Evaluation of two communication tools, slideshow and theater, to improve participants' understanding of a clinical trial in the informed consent procedure on Pemba Island, Tanzania.

Our study confirmed that, in this setting, an ICF alone was not sufficient to convey clinical trial-related information. An IS was beneficial, however, additional theater and slideshows did not further improve understanding. Future research should explore methods to improve communication between study teams and participants for different key messages, study types and settings.