Abstract: Objective To provide support for function adjustment of the adverse drug cluster events early warning system and improve the early warning ability. Methods More than 3 thousands early warning information in 2014 was analyzed systematically, and the risk factors influencing the early warning system were discussed. Results The risk factors included the early warning rules and algorithms, the quality of adverse drug reaction/event reports, foundation database, and the processing procedure for dealing with the early warning information of cluster adverse drug events. Conclusion The early warning system of the adverse drug cluster events can detect the product quality problem effectively. The function adjustment recommendations for the early warning system were proposed according to the identified risk factors.

Key words: cluster adverse drug events, early warning system, risk factor