Seasonal Variation in Diverticulitis: Evidence from Both Hemispheres

BACKGROUND: Diverticulitis is a common and morbid disease with incompletely understood risk factors and pathophysiology. Geographic and, recently, seasonal trends in diverticulitis have been described in the United States. OBJECTIVE: The purpose of this study was to investigate and compare seasonal trends in urgent hospital admission for diverticulitis in geographically distinct populations in the northern and southern hemispheres. DESIGN: Inpatient, urgent admissions for diverticulitis were identified within the Dr Foster Intelligence Global Comparators Dataset, a global benchmarking collaborative. SETTINGS: Admissions to participating hospitals in the United Kingdom, Australia, and the United States were identified between 2008 and 2013. PATIENTS: A total of 18,672 urgent admissions for diverticulitis were identified among 5.5-million admissions. MAIN OUTCOME MEASURES: Four separate hypothesis testing methods were used to identify seasonal trends in diverticulitis admissions among international patient populations. RESULTS: Seasonal trends were present in all 3 countries. A summer peak was observed in both hemispheres using multiple statistical testing methods. Logistic regression analyses identified summer months as significantly associated with diverticulitis admission in all 3 countries. LIMITATIONS: This study is limited by restriction to inpatient admissions, reliance on administrative data, and participation of select hospitals within the database. CONCLUSIONS: These data suggest a shared seasonal risk factor among geographically distinct populations for diverticulitis.