Seasonal variation in emergency surgical conditions

Abstract

Aim Seasonality has been shown to affect incidence of emergency surgical conditions in the West. There is yet no local data to suggest the causal relationship between seasonality and emergency surgical conditions. We aim to investigate on the effects of seasonal variation on common general surgical conditions for (i) ruptured abdominal aortic aneurysm, (ii) perforated peptic ulcer disease, (iii) ischaemic bowel, and (iv) acute cholecystitis in the New Territory West Cluster (NTWC). Method The present study was a retrospective study of 7653 patients who underwent emergency operations from 1 July 2008 to 30 June 2018 in the NTWC. Seasonality was defined according to the Chinese lunar calendar. Seasonal variation in the aforementioned surgical conditions were studied by emergency operations performed and recorded by the cluster's Surgical Outcomes Monitoring and Improvement Programme (SOMIP) data. The primary outcome is to analyse the presence of overall seasonal variation across the four seasons for each surgical condition by the goodness of fit test. The secondary outcome is to analyse the relationship of each season (Spring, Summer, Fall, Winter) and extreme weather condition, in this study, the cold weather warning signal, on the surgical conditions by the 2 × 2 Chi‐square test. Results For primary outcome, statistically significant variation exists in all general surgical conditions except ischaemic bowel across the four seasons. For secondary outcomes, statistically significant relationships exist between each season and different surgical conditions. Moreover, cold weather warning has a statistically significant relationship with emergent surgeries for perforated peptic ulcer disease and ruptured abdominal aortic aneurysm. Conclusion There is seasonal variation in emergency surgical conditions.