An Interactive Voice/Web Response System (IVRS/IWRS) is an automated technology system used in clinical trials for two central tasks: patient randomization and clinical trial supply management. Via a telephone or web interface, authorized study site personnel can register a new patient and then receive, in real time, the assignment to a treatment arm and the number of the corresponding medication kit.
These systems are crucial for maintaining the blinding of the study, as the allocation sequence remains concealed. They enable complex randomization schemes (e.g., stratified by site or patient characteristics) and optimize the logistics of the investigational medicinal products. The IWRS can monitor medication inventory at the study sites and automatically trigger resupply shipments to prevent shortages. For CROs, the implementation of a validated and reliable IWRS system is a cornerstone for the efficient and controlled execution of modern, global clinical trials.