In summary, analyses of the results of RCTs revealed positive findings in studies using nurses or nurse practitioners in the role of care manager. However, three studies reporting positive effects used the same sample with the same intervention from the Collaborative Care Model research. Only one article reported no significant differences, and this study’s outcome was persistence, not adherence. Even with those showing effectiveness, only cautious conclusions about achievements of superior adherence when involving nurses in care can be made. Because of the limited number of studies and disparities in designs, confidence in interventions is tentative.