Posted on February 24, 2015 by
Placebo effect of medication cost in Parkinson disease
A randomized double-blind study
- Alberto J. Espay, MD, MSc,
- Matthew M. Norris, MEng,
- James C. Eliassen, PhD,
- Alok Dwivedi, PhD,
- Matthew S. Smith, BS,
- Christi Banks, CCRC,
- Jane B. Allendorfer, PhD,
- Anthony E. Lang, MD, FRCPC,
- David E. Fleck, PhD,
- Michael J. Linke, PhD and
- Jerzy P. Szaflarski, MD, PhD
- Correspondence to Dr. Espay: email@example.com
Objective: To examine the effect of cost, a traditionally ?inactive? trait of intervention, as contributor to the response to therapeutic interventions.
Methods: We conducted a prospective double-blind study in 12 patients with moderate to severe Parkinson disease and motor fluctuations (mean age 62.4 ? 7.9 years; mean disease duration 11 ? 6 years) who were randomized to a ?cheap? or ?expensive? subcutaneous ?novel injectable dopamine agonist? placebo (normal saline). Patients were crossed over to the alternate arm approximately 4 hours later. Blinded motor assessments in the ?practically defined off? state, before and after each intervention, included the Unified Parkinson’s Disease Rating Scale motor subscale, the Purdue Pegboard Test, and a tapping task. Measurements of brain activity were performed using a feedback-based visual-motor associative learning functional MRI task. Order effect was examined using stratified analysis.
Results: Although both placebos improved motor function, benefit was greater when patients were randomized first to expensive placebo, with a magnitude halfway between that of cheap placebo and levodopa. Brain activation was greater upon first-given cheap but not upon first-given expensive placebo or by levodopa. Regardless of order of administration, only cheap placebo increased activation in the left lateral sensorimotor cortex and other regions.
Conclusion: Expensive placebo significantly improved motor function and decreased brain activation in a direction and magnitude comparable to, albeit less than, levodopa. Perceptions of cost are capable of altering the placebo response in clinical studies.
Classification of evidence: This study provides Class III evidence that perception of cost is capable of influencing motor function and brain activation in Parkinson disease.
- ? 2015 American Academy of Neurology