The occurrence of appendicitis varies according to latitudes and seasons: A French national retrospective study.

Background: Recent reports indicate that the occurrence of appendicitis follows a seasonal pattern and that there is an association between increased incidence and warmer weather. It is noteworthy that a reduction in the incidence of appendicitis has been observed in the Northern Hemisphere. The objective of this study is to present the epidemiological profile of appendicitis at the national level in France. Methods: This retrospective observational study, based on data from the French National Discharge Database, encompasses all hospitalizations for appendicitis diagnosis between 2013 and 2022. The progression of appendicitis over time was assessed through time-series models. The incidence of appendicitis was also compared depending on year, gender, age, and latitude. Results: It is noteworthy that the incidence of appendectomy in France exhibited a significant decrease between 2013 and 2022, with an average reduction of 2.1% annually. There was a significant decrease in the number of appendectomies performed on patients ≤20, while there was an increase in those >60. Furthermore, there was a seasonal pattern in the incidence of appendicitis, with a peak during the summer months. The seasonality remained consistent over time. Furthermore, there was a south-north gradient, with a higher number of appendectomies performed in the south. Conclusion: Seasonality (summer vs. winter) and latitude (south vs. north) could be considered as a proxy for temperature. However, temperature alone cannot explain the observed variations in appendicitis occurrence, since the latter decreases over time, in parallel with global warming. It is likely that other environmental and ecological parameters may be responsible for these variations.