Sham treatment

A sham treatment is a medical procedure, analogous to a placebo, which is not expected to have any physiological effect, although it may have a placebo effect. There are several differences between placebo given as a medication, and sham treatments.

If the treatment is being done in the control arm of a randomized clinical trial, it is impossible for the clinician performing the procedure to be "blinded" to the treatment. In a double-blind study of a drug, the clinician gives the patient a pill or injection, without knowing if the pill or fluid contains active drug or only inert ingredients. In the double-blind technique, both the clinician and patient cannot be influenced by knowing the actual contents given.

When the treatment involves mechanical action by the clinician, the clinician must be aware if he or she is performing the experimental versus the control act. For example, in a study of acupuncture, needles are inserted in both the control and experimental branches of the trial. In the control arm, the needle is not inserted in a designated acupuncture point, but in an area of skin considered neutral in acupuncture theory. Sham acupuncture, given the extremely thin needles, is rather benign, as it involves no significant risk or pain.

Sham surgery, however, is in a different category of risk and discomfort, and raises ethical questions. General anesthesia, if required, is definitely not a procedure without risk. Further, for the patient to believe that surgery was performed, there must be at least an incision, which further introduces risk and probably postoperative pain. Even a superficial incision has some risk, but if the research trial is of a surgery that requires opening the chest, skull, or abdomen, it is unlikely that a safety board will permit that risk.