PURPOSE: To evaluate the effects of social support on comprehension and recall of consent form information in a study of Parkinson disease patients and their caregivers.DESIGN and METHODS: Comparison of comprehension and recall outcomes among participants who read and signed the consent form accompanied by a family member/friend versus those of participants who read and signed the consent form unaccompanied. Comprehension and recall of consent form information were measured at one week and one month respectively, using Part A of the (...) Quality of Informed Consent Questionnaire .RESULTS: The mean age of the sample of 143 participants was 71 years . Analysis of covariance was used to compare QuIC scores between the intervention group and control group . In the 1-week model, no statistically significant intervention effect was found . However, the intervention status by patient status interaction was statistically significant . In the 1-month model, no statistically significant intervention effect was found . Again, however, the intervention status by patient status interaction was statistically significant . At both time periods, intervention group patients scored higher on the QuIC than did intervention group caregivers, and control group patients scored lower on the QuIC than did control group caregivers.IMPLICATIONS: Social support played a significant role in enhancing comprehension and recall of consent form information among patients. (shrink)