Inpatient adverse drug events (ADEs) continue to be a major source of morbidity and mortality despite advances in computerized drug safety measures. Reports on the ability of computerized ADE alerts to prevent and mitigate ADEs are lacking. The aims of this project are to 1) Assess organizational, social, and cognitive factors that affect adoption of real-time ADE alerting technology; 2) Analyze the effect of the ADE alerting technology on management and rate of ADEs; and 3) Estimate the cost-benefit of the ADE alerting technology. This study will use a patient randomized design of computerized real-time ADE alerts intended for primary and secondary prevention of ADEs. The ADE alerts promise to reduce mortality, morbidity, and costs due to ADEs. This study will quantify the effect of the alerts in the hands of first-year medical residents and pharmacists. The study will explore the associations of organizational and soci-cognitive barriers and facilitators with the adoption of the ADE alert technology. At the cognitive level, it will explore whether ADE Alerts change user bias in diagnosing ADEs or whether the alerts heighten sensitivity to drug problems.