Epidemiological trends and geographic variation in hospital admissions for diverticulitis in the United States

AIM: To characterize the increasing incidence and geographic variation of acute diverticulitis. METHODS: Using the nationwide inpatient sample (NIS) we identified a cohort who had been admitted with diverticulitis between 1998 and 2005. We calculated age-, sex-, and region-specific rates of hospitalizations for diverticulitis over time. RESULTS: The age-adjusted hospitalization rate for diverticulitis increased from 61.8 per 100 000 to 75.5 per 100 000 between 1998 and 2005, and increased similarly in both sexes. Diverticulitis-associated admissions were male-predominant in those younger than age 45 years but were female-predominant thereafter. Admission rates increased the most among those < 45 years, while remaining unchanged for those ≥ 65 years. By 2005, the majority of hospitalized patients were < 65 years. Age-adjusted rates of diverticulitis-associated hospitalizations were lower in the West (50.4/100 000) compared to the Northeast (77.7/100 000), South (73.9/100 000), and Midwest (71.0/100 000). CONCLUSION: Diverticulitis-associated hospitalizations have steeply risen, especially in young adults. These epidemiological trends vary by geographic region and warrant further investigation into potential dietary and environmental etiologies.