Headache is a leading cause of disability and suffering. One major challenge in developing device treatments is demonstrating their efficacy given devices' often-high placebo rate. This paper reviews the importance of validating
sham devices as part of finalizing the design for larger-scale prospective randomized controlled trials in patients with
chronic headache as well as the results of a prospective, single-blind trial to validate two potential
sham noninvasive thermal
nerve block devices. Study participants were trained to self-administer thermal
nerve block treatment using
sham devices in an office visit. Two different
sham systems with different temperature profiles were assessed. Devices were offered for patients to use daily at-home for one week to assess the durability of
sham placebo effects before participants were given active treatment in a second office visit followed by another optional week of self-administered active treatment at-home use.
Sham treatments reduced
pain scores by an average of 31% from 6.0 ± 2.3 to 4.3 ± 3.3, including two participants who fell asleep during the in-office treatment and woke up with no
pain, but whose
pain recurred after returning home during at-home use of the
sham system. In-office active treatments reduced
pain scores by 52% from 6.7 ± 2.1 to 3.3 ± 2.9 with sustained
pain relief during optional at-home use. Successful blinding for the study was confirmed with an ideal Bang's Blinding Index of 0 and an ideal James' Blinding Index of 1. Both the
sham and active treatments were viewed by participants as highly credible, and credibility increased from the beginning to end of
sham treatments on average.