Patient-reported outcome (PRO)

A patient-reported outcome (PRO) is a type of clinical outcome assessment consisting of a measurement based on a report that comes directly from the patient about the status of their health condition, without amendment or interpretation of the response by a clinician or anyone else. PROs capture symptoms (pain, fatigue, nausea), functioning (mobility, daily activities), health-related quality of life and treatment satisfaction, using validated instruments such as the EQ-5D, the EORTC QLQ-C30 or disease-specific scales.

The FDA's 2009 PRO guidance and its Patient-Focused Drug Development guidance series, together with EMA reflection papers, set expectations for instrument development, content validity, translation and linguistic validation, and the interpretation of meaningful change. PROs are increasingly used as primary or key secondary endpoints and to support labelling claims, and are captured electronically as ePRO through eCOA platforms, smartphones or web portals.

PRO data is data concerning health reported in the patient's own words or ratings, often touching on mental health, sexual function, continence or social relationships, which are among the most sensitive categories of information. Free-text PRO items may contain directly identifying details and should be reviewed or avoided. Electronic capture adds device and behavioural metadata that must be minimised, and the ePRO vendor acts as a processor whose hosting location and sub-processors determine transfer requirements. Participants should be told in the informed consent form who sees their responses and that clinicians may not review them in real time, so that PRO diaries are not mistaken for a channel to report emergencies.