Maintaining the blind in sham controlled interventional trials: lessons from the EPISOD study

Area of Science:

• Gastroenterology
• Clinical Trials
• Endoscopic Procedures

Background:

• Sphincter of Oddi dysfunction (SOD) requires effective treatment evaluation.
• Sham-controlled trials are crucial for assessing endoscopic interventions.
• Maintaining blinding is essential for the validity of sham-controlled trials.

Purpose of the Study:

• To demonstrate blinding techniques used in the EPISOD study.
• To assess the effectiveness of blinding in a sham-controlled trial for SOD.
• To evaluate the success of subject blinding using the Bang's Blinding Index (BI).

Main Methods:

• Description of methods to ensure blinding of subjects, caregivers, and outcome assessors.
• Systematic assessment of subject blinding success using the Bang's Blinding Index (BI).
• Analysis of treatment allocation and confidence in perceived treatment.

Main Results:

• Blinding procedures were successfully implemented and adhered to by the study team.
• The BI indicated "wishful thinking" among subjects, irrespective of treatment allocation.
• Subject confidence in their treatment guess did not correlate with actual treatment assignment.

Conclusions:

• It is feasible to design and maintain blinding in sham-controlled endoscopic trials.
• Collecting treatment guess and confidence data is vital for assessing blinding success.
• The EPISOD study offers a model for future sham-controlled endoscopy trials.