Dear Moacyr,

 

Hope all is well. This is a good question. The best way to answer this question it is to give you an example. Let's say you want to randomize patients to two different treatment options but one is a pill and the other comes as injection. Obviously the patient and investigator will know what treatment the person is taking by determining if they took an injection or a pill. So what you do is give a sham pill (e.g. sugar) to all patients that are randomized to take the active injection and vice versa. Therefore everyone gets an injection and a pill. Of course the sham injection pill should have the same physical characteristics and show the same effects (e.g. taste, smell, etc.) as the active treatment option or else the active medication can still be deciphered. Now the trial is a double-dummy trial.

 

Hope this helps.

 

Thank you for your time and consideration.

 

Please accept my regards.

 

Sincerely,

 

Ahmed

 

_______________________________________
 
Ahmed M. Abou-Setta, MD, PhD

 

Independent researcher/ systematic reviewer
Consulting Senior Systematic Reviewer,
  Chalmers Research Group, CHEO Research Institute (CHEO RI)
  Children's Hospital of Eastern Ontario, University of Ottawa
Member, Editorial Advisory Board, The Open Medical Devices Journal
Member, Geneva Foundation for Medical Education & Research
Member, Menstrual Disorders & Subfertility Subgroup, Cochrane Collaboration

 

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