 Questionnaires were used to collect the characteristic information of people living in Yuetan subdistrict in Beijing for more than 1 years people who had been hospitalized because of any reasons between July 2012 and June 2014 were selected.Patients were included in the study cohort when having, in association with a documented or strongly suspected infection and fullfil the diagnostic criteria of sepsis according to the Surviving Sepsis Campaign:International guidelines for management of severe sepsis and septic shock:2012. 