Determining the effectiveness of a decision aid for use in recruiting patients to a colon cancer vaccine trial

Purpose. A new colon cancer vaccine (CCV) to prevent recurrence soon will be tested in a Phase I clinical trial involving patients with early colon cancer. We studied the effectiveness of a decision aid designed to be used in trial recruitment. Methods. The research team designed an informational booklet for the CCV trial and recruited a convenience sample of patients. Patients were asked to read the booklet and complete a brief survey. The survey included 5 Likert-type items to indicate if the booklet was effective (based on agreement that the booklet was easy to read, explained the purpose of the trial well, clearly explained eligibility criteria, provided enough information, and adequately addressed patient safety and confidentiality). The survey also asked if respondents would recommend the booklet to others. Univariable and multivariable analyses identified factors associated with favorable responses (i.e., agreed with all survey items). Results. Of 37 patients in three urban hospital outpatient clinics and cancer registries, 7 were ineligible, 5 declined, and 25 completed the survey. Eleven (44%) respondents were > 65 years of age, 14 (56%) were female, 14 (56%) were white, 16 (64%) were married, and 14 (56%) had > high school education. Nineteen (76%) respondents found the decision aid effective. Multivariable analyses showed that older (> 65 years) patients were significantly less likely to find the booklet effective than younger patients (OR=0.86, CI: 0.76,0.98, p=0.0246). Conclusions. Decision aid effectiveness varied by patient age. Clinical trial decision aids should be designed with greater consideration for older adults.