Background and aim: The association between colonic diverticulosis, diverticulitis, and mortality is controversial. This study evaluated the association between diverticular disease and mortality over a prolonged period in a GP cohort.

Methods: GP records were sourced from the United Kingdom medical database (THIN). Diverticulosis and diverticulitis were identified via Read codes. The overall patient cohort (n = 1 274 260) included patients with colonic diverticula (n = 39 521 [3.1%], mean age 54) and no diverticula (control group) (n = 1 234 739 [96.9%], mean age 38). Poisson regression estimated relative rates, and durational time at risk and survival probability were calculated.

Results: Colonic diverticula are associated with an increased mortality risk when compared with nondiverticular patients (OR = 1.89, 95% CI 1.84-1.94; p < 0.001). However, controlling for age, sex, and potential confounding variables yielded a decreased mortality risk overall for colonic diverticula patients (HR = 0.66, 95% 0.64-0.6; p < 0.001). When the diverticulitis cohort is separated into uncomplicated and complicated, increased mortality is observed in both uncomplicated diverticulitis (HR = 0.64, 95% CI 0.61-0.66; p < 0.001) and complicated diverticulitis (HR = 1.14, 95% CI 1.02-1.28; p = 0.024), but on controlling for confounding, there is a decreased risk of mortality for uncomplicated diverticulitis (HR = 0.65, 95% CI 0.63-0.66; p < 0.001) but almost two times increased mortality risk for complicated diverticulitis (HR = 1.18, 95% CI 1.05-1.32; p = 0.006).

Conclusions: In this large UK GP sample, controlling for age, sex, and comorbidities, patients with uncomplicated diverticula are associated with a lower mortality risk. However, complicated diverticulitis still carries two times the risk of mortality than those with no or uncomplicated colonic diverticula.

Keywords: colon; diverticular disease; diverticulitis; diverticulosis; gastroenterology; mortality.

© 2025 The Author(s). Journal of Gastroenterology and Hepatology published by Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.