Epidemiology of Diverticulitis and Prevalence of First-Ever Colorectal Cancer Postdiverticulitis in Adults in the United States A Population-Based National Study

BACKGROUND: The incidence of acute diverticulitis is increasing, and previous studies showed a wide range of prevalence of colorectal cancer after diverticulitis. There is a lack of high-quality evidence to support performing colonoscopy after diverticulitis. OBJECTIVE: We aimed to describe the incidence of first-ever diverticulitis and prevalence of first-ever colorectal cancer postdiverticulitis in the United States. DESIGN: This is a retrospective cohort study. SETTINGS: We queried a national database that contains data from 26 major integrated healthcare systems in the United States. PATIENTS: We identified an aggregated patient cohort aged >= 18 years with a diagnosis of first-ever diverticulitis from February 2015 to February 2020, followed by first-ever colorectal cancer diagnosis, at least 1 day after and within 1 year of diverticulitis. MAIN OUTCOME MEASURES: The incidence of first-ever diverticulitis was calculated. The prevalence and OR of first-ever colorectal cancer after diverticulitis were analyzed. RESULTS: Among 31,778,290 individuals, we found the incidence of first-ever acute diverticulitis to be 2.9%. The prevalence of colorectal cancer within 1 year of first-ever acute diverticulitis was 0.57%, whereas the prevalence of colorectal cancer without a history of diverticulitis was 0.31% (OR = 1.8 (95% CI, 1.76-1.86)). The majority (92.3%) of the postdiverticulitis colorectal cancer were diagnosed within the first 6 months. The risk of colorectal cancer postdiverticulitis was higher in women (OR = 1.9), African Americans (OR = 2.0), and adults aged 18 to 65 years (OR = 2.3). LIMITATIONS: We are unable to validate the diagnostic code because patient information in our database is deidentified. CONCLUSIONS: Individuals are twice as likely to be diagnosed with colorectal cancer within 1 year of their first episode of acute diverticulitis compared with individuals without diverticulitis. We advocate for colonoscopy after the first occurrence of acute diverticulitis to screen for colorectal cancer, particularly for patients without a recent colonoscopy. See Video Abstract at http://links.lww.com/DCR/B412.