LAUSR

Objectives Seasonal variation on acute pancreatitis (AP) has not been investigated in Eastern Asia. The aims of the study were to assess the association of the onset of AP with the occurrence of seasons and Chinese festivals and to investigate trends in AP incidence in Shanghai, China. Methods From January 2009 to December 2014, a total of 1780 patients with AP were considered. The incidence was assessed by different etiology and severity. Monthly disease prevalence was investigated to explore the seasonal variation. The prevalence on weekdays, weekends, and festivals was evaluated to establish any weekly or festival influences in AP. Results Acute pancreatitis increased from 30.5 per 100,000 in 2009 to 39.2 in 2014 (5.1% annual increase), with greatest increases in alcoholic (19.8% annually) and severe AP (13.7% annually). Time series analysis indicated that prevalence was significantly higher form February to May (spring) and from September to October (autumn). Acute pancreatitis increased during Chinese festivals, 17% and 28% greater than that observed on weekdays and weekends, respectively. Prevalence was greatest in Chinese Spring Festival week. Conclusions Acute pancreatitis increased in Shanghai and had a seasonal variation, with a higher frequency of events in the spring and autumn. Chinese festivals are associated with a high prevalence of AP.