We were conducting a trial for a painful diabetic neuropathy (PDN) drug and were investigating why one site had an especially high placebo response rate. Then one of our representatives, waiting in the site’s lobby to meet with the principal investigator, pinpointed the likely reason when a patient walked in the door.
“Mrs. Jones,” the receptionist beamed, “you look fantastic today.” The compliment, however benign and well-intentioned, was exactly the kind of interaction sites need to avoid. Positive reinforcement from the staff can easily color a patient’s perception of how well the treatment is working and must be avoided. That’s especially true in pain trials, which are often undermined by high placebo response.
Pain trials are uniquely challenging because they rely so heavily on patients’ own assessments. While researchers will always need to account for the placebo effect when studying indications as subjective as neuropathic pain, there are ways to increase the likelihood of achieving objective trial outcomes.