A patient-reported reference measure is based on a report that comes directly from a patient about the status of their health condition, while an observer-reported reference measure is based on a report from another individual based on observable signs, events, or behaviors related to a patient’s health condition.

For instance, the Borg Rating of Perceived Exertion is an example of a patient-reported reference measure;  the PROMIS Parent-Proxy Physical Activity Item Bank is an example of an observer-reported reference measure.