 Clinical trials now often report so-called patient-reported outcome measures or PROMs. A PROM is a questionnaire given to patients to evaluate certain aspects of their quality of life, functioning or health status after a medical intervention without interpretation of the patient’s response by a clinician or other people. It might ask, for example, how difficult patients find it to climb up a flight of stairs after hip surgery or whether or not a cancer treatment helps them to pursue their hobbies. The main goal of a PROM is the assessment of treatment benefit or risk in cases where the medical outcome is best known by the patient or best measured from the patient perspective.