What is the primary purpose of the coding in blinded trials?

• A. To ensure randomization only
• B. To reveal identity to investigators
• C. To protect blinding and enable rapid identification in an emergency
• D. To track inventory only

Answer: (C)

The main idea is to preserve blinding while keeping a way to identify the actual treatment quickly if safety issues arise. In blinded trials, each treatment arm is linked to a code, and the mapping is kept secure. This keeps investigators, staff, and participants unaware of who gets which treatment, helping prevent bias in treatment administration and outcome assessment. At the same time, if a dangerous or urgent situation occurs, authorized personnel can unblind using the code to determine the exact treatment, enabling appropriate safety decisions without broadly breaking the blind. So the coding’s purpose is to protect blinding and enable rapid, controlled identification in an emergency.