The introduction of computerized provider order entry (CPOE) systems has led to many readily apparent advantages, as well as some serious unintended consequences. This study investigated the effects of introducing a commercial CPOE system with very basic decision support at one hospital and a robust clinical decision support system at another. Both hospitals had used these programs for at least 2 years prior to the study. Negligible overall differences in the consequences were observed between the two systems. Although individuals reported that the computer system seemed to save time for some tasks, most users felt an overall increase in their workloads. Major barriers included the amount of time required to log in and inadequate computer infrastructure in clinical work environments. Clinicians demonstrated an array of workarounds to enhance efficiency, which often undercut patient safety. A previous AHRQ WebM&M interview discussed the unintended consequences of technology.