Veteran subjects willingness to participate in schizophrenia clinical trials

Predictive characteristics of subjects agreeing to be randomized into clinical trials for the treatment of schizophrenia and schizoaffective disorder have been little studied. In this study, we used data from the recruitment phase of a randomized trial that compared long acting injectable (LAI) risperidone to oral antipsychotic medications. Basic socio-demographic and clinical data were gathered from eligible patients and clinicians at the time of screening for trial entry. Bivariate comparisons and multivariate logistic regression were used to compare those who agreed to participate and those who refused. Altogether 446 veterans were eligible on preliminary screening, of these 382 (86 %) agreed to participate and 64 (14 %) declined. Eligible patients who agreed to be randomized were more willing to change medications without regard to their level of satisfaction with their current medication. Subjects reported as currently taking LAI medication and taking risperidone, in particular, were more likely to agree to participate. Factors that did not significantly predict participation included age, years on current medication, reported medication compliance, race, and gender. Veterans with schizophrenia or schizoaffective disorder who were actually more satisfied with their current medications and who were currently taking the experimental agent were more likely to agree to participate in this randomized clinical trial in contrast to expectations that individuals who are unsatisfied with their current treatment would be more likely to enroll in such studies.