only be measured by PRO measures. PROs can also assess the patient perspective on functioning or activities that may also be observable by others.
U.S. Food and Drug Administration (FDA) Patient-Focused Drug Development Glossary
NCATS Toolkit for Patient-Focused Therapy Development: Clinical Outcome Assessments
U.S. Food and Drug Administration (FDA): Clinical Outcome Assessment (COA) – Frequently Asked Questions