Abstract

CONTEXT:

Little is known about research participants' understanding of consent information over the course of a clinical study and the relationship of this information with participant behavior.

METHODS:

We conducted a cross sectional patient completed questionnaire of comprehension and satisfaction administered at the end of a Parkinson's disease clinical trial.

MAIN OUTCOME:

Scores on 9 comprehension items in a 30 item questionnaire covering the key elements of informed consent.

RESULTS:

78% of eligible trial participants completed this substudy. Greater than 90% of respondents showed good comprehension of the study purpose, method of treatment assignment, experimental nature of drugs, voluntary participation, and expected effect of the trial on their PD. However, 42.3% of subjects incorrectly endorsed that participating in the study was part of the "usual treatment" for their PD. We found no relationship between comprehension, compliance, and satisfaction with whether or not one's own neurologist was also the study doctor. Years of education and cognitive function at baseline were correlated with comprehension of study information.

CONCLUSIONS:

Overall comprehension of key study information presented in the consent was high after 12 months of trial participation, although there were inconsistencies in responses that need further study.