The research sought to evaluate whether providing personalized information services by libraries can improve satisfaction with information services for specific types of patients. Adult breast cancer (BrCa) clinic patients and mothers of inpatient neonatal intensive care unit (NICU) patients were randomized to receive routine information services (control) or an IRx intervention. The BrCa trial randomized 211 patients and the NICU trial, 88 mothers. The BrCa trial showed no statistically significant differences in satisfaction ratings between the treatment and control groups. The IRx group in the NICU trial reported higher satisfaction than the control group regarding information received about diagnosis, treatments, respiratory tradeoffs, and medication tradeoffs. BrCa patients posed questions to librarians more frequently than did NICU mothers, and a higher percentage reported using the website. Questions asked of the librarians by BrCa patients were predominantly clinical and focused on the areas of treatment and side effects. Study results provide some evidence to support further efforts to both implement information prescription projects in selected settings and to conduct additional research on the costs and benefits of services.