Preliminary study of the effects of a placebo chiropractic treatment with sham adjustments

Objective: To identify aspects of the delivery of placebo chiropractic trea tments by using sham adjustments that may cause a treatment effect and that may affect the success of blinding. Design and Setting: Two-period crossover design in a chiropractic college r esearch clinic. Subjects: Eighteen volunteer staff, students, and faculty of the chiropract ic college who reported low-back pain within the last 6 months. Interventions: Flexion-distraction technique was used to perform chiropract ic adjustments, and a hand-held instrument (Activator adjusting instrument) with the pressure gauge set on the 9 was used to perform sham adjustments. The treatment period was 2 weeks, with a total of 4 visits. Main Outcome Measures: The Visual Analog Scale (VAS) for pain and Global We ll-Being Scale (GWBS). Results: Although VAS and GWBS scores improved with both treatments, a some what greater improvement occurred in most cases with the active treatment. Eight of 14 patients interviewed believed that the placebo had a treatment effect. Conclusion: This study provided preliminary information that was useful in planning the protocol for a placebo chiropractic treatment in the randomize d clinical trial for which it was designed.