What motivates Parkinson's disease patients to enter clinical trials?

Limited data is available regarding motivations and concerns of Parkinson's disease (PD) patients when participating in clinical trials (CTs). Knowledge of these factors may improve the recruitment and quality of future trials.

To assess the motivations and concerns of PD patients concerning participation in CTs and to evaluate the extent to which patients understand informed consent materials and placebo effect concept.

Cross-sectional study in PD patients enrolled in CTs between 2002 and 2007. Two questionnaires designed for placebo-controlled and active-controlled studies were mailed to patients.

From the 93/127 replied questionnaires (response rate: 73.2%) 91 were evaluable. Fifty-nine percent of the participants were women with a mean age of 66.8 years. The main reasons for participating in CTs were to help the advance of science (63.7%), to gain access to a better treatment (56.0%), and to benefit others (51.6%). Risk of adverse events (49.5%) and negative effects of treatment (35.2%) were the major concerns. Ninety percent reported they had understood the informed consent. Of 80 patients included in placebo-controlled studies, 63.9% understood the placebo effect concept. Globally, 66% of patients would participate in another CT and 41.6% in a placebo-controlled trial.

The main motivations of PD patients to participate in CTs were the benefit to the patient himself and to others. The major concern was safety. PD patients understood the informed consent, but more educational efforts must be made to explain the placebo effect. Most PD patients were very positive toward CTs and would participate in another trial.