How often should monitoring visits occur during a clinical trial?

Monitoring visits during a clinical trial should occur regularly according to a pre-defined schedule. This schedule is established to ensure that the trial adheres to Good Clinical Practice (GCP) guidelines, maintains the integrity of the data being collected, and protects the rights and safety of trial participants. Regular monitoring helps to confirm that the trial protocol is being followed, identify any potential issues early, and ensure that any adverse events or protocol deviations are addressed promptly.

Such a structured approach facilitates continuous oversight throughout the study's lifecycle rather than waiting until the completion of the trial, which would limit the ability to address problems as they arise. The other scenarios presented would not suffice for a comprehensive oversight process required in clinical trials. For instance, conducting visits only if there is a perceived issue would rely too heavily on subjective judgment, which could lead to oversights and serious violations of protocol. Additionally, stating that monitoring visits are not required contradicts the fundamental principles of GCP, which emphasize the importance of monitoring for ensuring data validity and participant safety.