Placebo

Maintaining Similarity

Most traditional Chinese medicine (TCM) remedies are often aromatic, dark-colored, bitter, and pungent. In a randomized crossover clinical trial of a TCM preparation for atopic eczema, all of these characteristics had to be simulated in the preparation of the placebo but without any therapeutic effect remaining. Participants who dropped out because of unpalatability were found to be just as likely in the placebo phase of the crossover trial as when the active treatment was being taken, suggesting that the organoleptic characteristics of the placebo were successfully indistinguishable from that of the active treatment.

Ethics

In a study of the effectiveness of fetal brain cell implants for intractable Parkinson's disease, an ethical debate emerged over the use of nonimplant surgical control groups. Clearly, a theoretically perfect control group would have the presurgical preparation, opening of the skull, insertion of probes, and the closure procedure, but without the implant of fetal brain cells. Ethical objections were raised about the surgical risks for the control group, who would be without any potential benefit. But the need for the sham surgery was reinforced when it was learned that subjects receiving the sham procedure typically exhibited improvements in their Parkinson's symptoms for up to 6 months and were indistinguishable from patients who received the same surgery but with active (implant) treatment. The investigators were unable to attribute the observed improvements to either observer bias or the natural history of the disease.

...