A. Shmelev1, S. C. Cunningham1 1Saint Agnes Healthcare,Department Of Surgery,Baltimore, MARYLAND, USA
Introduction:
Circannual variation in certain acute medical and surgical conditions is a well-known phenomenon and has been described across the world. Among the most commonly reported are acute intra-abdominal pathologies such as acute appendicitis, pancreatitis, cholecystitis, inflammatory bowel disease (IBD). Various theories have been suggested to explain observed seasonal fluctuations in diseases rates. We aimed to describe seasonal variations in admission rates for a number of acute surgical diseases in the U.S. using a large administrative database.
Methods:
All admissions with primary diagnoses of acute appendicitis, diverticulitis, cholecystitis, pancreatitis, IBD, gastrointestinal ulcers (PUD) and bleeding (GIB), and bowel obstruction were pulled form AHRQ NIS (2000-2012; n=4.1 million). Monthly admission rates were calculated and seasonal trends decomposition was performed using LOESS or X-13 ARIMA procedures.
Results:
Acute intra-abdominal infections and IBD demonstrated the widest seasonal amplitude with peaks during summer months (the most prominent for acute infections) and troughs in cold season. GIB admission occurred predominantly in early spring with the fewest admissions in the end of summer. Nonbleeding PUD had plateaus during warm months and troughs in December. Regarding annual trends the fastest growth occurred for acute pancreatitis, diverticulitis, cholecystitis, IBD and bowel obstruction, followed by GIB. Conversely, admission rates for acute appendicitis and PUD have decreased over that time span.
Conclusion:
Analysis of large representative database re-demonstrated, that the incidence of most acute surgical conditions obeys certain circannual patterns. Literature indicated correlations of incidence trends of acute intra-abdominal pathologies with certain climatic parameters. Although no causation can be made based on these correlations, it is evident that diseases incidence is to a certain degree controlled by external factors which we can account for in resource planning. Additional, more granular analyses are necessary to uncover a possible role of air pollution, dehydration, circannual dietary changes and fluctuations in incidence of gastrointestinal infections, as a hypothetical cause of acute surgical pathologies.
