BACKGROUND: Patient-reported outcomes (PROs) on adverse drug reactions (ADRs) are increasingly used in cohort event monitoring (CEM) to obtain a better understanding of patients' real-world experience with drugs. Despite the leading role for patients, little is known about their perspectives on CEM systems. RESEARCH DESIGN AND METHODS: In a cross-sectional open survey following the rationale of the Technology Acceptance Model, we aimed to obtain insight in patients' perspectives on the perceived usefulness, ease of use and attitude toward using a PRO-based drug safety monitoring system for ADRs attributed to biologics. RESULTS: Patients considered structural reporting of ADRs in web-based questionnaires as useful and not burdensome. It was ...