[Establishment of early warning control charts based on the syndromic surveillance data of outpatient diarrhea in Beijing].

Objective: To establish the control charts for early warning of diarrhea based on the syndromic surveillance data from enteric clinic in Beijing.

Methods: The outpatient data from enteric clinic of a Grade Three General hospital in Haidian district, Beijing from April 1 to Oct. 31, 2009 and from May 1 to Nov.