Computerized provider order entry (CPOE) systems have been hailed as a solution to prevent medication errors and improve patient outcomes, particularly when combined with clinical decision support systems (CDSS). However, past reviews in 1998 and 2005 tempered this enthusiasm, suggesting a greater need for evaluation of such systems to ensure that their design and implementation optimize error prevention. This systematic review builds on past studies by analyzing the specific impact of electronic alerts and prompts (types of CDSS). Investigators found that most studies demonstrated positive and often significant impact on prescribing behavior. However, the authors caution that the specific design features that likely contributed to making a given system effective require further investigation.