Randomised clinical trial

This is a clinical trial where the treatment given to the patients included in the trial is randomised.  This means that the treatment groups are chosen by chance using a formal system. Each group has an equal, chance of being selected. This may be done using a table of random numbers, or by a computer. Randomisation cannot be influenced by the doctor or anyone else, therefore it removes personal preference and other related sources of error (bias). Of course, all patients need to be fully informed about the conditions of taking part in a clinical trial and give their consent to participate.