How can we do the randomization for a clinical study in a population - (Jun/28/2012 )
It depends on the type of study. If you were doing a drug trial for instance, you should do a double blind of the treatments (both doctor/person handing over the drugs and patient know who is getting drug and who control). For other types you might have a number of patients with the same diagnosed condition and you randomly sample from that population - talk to a statistician, they will be able to help design this well.
You should also discuss with your supervisor - they will know how to go about this and any regulations you need to follow.
Also in the end remember that these are people, and patient samples are precious, don't annoy your patients and don't waste samples!