Fifteen Years' Use of Patient-Reported Outcome Measures at the Group and Patient Levels: Trend Analysis.

The demand for clinical use of PRO measurements has increased, driven by a wish among patients as well as clinicians to use PRO to promote better symptom assessment, more patient-centered care, and more efficient use of resources. Important technological changes have occurred, creating new opportunities, and making PRO collection and use cheaper and more feasible. Several legal changes may constitute a barrier for further development as well as a barrier for better utilization of patients' questionnaire data. The current legal restrictions on the joint use of health data imposed by the European Union's General Data Protection Regulation makes no distinction between use and misuse, and steps should be taken to alleviate these restrictions on the joint use of PRO data.