Nocebo Effect in Menière's Disease: A Meta-analysis of Placebo-controlled Randomized Controlled Trials.

OBJECTIVE: To estimate the frequency and strength of nocebo effects in trials for Menière disease (MD).

DATA SOURCES: A literature search was conducted in PUBMED. The search terms we used were " Menière or Menière's," "treatment," and "placebo." Limitations included article type to be Clinical Trial or Randomized Controlled Trial, text availability to be Full text, Species to be Humans and Language to be English.

STUDY SELECTION: We included placebo-controlled pharmaceutical RCTs that referred specifically to MD and recruited at least 10 adults in each arm. We excluded those studies with JADAD score ≤3.

DATA EXTRACTION: Thirty-six articles were screened identifying 12 eligible studies. Studies were included after consensus of both authors.

DATA SYNTHESIS: The meta-analysis was conducted using the RevMan programme as suggested by the Cochrane Collaboration Group. Data were analyzed using a random effects model.

CONCLUSION: Nocebo is an important confounding factor of the reported AEs in RCTs for treatment of MD and subsequently in the clinical practice. The pooled estimate of the percentage of placebo-treated patients with at least one AE was 42.3% (95% CI 8.1% to 16.3%), in comparison to 53.8% (95% CI 48.0% to 59.5%) for active drug-treated patients. Reporting of RCTs in MD is suboptimal and we recommend authors to endorse the CONSORT checklist.