Table 1 Definitions

On-site monitoring is performed at the investigator sites at which the clinical trial is being conducted, via a physical visit by individuals from the sponsor (and/or its representatives, for example monitors and other CTU staff). It requires access to the medical records of trial participants for the purposes of source data verification/review (SDV/SDR), to confirm the accuracy of data transcription reported on the case report form (CRF), to confirm accurate reporting of all relevant clinical information (e.g. adverse events, concomitant meds), to confirm compliance with the protocol and the principles of GCP and to verify the existence of participants. On-site monitoring also usually includes site file review, verifying investigational medicinal products (receipt, storage, dispensing, accountability and destruction), review of facilities and equipment and training of site staff. On-site monitoring may be pre-planned (routine) or may occur when an issue is found at a site by central or remote monitoring (triggered).

Centralised monitoring is performed in a location away from the investigator site, and often at clinical trial unit/sponsor offices. It involves an evaluation of accumulating data (or lack thereof), performed in a timely manner, supported by appropriately qualified and trained persons (e.g. data managers, statisticians, trial managers, data scientists). The aim is to mitigate specific trial risks defined in the risk assessment document which is completed before recruitment and continually reviewed during the lifetime of the trial. Data are examined by site to identify trends, outliers, anomalies, protocol deviations and inconsistencies. Concerns raised by members of the sponsor/CTU trial team discovered during their contact with the site are also taken into consideration. Centralised monitoring may be the only monitoring (or it may lead to an on-site monitoring visit). It complements and reduces the extent and/or frequency of on-site monitoring and helps distinguish between reliable data and potentially unreliable data ([1] section 5.18.3). Centralised monitoring does not require trial site staff input unless an issue is found.

Remote monitoring is evaluation performed by individuals from the sponsor at a location remote from the trial site. It may include informed consent forms (ICFs) being sent to the central office to enable a number of checks to be performed with appropriate patient consent and data protection issues addressed, accountability log collection, site self-completed monitoring checklists or telephone/video monitoring calls. In some instances, remote SDV/SDR may be considered but this is dependent on sponsor procedures, site procedures and site capacity. Remote SDV/SDR may be performed by the trial site providing pseudonymised source data to the monitor, the monitor having direct access to the trial participant’s electronic medical records or using a video conferencing approach. Remote monitoring requires input from the trial site.

Informed consent is a process by which a subject voluntarily confirms their willingness to participate in a particular trial, after having been informed of all aspects of the trial that are relevant to the subject’s decision to participate. Informed consent is usually documented by means of a written dual signed (patient and person taking informed consent) and dated informed consent form. Monitoring often includes checking that informed consent was correctly taken.