The correlation between cholecystectomy and seasonal impact in Taiwan

Many diseases and illnesses are known to be induced by changes in season and have seasonal fluctuations, and are affected by meteorological factors. Cholecystectomy is a very common surgical procedure used to treat gallstone disease and related complications. This study aimed to examine possible impacts of the seasons on the incidence of cholecystectomy with respect to gender and age as well as whether meteorological variables showed an association with incidences of cholecystectomy. The study was retrospectively conducted using the nationwide population-based datasets of National Health Insurance System in Taiwan. Patients who had undergone cholecystectomy were identified according to the International Classification of Diseases version 9 codes and categorized in terms of age and gender. Autoregression integrated moving average (ARIMA) multivariate models were applied to investigate the association of cholecystectomy incidence rates, time and meteorological variables. A total of 192,833 patients who underwent cholecystectomy between 1996 and 2008 were identified for the analysis. A trend indicating an overall increase was observed for the incidence rate of cholecystectomy over the study period. There were more females who underwent cholecystectomy than males. The highest incidence was found to occur during the summer and the lowest during the winter correlating with the cyclic pattern of temperature in Taiwan. Overall, the cholecystectomy incidence rate increased steadily over the 13-year study period for all age groups. In conclusion, the incidence of cholecystectomy was found to be correlated with the seasons. Temperature is the most notable variable among the relevant meteorological factors. Culture may also play a role in these correlations.