Abstract Details

Title Nocebo In Myasthenia Gravis: A Systematic Review And Meta-Analysis Of Randomized Placebo-Controlled Trials

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P5 - Poster Session 5 (5:30 PM-6:30 PM)

Poster/Presentation
Number 12-038

Objective To examine the prevalence of adverse events in patients receiving placebo in randomized controlled trials (RCTs) for myasthenia gravis.

Background The term nocebo refers to the adverse events occurring when taking a placebo. Nocebo phenomena results from negative expectations and reflex conditioning from past experiences and can lead to medication non-adherence. Nocebo has been closely studied amongst neurological conditions affecting the brain and spinal cord but is yet to be explored with respect to peripheral nervous system conditions such as myasthenia gravis.

Design/Methods A systematic PubMed and Web of Science search of myasthenia gravis RCTs with a pure placebo group was conducted. The number of adverse events (nocebo adverse event rate) and the number of treatment withdrawals because of adverse events (nocebo dropout rate) was then assessed.

Results Data was extracted from six RCTs fulfilling the search criteria. Four out of five placebo-treated participants, 80.1% (95% CI: 75.0% - 84.5%), reported at least one adverse event and approximately one in forty-two placebo treated patients, 2.4% (95% CI: 1.0% - 5.0%), discontinued due to adverse event severity. The most common adverse events were nausea, diarrhea, vomiting and nasopharyngitis. The nature of adverse events was similar amongst all patients independent of the study arm to which they belonged (active or placebo).

Conclusions Findings show a high nocebo adverse event rate suggesting significant nocebo effect in myasthenia gravis trials. This leads to decreased adherence to treatment hence increasing participant dropout rate in clinical trials. Despite this, the nocebo dropout rate is lowest amongst other studied neurological conditions (2.4%) suggesting a lack of peripheral nervous system involvement in the processing of nocebo.

Authors/Disclosures
Adithya Varma, MSc PRESENTER	No disclosure on file
Panagiotis Zis, MBBS, PhD (Sheffield Teaching Hospitals NHS Trust)	No disclosure on file

��ɫ��

��ɫ��