During a clinical trial, the investigator must ensure which of the following?

Ensuring that essential documents are managed and accessible is a fundamental responsibility of the investigator during a clinical trial. Essential documents, as defined by ICH E6 guidelines, include those that demonstrate the compliance of the trial with Good Clinical Practice (GCP) and regulatory requirements. These documents serve as a critical source of evidence that the study is conducted properly and ethically.

By keeping these documents organized and readily accessible, the investigator facilitates the monitoring and auditing processes, which are essential for ensuring data integrity and participant safety. Furthermore, this practice contributes to the overall transparency of the trial, allowing for proper oversight by regulatory authorities and stakeholders involved in the research process.

In contrast, while data security and participant confidentiality are important, the statement regarding exclusive control of participant data or nondisclosure of subject records might imply restrictions that are not compatible with the principles of ethical research conduct, which emphasizes the rights and welfare of participants. Similarly, it is essential to inform participants of their rights in a clinical trial, making options that suggest otherwise not aligned with ethical standards.