Comparing the accuracy of electronic dosing rules provided by a commercial vendor with traditional clinical dosing rules in pediatrics, this stimulation study found that the electronic rules were accurate only 55% of the time. This finding highlights the possible unintended consequences of health information technology (IT) on patient safety and underscores the specific challenge of pediatric medication prescribing. A recent AHRQ WebM&M commentary examines the complex issues around medication dosing for pediatric patients.