A Population-Based Study of Perforated Diverticular Disease Incidence and Associated Mortality

Background & Aims: Perforated diverticular disease represents the most serious complication of diverticular disease, but little is known regarding its occurrence and mortality. We aimed to determine the incidence and mortality associated with diverticular perforation and the influence of comorbidity. Methods: We used a population-based cohort study using patients with perforated diverticular disease and population controls identified from 1990 to 2005 in the General Practice Research Database (GPRD). Incidence and mortality rates were modelled using Poisson and Cox regression. Comorbidity was quantified using the Charlson index. Results: We identified 953 incident patients. The overall incidence was 2.66 (95% confidence interval [CI]: 2.49-2.83) per 100,000 person-years. The incidence rates increased 2.28-fold (95% CI: 1.79-2.95) when corrected for age and sex between 1990 and 2005. The risk of death was highest in the first year with a 6-fold increase (hazard ratio [HR], 5.63; 95% CI: 4.68 - 6.77). Adjusted for age and sex, the risk of death in the first year was highest in those with lowest comorbidity (HR, 11.11; 95% CI: 8.06-15.31), but the absolute mortality rates were greatest in those with the highest comorbidity (263.1 per 1000 person-years). Conclusions: The incidence of perforated diverticular disease has doubled over the period of the study. Patients presenting with a perforated diverticulum are 6 times more likely to die than the general population during the first year following perforation. Those who have the greatest comorbidity are the most likely to die; however, those with least comorbidity have an 11-fold increase in mortality in the first year.