Accrual rate refers to which aspect of a trial?

• A. The rate of data entry
• B. The rate of site activation
• C. The rate of adverse event reporting
• D. The rate at which subjects are enrolled

Answer: (D)

Accrual rate is about how quickly participants are enrolled into the trial. It measures enrollment pace, not data entry, site activation, or safety reporting. In study planning, you estimate how many subjects you can enroll per unit time (for example, per month) to set realistic timelines, power, and budget. If enrollment falls short of the projection, you might add sites, adjust outreach, or extend the enrollment window. The other options describe different processes: data entry speed, how fast sites come online, and how quickly adverse events are reported. So the pace of enrolling subjects best defines accrual rate.