Allocation concealment in clinical trials
According to Question 19 from the first paper of 2016, the official Delaney definition of allocation concealment is:
"Procedure for protecting the randomization process and ensuring that the clinical investigators and those involved in the conduct of the trial are not aware of the group to which the subject has been allocated"
In human language:
- This is technique of preventing selection bias.
- The selection of patients is randomised, and nobody knows what treatment the next enrolled patient will receive.
- A truly random sequence of allocations prevents the investigators from being able to predict the allocated treatment on the basis of previous allocated treatments.
Difference between blinding and allocation concealment
- Allocation concealment prevents the investigators from predicting who is getting what treatment before the patient is enrolled.
- Blinding prevents the investigators from knowing who is getting what treatment after the patient is enrolled.