Which of the following can be a reason to discontinue a subject in a clinical trial?

Discontinuing a subject from a clinical trial is often necessary to maintain the integrity of the study and ensure the safety of participants. Non-compliance, pregnancy, or intolerable medical events are all valid reasons for discontinuation.

Non-compliance refers to a participant's failure to follow the study protocol, which can include not adhering to the medication regimen or missing scheduled visits. This can impact the data collected, compromising the trial's validity.

Pregnancy may present a safety concern depending on the nature of the study and the investigational product being tested. It may also affect the participant's ability to continue in the trial as the treatment may not be safe or ethically appropriate during pregnancy.

Intolerable medical events, such as adverse reactions or severe side effects related to the investigational treatment, necessitate discontinuation for the participant's safety. These events would be closely monitored, and if deemed serious enough, continuing in the trial could pose risks to the subject’s health.

Each of these reasons directly relates to the participant's safety and the integrity of the trial data, making them appropriate justifications for discontinuation.