The association between barium examination and subsequent appendicitis: a nationwide population-based study

Abstract Objective The incidence and association between appendicitis and barium examination (BE) remain unclear. Such potential risk may be omitted. We conducted a longitudinal, nationwide, population-based cohort study to investigate the association between BE and appendicitis risk. >Methods From the Taiwan National Health Insurance Research Database, a total of 24885 patients who underwent BE between January 1, 2000 and December 31, 2010 were enrolled in a BE cohort; additional 98384 subjects without BE exposure were selected as a non-BE cohort, matched by age, sex, and index date. The cumulative incidences of subsequent appendicitis in the BE and non-BE cohorts were assessed using the Kaplan–Meier curves and log-rank test. Cox proportional hazards regression analyses were employed to calculate the appendicitis risk between the groups. Results The cumulative incidence of appendicitis was higher in the BE cohort than in the non-BE cohort ( p = 0.001). The overall incidence rates of appendicitis for the BE and non-BE cohorts were 1.19 and 0.80 per 1,000 person-years, respectively. After adjustment for sex, age, and comorbidities, the risk of appendicitis was higher in the BE cohort (adjusted hazard ratio = 1.46, 95% confidence interval = 1.23–1.73) compared with the non-BE cohort, especially in the first 2 months (adjusted hazard ratio = 9.72, 95% confidence interval = 4.65–20.3). Conclusions BE was associated with an increased, time-dependent appendicitis risk. Clinicians should be aware of this potential risk to avoid delayed diagnoses.