Mortality risk increased in colonic diverticular disease: a nationwide cohort study.

Introduction: There are limited population cohort data on overall and cause-specific mortality in colonic diverticular disease.

Objective: To measure overall and cause-specific mortality in colonic diverticular disease, compared to matched reference individuals and siblings.

Methods: Population-based cohort study ("the ESPRESSO study") in Sweden. There were 97,850 cases with a medical diagnosis of diverticular disease (defined by international classification of disease codes) and colorectal histology identified in 1987-2017 from histopathology reports. The mortality risk between individuals with colonic diverticular disease and matched reference individuals (n = 453/634) from the general population was determined. Cox regression models adjusted for comorbidity estimated hazard ratios (HRs) for all-cause mortality.

Results: During follow-up, there were 32,959 deaths in individuals with colonic diverticular disease (44/1000 person-years) compared with 127,153 in matched reference individuals (34/1000 person-years), resulting in an HR of 1.27 (95%CI 1.25-1.29). Also compared to siblings, colonic diverticular disease patients were at increased risk of death, HR 1.39 (95%CI 1.33-1.45). Mortality risks were further increased in colonic diverticular disease patients with a colorectal biopsy showing any mucosal inflammation HR 1.36; (95%CI 1.33-1.38), with the most significant increase during the first year after diagnosis HR 2.18; (95%CI 2.05-2.32).

Conclusions: Mortality in colonic diverticular disease is increased over reference individuals in the general population. The presence of mucosal inflammation on colorectal biopsies is a predictor of increased risk of mortality.