Circadian and seasonal rhythms of acute upper gastrointestinal bleeding in Beijing.

Objective: To investigate the circadian and seasonal patterns in the presentation of acute upper gastrointestinal bleeding (AUGIB) in Beijing, China.

Methods: Medical records of the Beijing Emergency Medical Service System (EMSS) for 1 August 2005 to 31 July 2007 were reviewed; all patients diagnosed with AUGIB were included in the study.

Results: 2580 patients were recorded in the EMSS system with a diagnosis of AUGIB during the study period.