Increased Risk of Asthma in Children After Appendectomy: A Nationwide Population-based Cohort Study.

BACKGROUND/AIM: Appendectomy is a frequently performed surgical procedure, but its impact on immune function and gut microbiota remains unclear. Asthma, a chronic disease common in childhood, is linked to dysbiosis and immune dysregulation. This study aimed to assess asthma risk in children following appendectomy. PATIENTS AND METHODS: We analyzed 3,848 patients who had undergone appendectomy between 2000 and 2018 from Taiwan's National Health Insurance Research Database and matched them with 15,392 patients who had not undergone appendectomy. Propensity score-matching balanced age and sex at a 1:4 ratio. Multiple Cox regression and subgroup analysis were performed to investigate the relative risk of developing asthma following appendectomy. RESULTS: Adjusted for age and sex, appendectomy patients had a higher asthma risk [relative risk=1.23, 95% confidence interval (CI)=1.01-1.50; p=0.036]. Subgroup analysis showed that the risk of asthma following appendectomy was significantly higher in patients aged 12-18 years [hazard ratio (HR)=1.31, 95% CI=1.01-1.70; p=0.044] and in those with suburban residency (HR=1.49, 95% CI=1.08-2.05, p=0.015). Conversely, sex and family income did not significantly affect asthma risk. Furthermore, asthma risk did not significantly vary by follow-up duration (<1 year HR=1.58, p=0.090; 1-5 years HR=1.25, p=0.167; >5 years HR=1.11, p=0.488). CONCLUSION: These findings underscore the potential for the absence of the vermiform appendix to be associated with an increased risk of developing asthma, particularly in those aged 12-18 years. Pediatricians should be mindful of the possibility of asthma in children who have undergone appendectomy.